123 changed files with 1441 additions and 3798 deletions
--- a/.envrc
+++ b/.envrc
@ -1,7 +0,0 @@
-HOST_XDG_DATA_DIRS="${XDG_DATA_DIRS:-}"
-eval "$(lorri direnv)"
-export XDG_DATA_DIRS="${XDG_DATA_DIRS}:${HOST_XDG_DATA_DIRS}"
-
-# Use system PKI
-unset SSL_CERT_FILE
-unset NIX_SSL_CERT_FILE
--- a/.gitignore
+++ b/.gitignore
@ -1,9 +1,2 @@
 result
 result-*
-
-dist/
-dist-newstyle/
-cabal.project.local
-
-*.swp
-
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -1,100 +0,0 @@
-# Revision history for Arion
-
-## 0.2.1.0 -- 2023-07-26
-
-### Added
-
-* `service.networks` now supports attribute set values with various options, thanks to @pedorich-n.
-* `docker-compose.volumes` can now be specified in multiple modules, thanks to @qaifshaikh.
-* `image.fakeRootCommands` for making modifications to the image that aren't "add a link farm".
-
-### Fixed
-
-* Regular maintenance fixes, including one by olebedev
-
-
-## 0.2.0.0 -- 2022-12-02
-
-### BREAKING
-
-* The `project.name` option is now mandatory for projects that aren't deployed with the NixOS module.
-
-* The NixOS module now sets the default network name to the project name (commonly referred to as `<name>` in the option path).
-  If this is not desired, for instance if you need the projects to be on the same network, set `networks.default.name` in each of them.
-
-* The NixOS module now sets the default project name. You can still set your own value with the `project.name` option.
-  If you did not set one, docker compose heuristically determined the name to be `store`, so you may want to set `project.name = "store"` or prepare to rename the network manually.
-
-### Removed
-
- - NixOS 20.09 support. Its docker-compose does not support the
-   `networks.<name>.name` option, which is important in later versions.
-   A newer, bundled docker compose may work there, but for now the decision
-   is to drop this legacy version.
-
-### Changed
-
-* Healthcheck-based dependencies in `service.depends_on`.
-
-### Added
-
-* Support `service.healthcheck` for defining custom healthchecks.
-* Arion now declares a `networks.default` by default, with `name` set to
-  `project.name`. This improves compatibility with container runtimes by
-  copying pre-existing behavior. Most users will want to keep using this
-  behavior, but it can be disabled with `enableDefaultNetwork`.
-
-## 0.1.3.0 -- 2020-05-03
-
-### Changed
-
-* `useHostStore` now uses an image derived from the `image.*` options. You may
-  need to enable `enableRecommendedContents` because with this change, files
-  like `/bin/sh` aren't added by default anymore.
-
-* Drop obsolete NixOS 19.03, 19.09 and 20.03 from CI.
-
-### Added
-
-* NixOS-based containers can now run on Podman when it is configured to provide a docker socket. See the [installation docs](https://docs.hercules-ci.com/arion/#_nixos).
-
-* Support `service.dns`, for overriding the DNS servers used by containers.
-
-* Support `service.labels`, which is useful for autodiscovery among other things.
-
-* Add a tested example for Traefik with label-based routing.
-
-* Add a `flake.nix` and an experimental flake example
-
-* Add a warning when systemd `DynamicUser` is used but not available to the
-  container.
-
-* CI with NixOS 21.05
-
-## 0.1.2.0 -- 2020-03-05
-
-* Support use of prebuilt `docker-compose.yaml`.
-  Separates build and execution without duplicating evaluation.
-
-* Avoid storing tarballs (wasting store space) by using
-  `dockerTools.streamLayeredImage` if available.
-
-* Project name is now configurable via the `project.name` option
-
-* Support --no-ansi, --compatibility, --log-level options
-
-## 0.1.1.1 -- 2020-03-20
-
-* Fix ambiguous import of `lines`
-* Improve base version constraint
-* Fix warnings
-
-## 0.1.1.0 -- 2020-03-19
-
-* Support Nixpkgs 20.03
-* Fixes for macOS
-
-## 0.1.0.0 -- 2019-10-04
-
-* First released version. Released on an unsuspecting world.
-
--- a/HACKING.md
+++ b/HACKING.md
@ -1,31 +0,0 @@
-
-# Hacking on the modules
-
-## Easiest option
-
-The module system does not distinguish between modules and configurations.
-This mean you can prototype any feature by factoring out functionality in a real-world project.
-
-## Changing the built-in modules
-
-If your change is not just an addition or if it's better implemented by refactoring, you'll want to fork and edit arion sources directly.
-
-For a fast iteration cycle (but possibly outdated arion command logic):
-
-    ~/src/arion/run-arion-quick up -d
-
-To update the arion command logic on the next run
-
-    rm ~/src/arion/result-run-arion-quick
-
-
-# Hacking on the arion command
-
-The arion command is written in Haskell. Anyone can make small changes to the code.
-Experience with Haskell tooling is not required. You can use the nixified scripts in the root of the repo for common tasks.
- - `build` or `live-check` for typechecking
- - `live-unit-tests` (only the test suite is "live" though)
- - `repl` for a Haskell REPL
- - `run-arion` to run an incrementally built arion
- - `run-arion-via-nix` to run a nix-built arion
- - ~~`run-arion-quick`~~ *not for command hacking;* use stale command. See previous section.
--- a/2
+++ b/2
@ -187,7 +187,7 @@
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

-   Copyright 2019 Hercules Labs OÜ
+   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
--- a/README.asciidoc
+++ b/README.asciidoc
@ -1,7 +0,0 @@
-Arion is a tool for building and running applications that
-consist of multiple docker containers using NixOS modules.
-It has special support for docker images that are built with Nix,
-for a smooth development experience and improved performance.
-
-
-# https://docs.hercules-ci.com/arion/[Intro and Documentation]
--- a/README.md
+++ b/README.md
@ -0,0 +1,135 @@
+
+# Run docker-compose without images with Nix
+
+*Wait, what?*
+
+With Arion you can fire up containers without creating images for each
+service. It can use a mostly empty image, and makes the host's Nix
+store available in the container, allowing the container to run
+programs without having to re-package them into a docker image.
+
+Arion is configured using Nix with modules, like those in
+NixOS. Similar to `docker-compose` it can therefore combine
+configuration from multiple files. For managing the network and
+containers it delegates to the `docker-compose` command.
+
+# Project Status
+
+This project was born out of a process supervision need for local
+development environments while working
+on [Hercules CI](https://www.hercules-ci.com). (It was also born out
+of ancient Greek deities disguised as horses. More on that later.)
+
+If you do want to use Arion for production environments, you'll
+probably want to either build normal container images or manage
+garbage collection roots if you control the deployment host. Neither
+scenario is made easier by arion at this time.
+
+Support for other Linux than NixOS is untested.
+
+# Install
+
+Have [Nix](https://nixos.org/nix/) and Docker installed. Ubuntu users:
+make sure you've installed via `apt-get install docker.io`. The Docker snap
+is broken and apparently unsupported by Canonical.
+
+    git clone git@github.com:hercules-ci/arion.git
+    cd arion
+    nix-env -iA arion -f .
+
+# Example `arion-compose.nix`
+
+This Nix expression serves the Nix manual at host port 8000 when launched with `arion up`. It is a function from a package set (`pkgs`) to a configuration.
+
+```nix
+{ pkgs, ... }:
+{
+  config.docker-compose.services = {
+
+    webserver = {
+      service.useHostStore = true;
+      # service.depends_on = [ "backend" ];
+      service.command = [ "sh" "-c" ''
+                  cd "$$WEB_ROOT"
+                  ${pkgs.python3}/bin/python -m http.server
+                '' ];
+      service.ports = [
+        "8000:8000" # host:container
+      ];
+      service.environment.WEB_ROOT = "${pkgs.nix.doc}/share/doc/nix/manual";
+    };
+
+    # backend = { ... }
+  };
+}
+```
+
+The `pkgs` argument comes from a file called `arion-pkgs.nix`. It can be as simple as `import <nixpkgs> {}` to use the Nixpkgs from your `$NIX_PATH`, or you can use it to pin a specific Nixpkgs version.
+
+# A full featured example
+
+To see how Arion can be used in a project, have a look at [todomvc-nix](https://github.com/nix-community/todomvc-nix/tree/master/deploy/arion).
+
+    git clone git@github.com:nix-community/todomvc-nix.git
+    cd todomvc-nix/deploy/arion
+    arion up
+
+# How it works
+
+Arion is essentially a thin wrapper around Nix and docker-compose.
+When it runs, it does the following:
+
+ - Evaluate the configuration using Nix, producing a `docker-compose.yaml` and a garbage collection root
+ - Invoke `docker-compose`
+ - Clean up the garbage collection root
+
+Most of the interesting stuff happens in Arion's Nix expressions,
+where it runs the module system (known from NixOS) and provides the configuration that makes the Docker Compose file do the things it needs to do.
+
+One of the more interesting built-in modules is the [host-store.nix module](src/nix/modules/service/host-store.nix) which performs the bind mounts to make the host Nix store available in the container.
+
+# FAQ
+
+### Do I need to use Hercules CI?
+
+Nope, it's just Nix and Docker Compose under the hood.
+
+
+### Does Arion support Docker images?
+
+Yes, you can also specify a normal Docker image. For example:
+
+    postgres = {
+      service.image = "postgres:10";
+      service.volumes = [ "${toString ./.}/postgres-data:/var/lib/postgresql/data" ];
+      service.environment.POSTGRES_PASSWORD = "mydefaultpass";
+    };
+
+### What about garbage collection?
+
+Arion removes the need for garbage collecting docker images,
+delegating this task to Nix.
+
+Arion creates a garbage collection root and cleans it up after
+completing the command. This means that `arion up` without `-d` is
+safe with respect to garbage collection. A deployment that is more
+serious than local development must leave a GC root on the deployment
+host. This use case is not supported as of now.
+
+### What is messing with my environment variables?
+
+Docker Compose performs its own environment variable
+substitution. This can be a little annoying in `services.command` for
+example. Either reference a script from `pkgs.writeScript` or escape
+the dollar sign as `$$`.
+
+### Why "Arion"?
+
+Arion comes from Greek mythology. Poseidon, the god of ~Docker~ the
+seas had his eye on Demeter. Demeter tried to trick him by disguising
+as a horse, but Poseidon saw through the deception and they had Arion.
+
+So Arion is a super fast divine horse; the result of some weird
+mixing. Also it talks.
+
+(And we feel morally obliged to name our stuff after Greek mythology)
--- a/Setup.hs
+++ b/Setup.hs
@ -1,2 +0,0 @@
-import Distribution.Simple
-main = defaultMain
--- a/antora-playbook.yml
+++ b/antora-playbook.yml
@ -1,13 +0,0 @@
-# This is not used when the docs are imported into the docs site.
-# It is only here for development preview.
-content:
-  sources:
-  - url: .
-    start_path: docs
-    branches: HEAD
-ui:
-  bundle:
-    url: ./docs/ui-bundle.zip
-output:
-  dir: ./public
-
--- a/arion-compose.cabal
+++ b/arion-compose.cabal
@ -1,90 +0,0 @@
-cabal-version:       2.4
-
-name:                arion-compose
-version: 0.2.1.0
-synopsis:            Run docker-compose with help from Nix/NixOS
-description:         Arion is a tool for building and running applications that consist of multiple docker containers using NixOS modules. It has special support for docker images that are built with Nix, for a smooth development experience and improved performance.
-homepage:            https://github.com/hercules-ci/arion#readme
-- bug-reports:
-license:             Apache-2.0
-license-file:        LICENSE
-author:              Robert Hensing
-maintainer:          robert@hercules-ci.com
-- copyright:
-category:            Distribution, Network, Cloud, Distributed Computing
-extra-source-files:  CHANGELOG.md, README.asciidoc,
-                     src/haskell/testdata/**/*.nix
-                     src/haskell/testdata/**/*.json
-data-files:          nix/*.nix
-                   , nix/modules/composition/*.nix
-                   , nix/modules/networks/*.nix
-                   , nix/modules/nixos/*.nix
-                   , nix/modules/service/*.nix
-                   , nix/modules/lib/*.nix
-
-- all data is verbatim from some sources
-data-dir:            src
-
-source-repository head
-  type: git
-  location: https://github.com/hercules-ci/arion
-
-common common
-  build-depends:     base >=4.12.0.0 && <4.99
-                   , aeson >=2
-                   , aeson-pretty
-                   , async
-                   , bytestring
-                   , directory
-                   , lens
-                   , lens-aeson
-                   , process
-                   , temporary
-                   , text
-                   , protolude >= 0.2
-                   , unix
-  ghc-options:     -Wall
-
-flag ghci
-  default: False
-  manual: True
-
-library
-  import:              common
-  exposed-modules:     Arion.Nix
-                       Arion.Aeson
-                       Arion.DockerCompose
-                       Arion.ExtendedInfo
-                       Arion.Images
-                       Arion.Services
-  other-modules:       Paths_arion_compose
-  autogen-modules:     Paths_arion_compose
-  -- other-extensions:
-  hs-source-dirs:      src/haskell/lib
-  default-language:    Haskell2010
-
-executable arion
-  import:              common
-  main-is:             Main.hs
-  -- other-modules:
-  -- other-extensions:
-  build-depends:       optparse-applicative
-                     , arion-compose
-  hs-source-dirs:      src/haskell/exe
-  default-language:    Haskell2010
-
-test-suite arion-unit-tests
-  import:              common
-  if flag(ghci)
-    hs-source-dirs:      src/haskell/lib
-    ghc-options:       -Wno-missing-home-modules
-  type:                exitcode-stdio-1.0
-  main-is:             TestMain.hs
-  other-modules:       Spec
-                     , Arion.NixSpec
-  -- other-extensions:
-  build-depends:       arion-compose
-                     , hspec
-                     , QuickCheck
-  hs-source-dirs:      src/haskell/test
-  default-language:    Haskell2010
--- a/arion.nix
+++ b/arion.nix
@ -0,0 +1,38 @@
+{ stdenv, lib
+, coreutils, docker_compose, jq
+}:
+let
+
+  arion = stdenv.mkDerivation {
+    name = "arion";
+    src = ./src;
+    unpackPhase = "";
+    buildPhase = "";
+    installPhase = ''
+      mkdir -p $out/bin $out/share/arion
+      cp -a nix $out/share/arion/
+      cp -a arion-image $out/share/arion/
+      tar -czf $out/share/arion/arion-image/tarball.tar.gz -C arion-image/tarball .
+      substitute arion $out/bin/arion \
+        --subst-var-by path ${lib.makeBinPath [jq coreutils docker_compose]} \
+        --subst-var-by nix_dir $out/share/arion/nix \
+        ;
+      chmod a+x $out/bin/arion
+    '';
+    inherit passthru;
+  };
+
+  passthru = {
+    inherit eval build;
+  };
+
+  eval = import "${nix_dir}/eval-composition.nix";
+
+  build = args@{...}:
+    let composition = eval args;
+    in composition.config.build.dockerComposeYaml;
+
+  nix_dir = "${arion.outPath}/share/arion/nix";
+
+in
+  arion
--- a/bors.toml
+++ b/bors.toml
@ -1,5 +0,0 @@
-status = [
-  "ci/hercules/onPush/default",
-  "ci/hercules/evaluation",
-]
-delete_merged_branches = true
--- a/6
+++ b/6
@ -1,6 +0,0 @@
-#!/usr/bin/env nix-shell
-#!nix-shell -i bash
-
-# Build the Haskell package via cabal, outside Nix
-
-cabal new-build --write-ghc-environment-files=never
--- a/cabal.project
+++ b/cabal.project
@ -1 +0,0 @@
-packages: .
--- a/default.nix
+++ b/default.nix
@ -1,11 +1,6 @@
-let flake = import ./nix/compat.nix;
-in
-{ pkgs ? import flake.inputs.nixpkgs { }
-, haskellPackages ? pkgs.haskellPackages
-}:
-let
-  pkgsWithArion = pkgs.extend flake.overlays.default;
-in
+args@{ pkgs ? import ./nix args, ... }:
+
 {
-  inherit (pkgsWithArion) arion;
+  inherit (pkgs) arion tests;
+  doc = pkgs.recurseIntoAttrs (import ./doc { inherit pkgs; });
 }
--- a/doc/default.nix
+++ b/doc/default.nix
@ -0,0 +1,8 @@
+{ pkgs ? import ../nix {} }:
+let
+  inherit (pkgs) recurseIntoAttrs callPackage;
+in
+
+recurseIntoAttrs {
+  manual = callPackage ./manual {};
+}
--- a/doc/manual/.gitignore
+++ b/doc/manual/.gitignore
@ -0,0 +1,5 @@
+introduction.xml
+installation.xml
+manual.html
+options-composition.xml
+options-service.xml
--- a/doc/manual/Makefile
+++ b/doc/manual/Makefile
@ -0,0 +1,35 @@
+xsltproc = xsltproc --nonet \
+ --param section.autolabel 0 \
+ --param section.label.includes.component.label 0 \
+ --param chapter.autolabel 0 \
+ --param chapter.label.includes.component.label 0 \
+ --param appendix.autolabel 0 \
+ --param appendix.label.includes.component.label 0 \
+ --param generate.toc "'book toc,title chapter nop section nop sect1 nop sect2 nop sect3 nop sect4 nop sect5 nop'" \
+ --param html.stylesheet \'style.css\' \
+ --param xref.with.number.and.title 0 \
+ --param toc.section.depth 3 \
+ --param admon.style \'\' \
+ --param callout.graphics.extension \'.gif\' \
+ --param contrib.inline.enabled 0
+
+docbookxsl = http://docbook.sourceforge.net/release/xsl/current
+
+all: manual.html
+
+manual.html: manual.xml introduction.xml installation.xml options-composition.xml options-service.xml
+	$(xsltproc) --xinclude --stringparam profile.condition manual \
+	  $(docbookxsl)/profiling/profile.xsl manual.xml | \
+	  $(xsltproc) --output manual.html $(docbookxsl)/xhtml/docbook.xsl -
+
+# -e 's_<book lang="en">__' -e 's_</book>__'
+%.xml: %.asciidoc
+	asciidoctor --backend docbook45 --doctype article $<
+	sed -e 's/<!DOCTYPE.*//' -e 's/<?asciidoc-[a-z]*?>//' -i $@
+
+options-composition.xml options-service.xml:
+	echo "options-composition.xml and options-service.xml should be written by the derivation. Are you running in 'nix-shell -A manual'?"; exit 1; fi
+
+install: all
+	mkdir -p $(docdir)
+	cp manual.html style.css $(docdir)
--- a/doc/manual/build
+++ b/doc/manual/build
@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+nix-shell -A manual --run 'patchPhase && make'
--- a/doc/manual/default.nix
+++ b/doc/manual/default.nix
@ -0,0 +1,132 @@
+{ pkgs ? import ../../nix {}
+, version ? "none"
+# Default sourceUrl is for local development. Works with
+#   nix-build -A doc.manual
+# For release, use: https://github.com/hercules-ci/arion/blob/${version}
+, sourceUrl ? "../../.."
+}:
+let
+  inherit (pkgs) recurseIntoAttrs callPackage runCommand lib stdenv ;
+
+  nixosManualPath = s: "${pkgs.path}/nixos/doc/manual/${s}";
+
+  # NixOS module system options in JSON format.
+  options = { moduleType, description, /*optionsList*/ optionsExpr }: recurseIntoAttrs rec {
+    optionsXML =
+      # builtins.toFile "options.xml" (builtins.toXML optionsList);
+      pkgs.runCommand "options.xml" {
+        buildInputs = [pkgs.nix pkgs.jq];
+        inherit optionsExpr;
+      } ''
+        export NIX_LOG_DIR=$PWD
+        export NIX_STATE_DIR=$PWD
+        nix-instantiate \
+          --option sandbox false \
+          --readonly-mode \
+          --eval \
+          --expr "$optionsExpr" \
+          --xml \
+          --strict \
+          --show-trace \
+          >$out
+      '';
+
+    optionsDocBook = runCommand "options-db.xml" {} ''
+      optionsXML=${optionsXML}
+      ${pkgs.buildPackages.libxslt.bin}/bin/xsltproc \
+        --stringparam revision '${version}' \
+        --stringparam sourceUrl '${sourceUrl}' \
+        -o intermediate.xml ${./options-to-docbook.xsl} $optionsXML
+      ${pkgs.buildPackages.libxslt.bin}/bin/xsltproc \
+        -o "$out" ${nixosManualPath "postprocess-option-descriptions.xsl"} intermediate.xml
+    '';
+  };
+
+  compositionOptions = options {
+    moduleType = "composition";
+    description = "List of Arion composition-level options in JSON format";
+    optionsExpr = let
+      src = ../../src/nix;
+    in ''
+      let pkgs = import ${pkgs.path} {};
+          fixPaths = opt: opt // {
+            declarations = map (d: "src/nix" + (lib.strings.removePrefix (toString ${src}) (toString d))) opt.declarations;
+          };
+          inherit (pkgs) lib;
+          composition = import ${src}/eval-composition.nix { inherit pkgs; };
+      in map fixPaths (lib.filter (opt: opt.visible && !opt.internal) (lib.optionAttrSetToDocList composition.options))
+    '';
+  };
+
+  serviceOptions = options {
+    moduleType = "service";
+    description = "List of Arion service-level options in JSON format";
+    optionsExpr = let
+      src = ../../src/nix;
+    in ''
+      let pkgs = import ${pkgs.path} {};
+          fixPaths = opt: opt // {
+            declarations = map (d: "src/nix" + (lib.strings.removePrefix (toString ${src}) (toString d))) opt.declarations;
+          };
+          inherit (pkgs) lib;
+          composition = pkgs.callPackage ${src}/eval-service.nix {} { modules = []; host = {}; name = abort "The manual's service options section must not depend on the service name."; };
+      in map fixPaths (lib.filter (opt: opt.visible && !opt.internal) (lib.optionAttrSetToDocList composition.options))
+    '';
+  };
+
+  generatedDocBook = runCommand "generated-docbook" {} ''
+    mkdir $out
+    ln -s ${compositionOptions.optionsDocBook} $out/options-composition.xml
+    ln -s ${serviceOptions.optionsDocBook} $out/options-service.xml
+  '';
+
+  manual = stdenv.mkDerivation {
+    src = lib.sourceByRegex ./. [
+      "Makefile$"
+      ".*\.asciidoc$"
+      ".*\.xsl$"
+      ".*\.css$"
+      "^manual.xml$"
+      "^manual.xml$"
+    ];
+    name = "arion-manual";
+    version = version;
+    buildInputs = [
+      (pkgs.libxslt.bin or pkgs.libxslt)
+      pkgs.asciidoctor
+    ];
+    XML_CATALOG_FILES = "${pkgs.docbook_xsl}/xml/xsl/docbook/catalog.xml";
+    inherit generatedDocBook;
+    configurePhase = ''
+      export docdir=$out/doc
+    '';
+    postPatch = ''
+      substituteInPlace manual.xml --subst-var version
+    '';
+    prePatch = ''
+      cp ${generatedDocBook}/* .
+      substituteInPlace options-service.xml \
+        --replace 'xml:id="appendix-configuration-options"' 'xml:id="appendix-service-options"' \
+        --replace '<title>Configuration Options</title>' '<title>Service Options</title>' \
+        --replace 'xml:id="configuration-variable-list"' 'xml:id="service-variable-list"' \
+        ;
+      substituteInPlace options-composition.xml \
+        --replace 'xml:id="appendix-configuration-options"' 'xml:id="appendix-composition-options"' \
+        --replace '<title>Configuration Options</title>' '<title>Composition Options</title>' \
+        --replace 'xml:id="configuration-variable-list"' 'xml:id="composition-variable-list"' \
+        ;
+    '';
+    shellHook = ''
+      live-build() {
+        patchPhase
+        inotifywait -e MODIFY -m -r . | while read; do
+          make
+        done
+      }
+    '';
+    passthru = {
+      inherit generatedDocBook;
+    };
+  };
+in
+  manual
--- a/doc/manual/installation.asciidoc
+++ b/doc/manual/installation.asciidoc
@ -0,0 +1,39 @@
+
+= Installation
+
+== Imperative installation, bleeding edge
+
+```
+git clone git@github.com:hercules-ci/arion.git
+cd arion
+nix-env -iA arion -f .
+```
+
+// TODO: replace the above with something like below
+////
+
+== Not installing: use it in a project
+
+TODO: describe: using nix-shell or in a script, building images as
+      part of nix-build, pinning, see also todomvc-nix.
+
+TODO: exposed Nix functions: arion.build, arion.eval (a bit of IFD)
+
+== Mac or traditional Linux
+
+```
+nix-env -iA nixpkgs.arion
+```
+
+== NixOS
+
+Add this module to your NixOS configuration:
+
+```
+{ pkgs, ... } {
+  virtualisation.docker.enable = true;
+  environment.systemPackages = [ pkgs.arion ];
+}
+```
+
+////
--- a/doc/manual/introduction.asciidoc
+++ b/doc/manual/introduction.asciidoc
@ -0,0 +1,33 @@
+
+= Introduction
+
+Arion is a tool for building and running applications that
+consist of multiple docker containers. It has special support
+for docker images that are built with Nix, for a smooth
+development experience and improved performance.
+
+It is built on top of https://docs.docker.com/compose/overview/[Docker
+Compose], which implements the container orchestration functionality.
+
+Instead of configuring the compositions in YAML files like
+`docker-compose.yaml`, Arion uses the https://nixos.org/nix/[Nix]
+language to declare the compositions. Because of this, Arion gives you
+the ability to declare your deployments, configuration and packaging
+in the same language. By replacing multiple tools with a single
+language, you decrease your mental load and you can more easily
+refactor and maintain your configurations.
+
+Although Arion can be used as a Docker Compose with an improved
+configuration front end, there is more to be gained from integrating
+with Nix. In particular, the more structured approach of Nix compared
+to Dockerfiles allows the following:
+
+ * Build components of your image in _parallel, automatically_.
+ * Share packages between images, regardless of the order they were
+   added.
+ * Improve performance by _skipping_ container
+   image creation.
+ * Work with _structured data_ instead of strings,
+   templates and a multitude of expression languages.
+ * Refactor across deployments, configuration and
+   packaging.
--- a/doc/manual/live-build
+++ b/doc/manual/live-build
@ -0,0 +1,3 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -A manual
+#!nix-shell --run live-build
--- a/doc/manual/manual.xml
+++ b/doc/manual/manual.xml
@ -0,0 +1,25 @@
+<book xmlns="http://docbook.org/ns/docbook"
+      xmlns:xlink="http://www.w3.org/1999/xlink"
+      xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <info>
+
+    <title>Arion Manual</title>
+    <subtitle>Version none</subtitle>
+
+    <author>
+      <affiliation>
+        <orgname>Hercules Labs and other Arion contributors</orgname>
+      </affiliation>
+      <contrib>Author</contrib>
+    </author>
+
+  </info>
+
+  <xi:include href="introduction.xml" xpointer="xpointer(/article)" />
+  <xi:include href="installation.xml" xpointer="xpointer(/article)" />
+
+  <xi:include href="options-composition.xml" />
+  <xi:include href="options-service.xml" />
+
+</book>
--- a/doc/manual/options-to-docbook.xsl
+++ b/doc/manual/options-to-docbook.xsl
@ -0,0 +1,224 @@
+<?xml version="1.0"?>
+
+<xsl:stylesheet version="1.0"
+                xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+                xmlns:str="http://exslt.org/strings"
+                xmlns:xlink="http://www.w3.org/1999/xlink"
+                xmlns:nixos="tag:nixos.org"
+                xmlns="http://docbook.org/ns/docbook"
+                extension-element-prefixes="str"
+                >
+
+  <xsl:output method='xml' encoding="UTF-8" />
+
+  <xsl:param name="revision" />
+  <xsl:param name="program" />
+  <xsl:param name="sourceUrl" />
+  <xsl:param name="nixPathKey" />
+
+  <xsl:template match="/expr/list">
+    <appendix xml:id="appendix-configuration-options">
+      <title>Configuration Options</title>
+      <variablelist xml:id="configuration-variable-list">
+        <xsl:for-each select="attrs">
+          <xsl:variable name="id" select="concat('opt-', str:replace(str:replace(str:replace(str:replace(attr[@name = 'name']/string/@value, '*', '_'), '&lt;', '_'), '>', '_'), '?', '_'))" />
+          <varlistentry>
+            <term xlink:href="#{$id}">
+              <xsl:attribute name="xml:id"><xsl:value-of select="$id"/></xsl:attribute>
+              <option>
+                <xsl:value-of select="attr[@name = 'name']/string/@value" />
+              </option>
+            </term>
+
+            <listitem>
+
+              <nixos:option-description>
+                <para>
+                  <xsl:value-of disable-output-escaping="yes"
+                                select="attr[@name = 'description']/string/@value" />
+                </para>
+              </nixos:option-description>
+
+              <xsl:if test="attr[@name = 'type']">
+                <para>
+                  <emphasis>Type:</emphasis>
+                  <xsl:text> </xsl:text>
+                  <xsl:value-of select="attr[@name = 'type']/string/@value"/>
+                  <xsl:if test="attr[@name = 'readOnly']/bool/@value = 'true'">
+                    <xsl:text> </xsl:text>
+                    <emphasis>(read only)</emphasis>
+                  </xsl:if>
+                </para>
+              </xsl:if>
+
+              <xsl:if test="attr[@name = 'default']">
+                <para>
+                  <emphasis>Default:</emphasis>
+                  <xsl:text> </xsl:text>
+                  <xsl:apply-templates select="attr[@name = 'default']" mode="top" />
+                </para>
+              </xsl:if>
+
+              <xsl:if test="attr[@name = 'example']">
+                <para>
+                  <emphasis>Example:</emphasis>
+                  <xsl:text> </xsl:text>
+                  <xsl:choose>
+                    <xsl:when test="attr[@name = 'example']/attrs[attr[@name = '_type' and string[@value = 'literalExample']]]">
+                      <programlisting><xsl:value-of select="attr[@name = 'example']/attrs/attr[@name = 'text']/string/@value" /></programlisting>
+                    </xsl:when>
+                    <xsl:otherwise>
+                      <xsl:apply-templates select="attr[@name = 'example']" mode="top" />
+                    </xsl:otherwise>
+                  </xsl:choose>
+                </para>
+              </xsl:if>
+
+              <xsl:if test="attr[@name = 'relatedPackages']">
+                <para>
+                  <emphasis>Related packages:</emphasis>
+                  <xsl:text> </xsl:text>
+                  <xsl:value-of disable-output-escaping="yes"
+                                select="attr[@name = 'relatedPackages']/string/@value" />
+                </para>
+              </xsl:if>
+
+              <xsl:if test="count(attr[@name = 'declarations']/list/*) != 0">
+                <para>
+                  <emphasis>Declared by:</emphasis>
+                </para>
+                <xsl:apply-templates select="attr[@name = 'declarations']" />
+              </xsl:if>
+
+              <xsl:if test="count(attr[@name = 'definitions']/list/*) != 0">
+                <para>
+                  <emphasis>Defined by:</emphasis>
+                </para>
+                <xsl:apply-templates select="attr[@name = 'definitions']" />
+              </xsl:if>
+
+            </listitem>
+
+          </varlistentry>
+
+        </xsl:for-each>
+
+      </variablelist>
+    </appendix>
+  </xsl:template>
+
+
+  <xsl:template match="*" mode="top">
+    <xsl:choose>
+      <xsl:when test="string[contains(@value, '&#010;')]">
+<programlisting>
+<xsl:text>''
+</xsl:text><xsl:value-of select='str:replace(string/@value, "${", "&apos;&apos;${")' /><xsl:text>''</xsl:text></programlisting>
+      </xsl:when>
+      <xsl:otherwise>
+        <literal><xsl:apply-templates /></literal>
+      </xsl:otherwise>
+    </xsl:choose>
+  </xsl:template>
+
+
+  <xsl:template match="null">
+    <xsl:text>null</xsl:text>
+  </xsl:template>
+
+
+  <xsl:template match="string">
+    <xsl:choose>
+      <xsl:when test="(contains(@value, '&quot;') or contains(@value, '\')) and not(contains(@value, '&#010;'))">
+        <xsl:text>''</xsl:text><xsl:value-of select='str:replace(@value, "${", "&apos;&apos;${")' /><xsl:text>''</xsl:text>
+      </xsl:when>
+      <xsl:otherwise>
+        <xsl:text>"</xsl:text><xsl:value-of select="str:replace(str:replace(str:replace(str:replace(@value, '\', '\\'), '&quot;', '\&quot;'), '&#010;', '\n'), '$', '\$')" /><xsl:text>"</xsl:text>
+      </xsl:otherwise>
+    </xsl:choose>
+  </xsl:template>
+
+
+  <xsl:template match="int">
+    <xsl:value-of select="@value" />
+  </xsl:template>
+
+
+  <xsl:template match="bool[@value = 'true']">
+    <xsl:text>true</xsl:text>
+  </xsl:template>
+
+
+  <xsl:template match="bool[@value = 'false']">
+    <xsl:text>false</xsl:text>
+  </xsl:template>
+
+
+  <xsl:template match="list">
+    [
+    <xsl:for-each select="*">
+      <xsl:apply-templates select="." />
+      <xsl:text> </xsl:text>
+    </xsl:for-each>
+    ]
+  </xsl:template>
+
+
+  <xsl:template match="attrs[attr[@name = '_type' and string[@value = 'literalExample']]]">
+    <xsl:value-of select="attr[@name = 'text']/string/@value" />
+  </xsl:template>
+
+
+  <xsl:template match="attrs">
+    {
+    <xsl:for-each select="attr">
+      <xsl:value-of select="@name" />
+      <xsl:text> = </xsl:text>
+      <xsl:apply-templates select="*" /><xsl:text>; </xsl:text>
+    </xsl:for-each>
+    }
+  </xsl:template>
+
+
+  <xsl:template match="derivation">
+    <replaceable>(build of <xsl:value-of select="attr[@name = 'name']/string/@value" />)</replaceable>
+  </xsl:template>
+
+  <xsl:template match="attr[@name = 'declarations' or @name = 'definitions']">
+    <simplelist>
+      <xsl:for-each select="list/string">
+        <member><filename>
+          <!-- Hyperlink the filename either to the NixOS Subversion
+          repository (if it’s a module and we have a revision number),
+          or to the local filesystem. -->
+          <xsl:choose>
+            <xsl:when test="not(starts-with(@value, '/'))">
+              <xsl:attribute name="xlink:href"><xsl:value-of select="$sourceUrl"/>/<xsl:value-of select="@value"/></xsl:attribute>
+            </xsl:when>
+            <xsl:otherwise>
+              <xsl:attribute name="xlink:href">file://<xsl:value-of select="@value"/></xsl:attribute>
+            </xsl:otherwise>
+          </xsl:choose>
+          <!-- Print the filename and make it user-friendly by replacing the
+          /nix/store/<hash> prefix by the default location of nixos
+          sources. -->
+          <xsl:choose>
+            <xsl:when test="$nixPathKey != ''">
+              &lt;<xsl:value-of select="$nixPathKey"/>/<xsl:value-of select="@value"/>&gt;
+            </xsl:when>
+            <xsl:otherwise>
+              <xsl:value-of select="@value" />
+            </xsl:otherwise>
+          </xsl:choose>
+        </filename></member>
+      </xsl:for-each>
+    </simplelist>
+  </xsl:template>
+
+
+  <xsl:template match="function">
+    <xsl:text>λ</xsl:text>
+  </xsl:template>
+
+
+</xsl:stylesheet>
--- a/doc/manual/style.css
+++ b/doc/manual/style.css
@ -0,0 +1,159 @@
+
+hr { color: #ddd; margin-top: 3ex; }
+h1, h2, h3, h4 { font-weight: bold; }
+h1 { font-size: 200%; margin-top: 5ex; }
+h2 { font-size: 160%; margin-top: 4ex; }
+h3,h4 { font-size: 120%; margin-top: 3ex; }
+
+/* From Semantic UI */
+body {
+  font-family: Lato,'Helvetica Neue',Arial,Helvetica,sans-serif;
+  font-size: 14px;
+  line-height: 1.4285em;
+  color: rgba(0,0,0,.87);
+}
+
+code.literal {
+    background-color: #f7f7f7;
+}
+
+a {
+ background-color:transparent;
+ -webkit-text-decoration-skip:objects
+}
+a {
+ color:#4183c4;
+ text-decoration:none
+}
+a:hover {
+ color:#1e70bf;
+ text-decoration:none
+}
+::-webkit-selection {
+ background-color:#cce2ff;
+ color:rgba(0,0,0,.87)
+}
+::-moz-selection {
+ background-color:#cce2ff;
+ color:rgba(0,0,0,.87)
+}
+::selection {
+ background-color:#cce2ff;
+ color:rgba(0,0,0,.87)
+}
+
+/* toc menu */
+@media screen and (min-width: 60em) {
+  body {
+    margin-left: 16.5em; 
+  }
+  div.toc {
+    position: fixed;
+    top: 0pt;
+    left: 1em;
+    height: 100%;
+    overflow-y: auto;
+    width: 15.5em;
+  }
+}
+@media screen and (min-width: 90em) {
+  div.toc {
+    left: 5em;
+  }
+}
+/* hide per chapter toc */
+div.chapter div.toc {
+    display: none;
+}
+
+
+/* From Nixpkgs: */
+
+div.book
+{
+    text-align: center;
+}
+
+div.book > div
+{
+    /*
+     * based on https://medium.com/@zkareemz/golden-ratio-62b3b6d4282a
+     * we do 70 characters per line to fit code listings better
+     * 70 * (font-size / 1.618)
+     * expression for emacs:
+     * (* 70 (/ 1 1.618))
+     */
+    max-width: 43.2em;
+    text-align: left;
+    margin: auto;
+}
+
+
+/***************************************************************************
+                               Special elements:
+ ***************************************************************************/
+
+.term
+{
+    font-weight: bold;
+
+}
+
+div.variablelist dd p, div.glosslist dd p
+{
+    margin-top: 0em;
+}
+
+div.variablelist dd, div.glosslist dd
+{
+    margin-left: 1.5em;
+}
+
+div.glosslist dt
+{
+    font-style: italic;
+}
+
+.varname
+{
+    color: #004000;
+}
+
+span.command strong
+{
+    font-weight: normal;
+    color: #004000;
+}
+
+div.calloutlist table
+{
+    box-shadow: none;
+}
+
+table
+{
+    border-collapse: collapse;
+    box-shadow: 0.4em 0.4em 0.5em #e0e0e0;
+}
+
+table.simplelist
+{
+    text-align: left;
+    color: #005aa0;
+    border: 0;
+    padding: 5px;
+    background: #fffff5;
+    font-weight: normal;
+    font-style: italic;
+    box-shadow: none;
+    margin-bottom: 1em;
+}
+
+div.navheader table, div.navfooter table {
+    box-shadow: none;
+}
+
+div.affiliation
+{
+    font-style: italic;
+}
--- a/docs/README.md
+++ b/docs/README.md
@ -1,4 +0,0 @@
-
-# Documentation
-
-Please refer to the [**rendered documentation**](https://docs.hercules-ci.com/arion), which includes the [**options.**](https://docs.hercules-ci.com/arion/options/)
--- a/docs/antora.yml
+++ b/docs/antora.yml
@ -1,7 +0,0 @@
-name: arion
-title: Arion Documentation
-version: 'master'
-nav:
- modules/ROOT/nav.adoc
- modules/reference/nav.adoc
-nix: true
--- a/docs/flake-module.nix
+++ b/docs/flake-module.nix
@ -1,31 +0,0 @@
-{
-  perSystem = { config, pkgs, lib, ... }: {
-    packages.generated-option-doc-arion =
-      # TODO: use the render pipeline in flake-parts,
-      #       which has support for things like {options}`foo`.
-      let
-        eval = lib.evalModules {
-          modules = import ../src/nix/modules.nix;
-        };
-      in
-      (pkgs.nixosOptionsDoc
-        {
-          options = eval.options;
-        }).optionsCommonMark;
-
-    packages.generated-antora-files =
-      pkgs.runCommand "generated-antora-files"
-        {
-          nativeBuildInputs = [ pkgs.pandoc ];
-          doc_arion = config.packages.generated-option-doc-arion;
-        }
-        # TODO: use the render pipeline in flake-parts,
-        #       which has support for things like {options}`foo`.
-        ''
-          mkdir -p $out/modules/ROOT/partials
-          pandoc --from=markdown --to=asciidoc \
-            < $doc_arion \
-            > $out/modules/ROOT/partials/arion-options.adoc
-        '';
-  };
-}
--- a/docs/modules/ROOT/examples/full-nixos/arion-compose.nix
+++ b/docs/modules/ROOT/examples/full-nixos/arion-compose.nix
@ -1 +0,0 @@
-../../../../../examples/full-nixos/arion-compose.nix
--- a/docs/modules/ROOT/examples/minimal/arion-compose.nix
+++ b/docs/modules/ROOT/examples/minimal/arion-compose.nix
@ -1 +0,0 @@
-../../../../../examples/minimal/arion-compose.nix
--- a/docs/modules/ROOT/examples/nixos-unit/arion-compose.nix
+++ b/docs/modules/ROOT/examples/nixos-unit/arion-compose.nix
@ -1 +0,0 @@
-../../../../../examples/nixos-unit/arion-compose.nix
--- a/docs/modules/ROOT/nav.adoc
+++ b/docs/modules/ROOT/nav.adoc
@ -1,3 +0,0 @@
-* xref:index.adoc[Getting Started]
-* xref:options.adoc[Arion Options]
-* xref:deployment.adoc[Deployment]
--- a/docs/modules/ROOT/pages/deployment.adoc
+++ b/docs/modules/ROOT/pages/deployment.adoc
@ -1,71 +0,0 @@
-= Deployment with Arion
-
-Arion projects can be deployed in Nix-like or Docker-like ways.
-
-== Docker images
-
-When you disable `useHostStore`, arion will build images, which can be deployed
-to any Docker host, including non-NixOS hosts.
-
-=== Remote Docker socket
-
-NOTE: Access to a Docker socket is equivalent to root access on the host.
-
-Docker supports authentication via TLS client certificates.
-
-The xref:hercules-ci-effects:ROOT:reference/nix-functions/runArion.adoc[runArion Effect] uses this technique.
-
-Because this technique works with a single Docker host, it does not need a registry.
-
-=== Upload to registry
-
-You can either use `arion push` or write custom push logic using the `arion cat`
-command, the `eval` function on the `arion` package, or the `lib.eval` function
-on the flake to retrieve the images defined in a project.
-
-== NixOS module
-
-Arion projects can be deployed as part of a NixOS configuration. This ties the
-project revision to the system configuration revision, which can be good or bad
-thing, depending on your deployment strategy. At a low level, a benefit is that
-no store paths need to be copied locally and remote NixOS deployments can use
-Nix's copy-closure algorithm for efficient transfers, and transparent binary
-caches rather than an inherently stateful Docker registry solution.
-
-Extend your NixOS configuration by adding the configuration elements to an
-existing configuration. You could create a new module file for it, if your
-choice of `imports` allows it.
-
-NOTE: This deployment method does NOT use an `arion-pkgs.nix` file, but reuses
-      the host `pkgs`.
-
-```nix
-{
-  imports = [
-    # Pick one of:
-    #  - niv
-    ((import ./nix/sources.nix).arion + "/nixos-module.nix")
-    #  - or flakes (where arion is a flake input)
-    arion.nixosModules.arion
-    #  - or other: copy commit hash of arion and replace HASH in:
-    (builtins.fetchTarball "https://github.com/hercules-ci/arion/archive/HASH.tar.gz") + "/nixos-module.nix")
-  ];
-
-  virtualisation.arion = {
-    backend = "podman-socket"; # or "docker"
-    projects.example = {
-      serviceName = "example"; # optional systemd service name, defaults to arion-example in this case
-      settings = {
-        # Specify you project here, or import it from a file.
-        # NOTE: This does NOT use ./arion-pkgs.nix, but defaults to NixOS' pkgs.
-        imports = [ ./arion-compose.nix ];
-      };
-    };
-  };
-}
-```
-
-See also:
-
- - xref:hercules-ci-effects:ROOT:reference/nix-functions/runNixOS.adoc[runNixOS Effect]
- - xref:hercules-ci-effects:ROOT:reference/nix-functions/runNixOps2.adoc[runNixOps2 Effect]
--- a/docs/modules/ROOT/pages/index.adoc
+++ b/docs/modules/ROOT/pages/index.adoc
@ -1,312 +0,0 @@
-= Welcome to Arion documentation
-
-== Introduction
-
-Arion is a tool for building and running applications that
-consist of multiple docker containers using NixOS modules.
-It has special support for docker images that are built with Nix,
-for a smooth development experience and improved performance.
-
-It is built on top of https://docs.docker.com/compose/overview/[Docker
-Compose], which implements the container orchestration functionality.
-
-Instead of configuring the compositions in YAML files like
-`docker-compose.yaml`, Arion uses the https://nixos.org/nix/[Nix]
-language to declare the compositions. Because of this, Arion gives you
-the ability to declare your deployments, configuration and packaging
-in the same language. By replacing multiple tools with a single
-language, you decrease your mental load and you can more easily
-refactor and maintain your configurations.
-
-Although Arion can be used as a Docker Compose with an improved
-configuration front end, there is more to be gained from integrating
-with Nix. In particular, the more structured approach of Nix compared
-to Dockerfiles allows the following:
-
- * Build components of your image in *parallel, automatically*
- * *Share packages between images*, regardless of the order they were
-   added
- * Improve performance by *skipping container
-   image creation*
- * Work with *structured data instead of strings*,
-   templates and a multitude of expression languages
- * Refactor across deployments, configuration and packaging
-
-Arion allows to compose containers with different granularity:
-
-  * <<Minimal: Plain command using nixpkgs>>
-  * <<NixOS: run only one systemd service>>
-  * <<NixOS: run full OS>>
-  * <<Docker image from DockerHub>>
-
-Full NixOS is supported on
-
- * docker-compose + podman with docker socket (NixOS >= 21.05)
- * docker-compose + docker, before cgroupsv2 (NixOS < 21.05)
-
-`podman-compose` support is currently WIP on a separate branch.
-
-== Installation
-
-=== Nix
-
-```bash
-$ nix-env -iA arion -f https://github.com/hercules-ci/arion/tarball/master
-```
-
-=== NixOS
-
-Add this module to your NixOS configuration:
-
-```nix
-{ pkgs, ... }: {
-  environment.systemPackages = [
-    pkgs.arion
-
-     # Do install the docker CLI to talk to podman.
-     # Not needed when virtualisation.docker.enable = true;
-    pkgs.docker-client
-  ];
-
-  # Arion works with Docker, but for NixOS-based containers, you need Podman
-  # since NixOS 21.05.
-  virtualisation.docker.enable = false;
-  virtualisation.podman.enable = true;
-  virtualisation.podman.dockerSocket.enable = true;
-  virtualisation.podman.defaultNetwork.dnsname.enable = true;
-
-  # Use your username instead of `myuser`
-  users.extraUsers.myuser.extraGroups = ["podman"];
-}
-```
-
-////
-
-== Not installing: use it in a project
-
-TODO: describe: using nix-shell or in a script, building images as
-      part of nix-build, pinning, see also todomvc-nix.
-
-TODO: exposed Nix functions: arion.build, arion.eval (a bit of IFD)
-
-
-////
-
-
-== Usage
-
-Arion is configured declaratively with two files:
-
-=== arion-pkgs.nix
-
-Arion needs `arion-pkgs.nix` to import nixpkgs, for example:
-
-```nix
-import <nixpkgs> { system = "x86_64-linux"; }
-```
-
-or more sophisticated (recommended) setup with https://github.com/nmattia/niv[Niv].
-
-=== arion-compose.nix
-
-Describe containers using NixOS-style modules. There are a few options:
-
-==== Minimal: Plain command using nixpkgs
-
-`examples/minimal/arion-compose.nix`
-[,nix]
----
-{ pkgs, ... }:
-{
-  project.name = "webapp";
-  services = {
-
-    webserver = {
-      image.enableRecommendedContents = true;
-      service.useHostStore = true;
-      service.command = [ "sh" "-c" ''
-                  cd "$$WEB_ROOT"
-                  ${pkgs.python3}/bin/python -m http.server
-                '' ];
-      service.ports = [
-        "8000:8000" # host:container
-      ];
-      service.environment.WEB_ROOT = "${pkgs.nix.doc}/share/doc/nix/manual";
-      service.stop_signal = "SIGINT";
-    };
-  };
-}
----
-
-==== NixOS: run full OS
-
-`examples/full-nixos/arion-compose.nix`:
-
-[,nix]
----
-{
-  project.name = "full-nixos";
-  services.webserver = { pkgs, lib, ... }: {
-    nixos.useSystemd = true;
-    nixos.configuration.boot.tmp.useTmpfs = true;
-    nixos.configuration.services.nginx.enable = true;
-    nixos.configuration.services.nginx.virtualHosts.localhost.root = "${pkgs.nix.doc}/share/doc/nix/manual";
-    nixos.configuration.services.nscd.enable = false;
-    nixos.configuration.system.nssModules = lib.mkForce [];
-    nixos.configuration.systemd.services.nginx.serviceConfig.AmbientCapabilities = 
-      lib.mkForce [ "CAP_NET_BIND_SERVICE" ];
-    service.useHostStore = true;
-    service.ports = [
-      "8000:80" # host:container
-    ];
-  };
-}
----
-
-==== Docker image from DockerHub
-
-```nix
-{
-  services.postgres = {
-    service.image = "postgres:10";
-    service.volumes = [ "${toString ./.}/postgres-data:/var/lib/postgresql/data" ];
-    service.environment.POSTGRES_PASSWORD = "mydefaultpass";
-  };
-}
-```
-
-==== NixOS: run only one systemd service
-
-Running individual units from NixOS is possible using an experimental script.
-See `examples/nixos-unit/arion-compose.nix`.
-
-=== Run
-
-Start containers and watch their logs:
-
-```bash
-$ arion up -d
-$ arion logs -f
-```
-
-You can go to `examples/*/` and run these commands to give it a quick try.
-
-=== Inspect the config
-
-While developing an arion project, you can make use of `arion repl`, which launches
-a `nix repl` on the project configuration.
-
-```
-$ arion repl
-Launching a repl for you. To get started:
-
-To see deployment-wide configuration
-  type config. and use tab completion
-To bring the top-level Nixpkgs attributes into scope
-  type :a (config._module.args.pkgs) // { inherit config; }
-
-Welcome to Nix. Type :? for help.
-
-Loading '../../src/nix/eval-composition.nix'...
-Added 5 variables.
-
-nix-repl> config.services.webserver.service.command
-[ "sh" "-c" "cd \"$$WEB_ROOT\"\n/nix/store/66fbv9mmx1j4hrn9y06kcp73c3yb196r-python3-3.8.9/bin/python -m http.server\n" ]
-
-nix-repl>
-
-```
-
-== Build with Nix
-
-You can build a project with `nix-build` using an expression like
-
-```nix
-arion.build { modules = [ ./arion-compose.nix ]; pkgs = import ./arion-pkgs.nix; }
-```
-
-If you deploy with xref:hercules-ci-effects:ROOT:reference/nix-functions/runArion.adoc[runArion],
-and your `pkgs` variable is equivalent to `import ./arion-pkgs.nix`, you can use:
-
-```nix
-let
-  deployment = pkgs.effects.runArion { /* ... */ });
-in deployment.prebuilt
-```
-
-== Project Status
-
-This project was born out of a process supervision need for local
-development environments while working on
-https://www.hercules-ci.com[Hercules CI]. (It was also born out of
-ancient Greek deities disguised as horses. More on that later.)
-
-Arion can be used for simple single host deployments, using Docker's TLS
-client verification, or https://search.nixos.org/options?channel=unstable&show=virtualisation.podman.networkSocket.enable&query=virtualisation.podman[`virtualisation.podman.networkSocket` options].
-Remote deployments do not support `useHostStore`, although an SSH-based deployment method could support this.
-Docker Swarm is not currently supported.
-
-Arion has run successfully on Linux distributions other than NixOS, but we only perform CI for Arion on NixOS.
-
-
-== How it works
-
-Arion is essentially a thin wrapper around Nix and docker-compose. When
-it runs, it does the following:
-
-* Evaluate the configuration using Nix, producing a
-`docker-compose.yaml` and a garbage collection root
-* Invoke `docker-compose`
-* Clean up the garbage collection root
-
-Most of the interesting stuff happens in Arion’s Nix expressions, where
-it runs the module system (known from NixOS) and provides the
-configuration that makes the Docker Compose file do the things it needs
-to do.
-
-One of the more interesting built-in modules is the
-https://github.com/hercules-ci/arion/blob/master/src/nix/modules/service/host-store.nix[host-store.nix module] which
-performs the bind mounts to make the host Nix store available in the
-container.
-
-== FAQ
-
-=== Do I need to use Hercules CI?
-
-Nope, it’s just Nix and Docker Compose under the hood.
-
-It does xref:hercules-ci-effects:ROOT:reference/nix-functions/runArion.adoc[integrate] nicely though.
-
-=== What about garbage collection?
-
-Arion removes the need for garbage collecting docker images, delegating
-this task to Nix when using `service.useHostStore`.
-
-Arion creates a garbage collection root that it cleans up after completing
-the command. This means that `arion up -d` should not be used with `useHostStore`
-in production. Instead, disable `useHostStore`, which will use `dockerTools` to
-generate images that can be used in production.
-
-=== Why is my container not running latest code?
-
-Rebuild the image using `arion up -d --always-recreate-deps <name>` or simply `arion up -d`.
-
-Like `docker-compose restart`, `arion restart` does not update the image before starting.
-
-=== What is messing with my environment variables?
-
-Docker Compose performs its own environment variable substitution. This
-can be a little annoying in `services.command` for example. Either
-reference a script from `pkgs.writeScript` or escape the dollar sign as
-`$$`.
-
-=== Why name it ``Arion``?
-
-Arion comes from Greek mythology. Poseidon, the god of Docker -- I mean the seas --
-had his eye on Demeter. Demeter tried to trick him by disguising as a
-horse, but Poseidon saw through the deception and they had Arion.
-
-So Arion is a super fast divine horse; the result of some weird mixing.
-Also it talks.
-
-(And we felt morally obliged to name our stuff after Greek mythology)
--- a/docs/modules/ROOT/pages/options.adoc
+++ b/docs/modules/ROOT/pages/options.adoc
@ -1,3 +0,0 @@
-# Arion Options
-
-include::partial$arion-options.adoc[]
--- a/docs/options.nix
+++ b/docs/options.nix
@ -1,20 +0,0 @@
-{ pkgs ? import ../nix {} }:
-
-let
-  eval = pkgs.lib.evalModules {
-    modules = import ../src/nix/modules.nix;
-  };
-  options = pkgs.nixosOptionsDoc {
-    options = eval.options;
-  };
-
-in (pkgs.runCommand "agent-options.adoc" { } ''
-  cat >$out <<EOF
-  = Arion options
-
-  EOF
-  cat ${options.optionsAsciiDoc} >>$out
-'').overrideAttrs (o: {
-  # Work around https://github.com/hercules-ci/hercules-ci-agent/issues/168
-  allowSubstitutes = true;
-})
--- a/docs/ui-bundle.zip
+++ b/docs/ui-bundle.zip
--- a/examples/flake/arion-compose.nix
+++ b/examples/flake/arion-compose.nix
@ -1,30 +0,0 @@
-{ pkgs, ... }:
-let 
-    sh = pkgs.stdenv.mkDerivation {
-        name = "sh";
-        phases = [ "installPhase" ];
-
-        installPhase = ''
-            mkdir -p "$out"/bin
-            ln -s ${pkgs.bash}/bin/sh "$out"/bin/sh
-        '';
-    };
-in{
-  config.project.name = "webapp";
-  config.services = {
-
-    webserver = {
-      image.contents = [ sh ];
-      service.useHostStore = true;
-      service.command = [ "sh" "-c" ''
-                  cd "$$WEB_ROOT"
-                  ${pkgs.python3}/bin/python -m http.server
-                '' ];
-      service.ports = [
-        "8000:8000" # host:container
-      ];
-      service.environment.WEB_ROOT = "${pkgs.nix.doc}/share/doc/nix/manual";
-      service.stop_signal = "SIGINT";
-    };
-  };
-}
--- a/examples/flake/arion-pkgs.nix
+++ b/examples/flake/arion-pkgs.nix
@ -1,13 +0,0 @@
-let
-  flake = if builtins ? getFlake
-    then (builtins.getFlake (toString ./.)).pkgs
-    else (import flake-compat { src = ./.; }).defaultNix;
-  # NB: this is lazy
-  lock = builtins.fromJSON (builtins.readFile ./flake.lock);
-  inherit (lock.nodes.flake-compat.locked) owner repo rev narHash;
-  flake-compat = builtins.fetchTarball {
-    url = "https://github.com/${owner}/${repo}/archive/${rev}.tar.gz";
-    sha256 = narHash;
-  };
-in
-  flake.pkgs
--- a/examples/flake/flake.lock
+++ b/examples/flake/flake.lock
@ -1,44 +0,0 @@
-{
-  "nodes": {
-    "flake-compat": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1606424373,
-        "narHash": "sha256-oq8d4//CJOrVj+EcOaSXvMebvuTkmBJuT5tzlfewUnQ=",
-        "owner": "edolstra",
-        "repo": "flake-compat",
-        "rev": "99f1c2157fba4bfe6211a321fd0ee43199025dbf",
-        "type": "github"
-      },
-      "original": {
-        "owner": "edolstra",
-        "repo": "flake-compat",
-        "type": "github"
-      }
-    },
-    "nixpkgs": {
-      "locked": {
-        "lastModified": 1618853290,
-        "narHash": "sha256-K4fddnrGOcKL+6CEchRrVmepiwvwvHxB87goqBTI5Bs=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "9a1672105db0eebe8ef59f310397435f2d0298d0",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-20.09",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
-    "root": {
-      "inputs": {
-        "flake-compat": "flake-compat",
-        "nixpkgs": "nixpkgs"
-      }
-    }
-  },
-  "root": "root",
-  "version": 7
-}
--- a/examples/flake/flake.nix
+++ b/examples/flake/flake.nix
@ -1,19 +0,0 @@
-{
-  description = "A very basic flake";
-
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-20.09";
-  inputs.flake-compat.url = "github:edolstra/flake-compat";
-  inputs.flake-compat.flake = false;
-
-  outputs = { self, nixpkgs, ... }: {
-
-    pkgs = nixpkgs.legacyPackages.x86_64-linux;
-    # # alternative:
-    # pkgs = import nixpkgs { config = { }; overlays = [ ]; system = "x86_64-linux"; };
-
-    packages.x86_64-linux.hello = nixpkgs.legacyPackages.x86_64-linux.hello;
-
-    defaultPackage.x86_64-linux = self.packages.x86_64-linux.hello;
-
-  };
-}
--- a/examples/full-nixos/arion-compose.nix
+++ b/examples/full-nixos/arion-compose.nix
@ -1,15 +1,9 @@
 {
-  project.name = "full-nixos";
-  services.webserver = { pkgs, lib, ... }: {
+  docker-compose.services.webserver = { pkgs, ... }: {
    nixos.useSystemd = true;
-    nixos.configuration.boot.tmp.useTmpfs = true;
-    nixos.configuration.networking.useDHCP = false;
+    nixos.configuration.boot.tmpOnTmpfs = true;
    nixos.configuration.services.nginx.enable = true;
    nixos.configuration.services.nginx.virtualHosts.localhost.root = "${pkgs.nix.doc}/share/doc/nix/manual";
-    nixos.configuration.services.nscd.enable = false;
-    nixos.configuration.system.nssModules = lib.mkForce [];
-    nixos.configuration.systemd.services.nginx.serviceConfig.AmbientCapabilities = 
-      lib.mkForce [ "CAP_NET_BIND_SERVICE" ];
    service.useHostStore = true;
    service.ports = [
      "8000:80" # host:container
--- a/examples/full-nixos/arion-pkgs.nix
+++ b/examples/full-nixos/arion-pkgs.nix
@ -1,6 +1,2 @@
 # Instead of pinning Nixpkgs, we can opt to use the one in NIX_PATH
-import <nixpkgs> {
-  # We specify the architecture explicitly. Use a Linux remote builder when
-  # calling arion from other platforms.
-  system = "x86_64-linux";
-}
+import <nixpkgs> {}
--- a/examples/minimal/arion-compose.nix
+++ b/examples/minimal/arion-compose.nix
@ -1,11 +1,10 @@
 { pkgs, ... }:
 {
-  project.name = "webapp";
-  services = {
+  config.docker-compose.services = {

    webserver = {
-      image.enableRecommendedContents = true;
      service.useHostStore = true;
+      # service.depends_on = [ "backend" ];
      service.command = [ "sh" "-c" ''
                  cd "$$WEB_ROOT"
                  ${pkgs.python3}/bin/python -m http.server
@ -14,7 +13,9 @@
        "8000:8000" # host:container
      ];
      service.environment.WEB_ROOT = "${pkgs.nix.doc}/share/doc/nix/manual";
-      service.stop_signal = "SIGINT";
    };
+
+    # backend = { ... }
  };
 }
+    
--- a/examples/minimal/arion-pkgs.nix
+++ b/examples/minimal/arion-pkgs.nix
@ -1,6 +1,2 @@
 # Instead of pinning Nixpkgs, we can opt to use the one in NIX_PATH
-import <nixpkgs> {
-  # We specify the architecture explicitly. Use a Linux remote builder when
-  # calling arion from other platforms.
-  system = "x86_64-linux";
-}
+import <nixpkgs> {}
--- a/examples/nixos-unit/arion-compose.nix
+++ b/examples/nixos-unit/arion-compose.nix
@ -17,27 +17,17 @@
 */

 {
-  project.name = "nixos-unit";
-  services.webserver = { config, pkgs, ... }: {
+  docker-compose.services.webserver = { config, pkgs, ... }: {

-    nixos.configuration = {config, lib, options, pkgs, ...}: {
+    nixos.configuration = {config, pkgs, ...}: {
      boot.isContainer = true;
-      services.nginx = {
-        enable = true;
-        virtualHosts.localhost.root = "${pkgs.nix.doc}/share/doc/nix/manual";
-      } // lib.optionalAttrs (options?services.nginx.stateDir) {
-        # Work around a problem in NixOS 20.03
-        stateDir = "/var/lib/nginx";
-      };
+      services.nginx.enable = true;
+      services.nginx.virtualHosts.localhost.root = "${pkgs.nix.doc}/share/doc/nix/manual";
      system.build.run-nginx = pkgs.writeScript "run-nginx" ''
        #!${pkgs.bash}/bin/bash
        PATH='${config.systemd.services.nginx.environment.PATH}'
        echo nginx:x:${toString config.users.users.nginx.uid}:${toString config.users.groups.nginx.gid}:nginx web server user:/var/empty:/bin/sh >>/etc/passwd
        echo nginx:x:${toString config.users.groups.nginx.gid}:nginx >>/etc/group
-        echo 'nobody:x:65534:65534:Unprivileged account do not use:/var/empty:/run/current-system/sw/bin/nologin' >>/etc/passwd
-        echo 'nogroup:x:65534:' >>/etc/group
-        mkdir -p /var/log/nginx /run/nginx/ /var/cache/nginx /var/lib/nginx/{,logs,proxy_temp,client_body_temp,fastcgi_temp,scgi_temp,uwsgi_temp} /tmp/nginx_client_body
-        chown nginx /var/log/nginx /run/nginx/ /var/cache/nginx /var/lib/nginx/{,logs,proxy_temp,client_body_temp,fastcgi_temp,scgi_temp,uwsgi_temp} /tmp/nginx_client_body
        ${config.systemd.services.nginx.runner}
      '';
    };
--- a/examples/nixos-unit/arion-pkgs.nix
+++ b/examples/nixos-unit/arion-pkgs.nix
@ -1,6 +1,2 @@
 # Instead of pinning Nixpkgs, we can opt to use the one in NIX_PATH
-import <nixpkgs> {
-  # We specify the architecture explicitly. Use a Linux remote builder when
-  # calling arion from other platforms.
-  system = "x86_64-linux";
-}
+import <nixpkgs> {}
--- a/examples/traefik/arion-compose.nix
+++ b/examples/traefik/arion-compose.nix
@ -1,64 +0,0 @@
-/*
- 
-  An example of
-   - traefik HTTP reverse proxy
-   - minimal images
-   - routing via docker labels
-
-  Run `arion up -d` and open http://nix-docs.localhost/
-
- */
-{ lib, pkgs, ... }: {
-  config.project.name = "traefik";
-  config.networks = {
-    traefik-custom = {
-      name = "traefik-custom";
-      ipam = {
-        config = [{
-          subnet = "172.32.0.0/16";
-          gateway = "172.32.0.1";
-        }];
-      };
-    };
-  };
-  config.services = {
-    traefik = {
-      image.command = [
-        "${pkgs.traefik}/bin/traefik"
-        "--api.insecure=true"
-        "--providers.docker=true"
-        "--providers.docker.exposedbydefault=false"
-        "--entrypoints.web.address=:80"
-      ];
-      service = {
-        container_name = "traefik";
-        stop_signal = "SIGINT";
-        ports = [ "80:80" "8080:8080" ];
-        volumes = [ "/var/run/docker.sock:/var/run/docker.sock:ro" ];
-        networks = [ "traefik-custom" ];
-      };
-    };
-
-    nix-docs = {
-      image.command = ["${pkgs.writeScript "entrypoint" ''
-        #!${pkgs.bash}/bin/bash
-        cd ${pkgs.nix.doc}/share/doc/nix/manual
-        ${pkgs.python3}/bin/python -m http.server
-      ''}"];
-      service.container_name = "simple-service";
-      service.stop_signal = "SIGINT";
-      service.labels = {
-        "traefik.enable" = "true";
-        "traefik.http.routers.nix-docs.rule" = "Host(`nix-docs.localhost`)";
-        "traefik.http.routers.nix-docs.entrypoints" = "web";
-        "traefik.http.services.nix-docs.loadBalancer.server.port" = "8000";
-      };
-      service.networks = {
-        traefik-custom = {
-          ipv4_address = "172.32.0.5";
-        };
-      };
-    };
-  };
-}
-
--- a/examples/traefik/arion-pkgs.nix
+++ b/examples/traefik/arion-pkgs.nix
@ -1,6 +0,0 @@
-# Instead of pinning Nixpkgs, we can opt to use the one in NIX_PATH
-import <nixpkgs> {
-  # We specify the architecture explicitly. Use a Linux remote builder when
-  # calling arion from other platforms.
-  system = "x86_64-linux";
-}
--- a/flake.lock
+++ b/flake.lock
@ -1,107 +0,0 @@
-{
-  "nodes": {
-    "flake-parts": {
-      "inputs": {
-        "nixpkgs-lib": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1722555600,
-        "narHash": "sha256-XOQkdLafnb/p9ij77byFQjDf5m5QYl9b2REiVClC+x4=",
-        "owner": "hercules-ci",
-        "repo": "flake-parts",
-        "rev": "8471fe90ad337a8074e957b69ca4d0089218391d",
-        "type": "github"
-      },
-      "original": {
-        "owner": "hercules-ci",
-        "repo": "flake-parts",
-        "type": "github"
-      }
-    },
-    "flake-parts_2": {
-      "inputs": {
-        "nixpkgs-lib": [
-          "hercules-ci-effects",
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1712014858,
-        "narHash": "sha256-sB4SWl2lX95bExY2gMFG5HIzvva5AVMJd4Igm+GpZNw=",
-        "owner": "hercules-ci",
-        "repo": "flake-parts",
-        "rev": "9126214d0a59633752a136528f5f3b9aa8565b7d",
-        "type": "github"
-      },
-      "original": {
-        "id": "flake-parts",
-        "type": "indirect"
-      }
-    },
-    "haskell-flake": {
-      "locked": {
-        "lastModified": 1675296942,
-        "narHash": "sha256-u1X1sblozi5qYEcLp1hxcyo8FfDHnRUVX3dJ/tW19jY=",
-        "owner": "srid",
-        "repo": "haskell-flake",
-        "rev": "c2cafce9d57bfca41794dc3b99c593155006c71e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "srid",
-        "ref": "0.1.0",
-        "repo": "haskell-flake",
-        "type": "github"
-      }
-    },
-    "hercules-ci-effects": {
-      "inputs": {
-        "flake-parts": "flake-parts_2",
-        "nixpkgs": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1719226092,
-        "narHash": "sha256-YNkUMcCUCpnULp40g+svYsaH1RbSEj6s4WdZY/SHe38=",
-        "owner": "hercules-ci",
-        "repo": "hercules-ci-effects",
-        "rev": "11e4b8dc112e2f485d7c97e1cee77f9958f498f5",
-        "type": "github"
-      },
-      "original": {
-        "owner": "hercules-ci",
-        "repo": "hercules-ci-effects",
-        "type": "github"
-      }
-    },
-    "nixpkgs": {
-      "locked": {
-        "lastModified": 1722630782,
-        "narHash": "sha256-hMyG9/WlUi0Ho9VkRrrez7SeNlDzLxalm9FwY7n/Noo=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "d04953086551086b44b6f3c6b7eeb26294f207da",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-unstable",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
-    "root": {
-      "inputs": {
-        "flake-parts": "flake-parts",
-        "haskell-flake": "haskell-flake",
-        "hercules-ci-effects": "hercules-ci-effects",
-        "nixpkgs": "nixpkgs"
-      }
-    }
-  },
-  "root": "root",
-  "version": 7
-}
--- a/flake.nix
+++ b/flake.nix
@ -1,98 +0,0 @@
-{
-  description = "Arion - use Docker Compose via Nix";
-
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
-    haskell-flake.url = "github:srid/haskell-flake/0.1.0";
-    flake-parts.url = "github:hercules-ci/flake-parts";
-    flake-parts.inputs.nixpkgs-lib.follows = "nixpkgs";
-    hercules-ci-effects.url = "github:hercules-ci/hercules-ci-effects";
-    hercules-ci-effects.inputs.nixpkgs.follows = "nixpkgs";
-  };
-
-  outputs = inputs@{ self, flake-parts, ... }:
-    flake-parts.lib.mkFlake { inherit inputs; } ({ config, lib, extendModules, ... }: {
-      imports = [
-        inputs.haskell-flake.flakeModule
-        inputs.hercules-ci-effects.flakeModule
-        inputs.flake-parts.flakeModules.easyOverlay
-        ./docs/flake-module.nix
-        ./tests/flake-module.nix
-      ];
-      systems = inputs.nixpkgs.lib.systems.flakeExposed;
-      perSystem = { config, self', inputs', pkgs, system, final, ... }:
-        let h = pkgs.haskell.lib.compose; in
-        {
-          overlayAttrs = {
-            inherit (config.packages) arion;
-            arionTestingFlags = {
-              dockerSupportsSystemd = false;
-            };
-          };
-          packages.default = config.packages.arion;
-          packages.overlay-test = final.arion;
-          packages.arion = import ./nix/arion.nix { inherit pkgs; };
-          haskellProjects.haskell-package = {
-            # not autodetected: https://github.com/srid/haskell-flake/issues/49
-            packages.arion-compose.root = ./.;
-
-            overrides =
-              self: super: {
-                arion-compose =
-                  lib.pipe super.arion-compose [
-                    (h.addBuildTools [ pkgs.nix ])
-                    (h.overrideCabal (o: {
-                      src = pkgs.lib.sourceByRegex ./. [
-                        ".*[.]cabal"
-                        "LICENSE"
-                        "src/?.*"
-                        "README.asciidoc"
-                        "CHANGELOG.md"
-                      ];
-                      preCheck = ''
-                        export NIX_LOG_DIR=$TMPDIR
-                        export NIX_STATE_DIR=$TMPDIR
-                        export NIX_PATH=nixpkgs=${pkgs.path}
-                      '';
-                    }))
-                  ];
-              };
-          };
-          devShells.default = config.devShells.haskell-package.overrideAttrs (o: {
-            nativeBuildInputs = o.nativeBuildInputs or [ ] ++ [
-              pkgs.docker-compose
-              pkgs.nixpkgs-fmt
-              config.haskellProjects.haskell-package.haskellPackages.releaser
-            ];
-          });
-        };
-
-      hercules-ci.flake-update = {
-        enable = true;
-        autoMergeMethod = "merge";
-        when = {
-          hour = [ 2 ];
-          dayOfMonth = [ 5 ];
-        };
-      };
-
-      herculesCI.ciSystems = [
-        # "aarch64-darwin"
-        # "aarch64-linux"
-        "x86_64-darwin"
-        "x86_64-linux"
-      ];
-
-      flake = {
-        debug = { inherit inputs config lib; };
-
-        lib = {
-          eval = import ./src/nix/eval-composition.nix;
-          build = args@{ ... }:
-            let composition = self.lib.eval args;
-            in composition.config.out.dockerComposeYaml;
-        };
-        nixosModules.arion = ./nixos-module.nix;
-      };
-    });
-}
--- a/13
+++ b/13
@ -1,13 +0,0 @@
-#!/usr/bin/env nix-shell
-#!nix-shell ./shell.nix
-#!nix-shell -i bash
-set -eux -o pipefail
-
-cd "$(dirname "${BASH_SOURCE[0]}")"
-
-ghcid \
-  --command 'cabal v2-repl arion-compose:arion-unit-tests --flags ghci --write-ghc-environment-files=never' \
-  --test=Main.main \
-  --reload=src/haskell \
-  --restart=arion-compose.cabal \
-  ;
--- a/nix/arion.nix
+++ b/nix/arion.nix
@ -1,13 +0,0 @@
-# Like the upstreamable expression but wired up for the local arion.
-{ pkgs ? import ./. {}
-, lib ? pkgs.lib
-, haskell ? pkgs.haskell
-, haskellPackages ? pkgs.haskellPackages
-, arion-compose ? import ./haskell-arion-compose.nix { inherit pkgs haskellPackages; }
-, runCommand ? pkgs.runCommand
-}:
-import ./upstreamable/default.nix {
-  inherit pkgs lib haskell runCommand;
-  haskellPackages = haskellPackages // { inherit arion-compose; };
-  evalSrc = ./..;
-}
--- a/nix/compat.nix
+++ b/nix/compat.nix
@ -1,10 +0,0 @@
-(import
-  (
-    let lock = builtins.fromJSON (builtins.readFile ./flake.lock); in
-    fetchTarball {
-      url = "https://github.com/edolstra/flake-compat/archive/009399224d5e398d03b22badca40a37ac85412a1.tar.gz";
-      sha256 = "sha256:0xcr9fibnapa12ywzcnlf54wrmbqqb96fmmv8043zhsycws7bpqy";
-    }
-  )
-  { src = ../.; }
-).defaultNix
--- a/nix/default.nix
+++ b/nix/default.nix
@ -0,0 +1,13 @@
+/**
+ * This is the entry-point for all nix execution in this project.
+ */
+{ nixpkgsSrc ? ./nixpkgs.nix, ... }:
+import (import ./nixpkgs.nix) {
+  # Makes the config pure as well. See <nixpkgs>/top-level/impure.nix:
+  config = {
+  };
+  overlays = [
+    # all the packages are defined there:
+    (import ./overlay.nix)
+  ];
+}
--- a/nix/haskell-arion-compose.nix
+++ b/nix/haskell-arion-compose.nix
@ -1,20 +0,0 @@
-
-# NOTE: This file produces a haskell library, not the arion package!
-
-{ pkgs ? import ./default.nix {}, haskellPackages ? pkgs.haskellPackages }:
-let
-  inherit (pkgs.haskell.lib) overrideCabal addBuildTools;
-in
-  overrideCabal (addBuildTools (haskellPackages.callCabal2nix "arion-compose" ./.. {}) [pkgs.nix]) (o: o // {
-    src = pkgs.lib.sourceByRegex ../. [
-      ".*[.]cabal"
-      "LICENSE"
-      "src/?.*"
-      "README.asciidoc"
-    ];
-    preCheck = ''
-      export NIX_LOG_DIR=$TMPDIR
-      export NIX_STATE_DIR=$TMPDIR
-      export NIX_PATH=nixpkgs=${pkgs.path}
-    '';
-  })
--- a/nix/nixpkgs.nix
+++ b/nix/nixpkgs.nix
@ -0,0 +1,5 @@
+# to update: $ nix-prefetch-url --unpack url
+builtins.fetchTarball {
+  url = "https://github.com/NixOS/nixpkgs/archive/be445a9074f139d63e704fa82610d25456562c3d.tar.gz";
+  sha256 = "15dc7gdspimavcwyw9nif4s59v79gk18rwsafylffs9m1ld2dxwa";
+}
--- a/nix/overlay.nix
+++ b/nix/overlay.nix
@ -0,0 +1,5 @@
+self: super: {
+  arion = super.callPackage ../arion.nix {};
+  tests = super.callPackage ../tests {};
+  doc = super.callPackage ../doc {};
+}
--- a/nix/upstreamable/default.nix
+++ b/nix/upstreamable/default.nix
@ -1,88 +0,0 @@
-args@
-{ pkgs
-, lib
-, haskellPackages
-, haskell
-, runCommand
-
-  # Allow this expression file to be used more efficiently in situations where
-  # the sources are more readily available. Unpacking haskellPackages.arion-compose.src
-  # is not always the best choice for arion.eval.
-, evalSrc ? null
-}:
-
-let
-
-  /* This derivation builds the arion tool.
-
-     It is based on the arion-compose Haskell package, but adapted and extended to
-       - have the correct name
-       - have a smaller closure size
-       - have functions to use Arion from inside Nix: arion.eval and arion.build
-       - make it self-contained by including docker-compose
-   */
-  arion =
-    justStaticExecutables (
-      overrideCabal
-        arion-compose
-        cabalOverrides
-      );
-
-  inherit (haskell.lib) justStaticExecutables overrideCabal;
-
-  inherit (haskellPackages) arion-compose;
-
-  cabalOverrides = o: {
-    buildTools = (o.buildTools or []) ++ [pkgs.makeWrapper];
-    passthru = (o.passthru or {}) // {
-      inherit eval build;
-    };
-    # Patch away the arion-compose name. Unlike the Haskell library, the program
-    # is called arion (arion was already taken on hackage).
-    pname = "arion";
-    src = arion-compose.src;
-
-    # PYTHONPATH
-    #
-    # We close off the python module search path!
-    #
-    # Accepting directories from the environment into the search path
-    # tends to break things. Docker Compose does not have a plugin
-    # system as far as I can tell, so I don't expect this to break a
-    # feature, but rather to make the program more robustly self-
-    # contained.
-
-    postInstall = ''${o.postInstall or ""}
-      mkdir -p $out/libexec
-      mv $out/bin/arion $out/libexec
-      makeWrapper $out/libexec/arion $out/bin/arion \
-        --unset PYTHONPATH \
-        --prefix PATH : ${lib.makeBinPath [ pkgs.docker-compose ]} \
-        ;
-    '';
-  };
-
-  # Unpacked sources for evaluation by `eval`
-  evalSrc' = args.evalSrc or (runCommand "arion-src" {}
-    "mkdir $out; tar -C $out --strip-components=1 -xf ${arion-compose.src}");
-
-  /* Function for evaluating a composition
-
-     Re-uses this Nixpkgs evaluation instead of `arion-pkgs.nix`.
-
-     Returns the module system's `config` and `options` variables.
-   */
-  eval = args@{...}:
-    import (evalSrc' + "/src/nix/eval-composition.nix")
-      ({ inherit pkgs; } // args);
-
-  /* Function to derivation of the docker compose yaml file
-     NOTE: The output will change: https://github.com/hercules-ci/arion/issues/82
-
-     This function is particularly useful on CI.
-   */
-  build = args@{...}:
-    let composition = eval args;
-    in composition.config.out.dockerComposeYaml;
-
-in arion
--- a/nixos-module.nix
+++ b/nixos-module.nix
@ -1,118 +0,0 @@
-{ config, lib, options, pkgs, ... }:
-let
-  inherit (lib)
-    attrValues
-    mkIf
-    mkOption
-    mkMerge
-    types
-    ;
-
-  cfg = config.virtualisation.arion;
-
-  projectType = types.submoduleWith {
-    modules = [ projectModule ];
-  };
-
-  projectModule = { config, name, ... }: {
-    options = {
-      settings = mkOption {
-        description = ''
-          Arion project definition, otherwise known as arion-compose.nix contents.
-
-          See <link xlink:href="https://docs.hercules-ci.com/arion/options/">https://docs.hercules-ci.com/arion/options/</link>.
-        '';
-        type = arionSettingsType name;
-        visible = "shallow";
-      };
-      _systemd = mkOption { internal = true; };
-      serviceName = mkOption {
-        description = "The name of the Arion project's systemd service";
-        type = types.str;
-        default = "arion-${name}";
-      };
-    };
-    config = {
-      _systemd.services.${config.serviceName} = {
-        wantedBy = [ "multi-user.target" ];
-        after = [ "sockets.target" ];
-
-        path = [
-          cfg.package
-          cfg.docker.client.package
-        ];
-        environment.ARION_PREBUILT = config.settings.out.dockerComposeYaml;
-        script = ''
-          echo 1>&2 "docker compose file: $ARION_PREBUILT"
-          arion --prebuilt-file "$ARION_PREBUILT" up
-        '';
-      };
-    };
-  };
-
-  arionSettingsType = name:
-    (cfg.package.eval { modules = [{ project.name = lib.mkDefault name; }]; }).type or (
-      throw "lib.evalModules did not produce a type. Please upgrade Nixpkgs to nixos-unstable or >=nixos-21.11"
-    );
-
-in
-{
-  disabledModules = [ "virtualisation/arion.nix" ];
-
-  options = {
-    virtualisation.arion = {
-      backend = mkOption {
-        type = types.enum [ "podman-socket" "docker" ];
-        description = ''
-          Which container implementation to use.
-        '';
-      };
-      package = mkOption {
-        type = types.package;
-
-        default = (import ./. { inherit pkgs; }).arion;
-        description = ''
-          Arion package to use. This will provide <literal>arion</literal>
-          executable that starts the project.
-
-          It also must provide the arion <literal>eval</literal> function as
-          an attribute.
-        '';
-      };
-      docker.client.package = mkOption {
-        type = types.package;
-        internal = true;
-      };
-      projects = mkOption {
-        type = types.attrsOf projectType;
-        default = { };
-        description = ''
-          Arion projects to be run as a service.
-        '';
-      };
-    };
-  };
-
-  config = mkIf (cfg.projects != { }) (
-    mkMerge [
-      {
-        systemd = mkMerge (map (p: p._systemd) (attrValues cfg.projects));
-      }
-      (mkIf (cfg.backend == "podman-socket") {
-        virtualisation.docker.enable = false;
-        virtualisation.podman.enable = true;
-        virtualisation.podman.dockerSocket.enable = true;
-        virtualisation.podman.defaultNetwork = 
-          if options?virtualisation.podman.defaultNetwork.settings
-          then { settings.dns_enabled = true; } # since 2023-01 https://github.com/NixOS/nixpkgs/pull/199965
-          else { dnsname.enable = true; }; # compat <2023
-
-        virtualisation.arion.docker.client.package = pkgs.docker-client;
-      })
-      (mkIf (cfg.backend == "docker") {
-        virtualisation.docker.enable = true;
-        virtualisation.arion.docker.client.package = pkgs.docker;
-      })
-    ]
-  );
-}
--- a/6
+++ b/6
@ -1,6 +0,0 @@
-#!/usr/bin/env nix-shell
-#!nix-shell -i bash
-
-# A Haskell REPL for hacking on the Haskell code
-
-cabal new-repl --write-ghc-environment-files=never
--- a/15
+++ b/15
@ -1,15 +0,0 @@
-#!/usr/bin/env nix-shell
-#!nix-shell -i bash
-#!nix-shell ./shell.nix
-
-# For quick manual testing of a hacked arion
-
-# NB: Only works inside the project directory
-
-cabal \
-  new-run \
-  --write-ghc-environment-files=never \
-  :pkg:arion-compose:exe:arion \
-  -- \
-  "$@" \
-  ;
--- a/15
+++ b/15
@ -1,15 +0,0 @@
-#!/usr/bin/env bash
-
-projectRoot="$(dirname ${BASH_SOURCE[0]})"
-resultLink="$projectRoot/result-run-arion-quick"
-
-[[ -e "$resultLink" ]] || {
-  echo 1>&2 "You don't have a prebuilt arion yet; building it."
-  nix-build "$projectRoot" -A arion --out-link "$resultLink"
-}
-
-echo 1>&2 "Note that you will need to rm '$resultLink' to rebuild the arion executable when needed."
-
-export arion_compose_datadir="$projectRoot/src"
-
-exec "$resultLink/bin/arion" "$@"
--- a/6
+++ b/6
@ -1,6 +0,0 @@
-#!/usr/bin/env bash
-
-# For manual testing of a hacked arion built via Nix.
-# Works when called from outside the project directory.
-
-exec nix run -f "$(dirname ${BASH_SOURCE[0]})" arion "$@"
--- a/shell.nix
+++ b/shell.nix
@ -1 +0,0 @@
-(builtins.getFlake ("git+file://" + toString ./.)).devShells.${builtins.currentSystem}.default
--- a/src/arion
+++ b/src/arion
@ -0,0 +1,308 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+export PATH="@path@:$PATH"
+
+nix_dir="@nix_dir@"
+docker_compose_args=()
+files=()
+command="docker-compose"
+pkgs_argument="./arion-pkgs.nix"
+
+debug() {
+    # echo "$@"
+    :
+}
+
+while test $# != 0; do
+    case "$1" in
+        -f|--file)
+            shift
+            files+=("$1")
+            ;;
+        -f*)
+            files+=("${1/#-f/}")
+            ;;
+        --file=*)
+            files+=("${1/#--file=}")
+            ;;
+        --pkgs)
+            shift
+            pkgs_argument="$1"
+            ;;
+        -h|--help|help)
+            command="help"
+            shift
+            break
+            ;;
+        cat)
+            command="$1"
+            shift
+            break
+            ;;
+        repl)
+            command="$1"
+            shift
+            break
+            ;;
+        exec)
+            command="$1"
+            shift
+            break
+            ;;
+        docker-compose)
+            command="docker-compose"
+            shift
+            break
+            ;;
+        *)
+            break
+            ;;
+    esac
+    shift
+done
+
+while test $# != 0; do
+    docker_compose_args+=("$1")
+    shift
+done
+
+case "$command" in
+    help)
+        cat <<EOF
+
+Arion wraps your system's docker-compose, providing a NixOps-like
+experience for simple container deployments.
+
+Usage:
+  arion up|logs|...     - execute docker-compose commands
+  arion cat             - display raw docker-compose.yaml
+  arion config          - validate and display the config file
+  arion repl            - explore the config interactively
+  arion help
+  arion docker-compose help
+  arion docker-compose help up|logs|...
+
+Top-level arion options
+
+  These must be provided before the command.
+
+  --file FILE       Use FILE instead of the default ./arion-compose.nix
+                    Can be specified multiple times for a merged configuration.
+  --pkgs EXPR       Use EXPR instead of ./arion-pkgs.nix to get the
+                    Nixpkgs attrset used for bootstrapping and evaluating
+                    the configuration.
+
+EOF
+        exit 0
+        ;;
+    *)
+        ;;
+esac
+
+if [[ ${#files[@]} == 0 ]]; then
+    files=("./arion-compose.nix")
+fi
+
+
+debug docker_compose_args: "${docker_compose_args[@]}"
+debug files: "${files[@]}"
+
+docker_compose_yaml=.tmp-nix-docker-compose-$$-$RANDOM.yaml
+cleanup() {
+  rm -f $docker_compose_yaml
+}
+trap cleanup EXIT
+
+modules="["
+
+for file in "${files[@]}"; do
+    case "$file" in
+        /*)
+            modules="$modules (/. + $(printf '"%q"' "$file"))"
+            ;;
+        *)
+            modules="$modules (./. + $(printf '"/%q"' "$file"))"
+            ;;
+    esac
+done
+
+modules="$modules ]"
+
+debug modules: "$modules"
+
+old_IFS="$IFS"
+IFS=""
+args=(
+     )
+IFS="$old_IFS"
+for arg in "${args[@]}"; do
+    echo "arg: $arg"
+done
+
+do_eval() {
+  echo 1>&2 "Evaluating configuration..."
+  # read-write-mode is required for import from derivation
+  nix-instantiate \
+    "$nix_dir/eval-composition.nix" \
+    --eval \
+    --read-write-mode \
+    --json \
+    --argstr uid "$UID" \
+    --arg modules "$modules" \
+    --arg pkgs "$pkgs_argument" \
+    --show-trace \
+    --attr 'config.build.dockerComposeYamlText' \
+    | jq -r . >$docker_compose_yaml;
+}
+
+do_build() {
+  echo 1>&2 "Building configuration..."
+  nix-build \
+    "$nix_dir/eval-composition.nix" \
+    --out-link $docker_compose_yaml \
+    --argstr uid "$UID" \
+    --arg modules "$modules" \
+    --arg pkgs "$pkgs_argument" \
+    --show-trace \
+    --attr 'config.build.dockerComposeYaml' \
+    >/dev/null ;
+
+  echo 1>&2 "Ensuring required images are loaded..."
+  jq -r <"$docker_compose_yaml" \
+    '.["x-arion"].images | map("  - " + .imageName + ":" + .imageTag) | join("\n")'
+  eval "$(
+    jq -r '.["docker-compose"]["x-arion"].images as $images
+         | .["existing-images"] as $loaded
+         | $images
+         | map(
+             if $loaded[.imageName + ":" + .imageTag]
+             then ""
+             else "docker load <" + .image + ";" end
+           )
+         | join("\n")
+     ' <<EOF
+{
+  "docker-compose": $(cat $docker_compose_yaml),
+  "existing-images": {
+    $(docker images \
+        --filter "dangling=false" \
+        --format '"{{.Repository}}:{{.Tag}}": true,')
+    "": false
+  }
+}
+EOF
+      )"
+}
+
+
+do_repl() {
+    # nix repl doesn't autocall its <FILES> arguments
+    # so we improvise. We need a file in this directory
+    # to make sure that all paths are as expected :(
+    trap do_repl_cleanup EXIT;
+
+    REPL_TMP=.tmp-repl-$$-$RANDOM
+    cat <<EOF
+Launch a repl for you, using a temporary file: $REPL_TMP.
+
+This loads the configuration from the modules
+  ${files[*]}
+
+To get started:
+
+To see deployment-wide configuration
+  type config. and hit TAB
+To see the services
+  type config.docker-compose.evaluatedServices TAB or ENTER
+To bring the top-level Nixpkgs attributes into scope
+  type :a (config._module.args.pkgs) // { inherit config; }
+
+EOF
+    cat >"$REPL_TMP" <<EOF
+import $nix_dir/eval-composition.nix {
+  uid = "$UID";
+  modules = $modules;
+  pkgs = $pkgs_argument;
+}
+EOF
+
+    nix repl \
+        "$REPL_TMP" \
+        ;
+}
+do_repl_cleanup() {
+    rm -f $REPL_TMP
+}
+
+run_exec() {
+    case "${#docker_compose_args[@]}" in
+        0)
+            echo "As an argument to exec, please specify a service"
+            exit 1
+            ;;
+        1)
+            case "${docker_compose_args[0]}" in
+                -*|--*)
+                    echo "As an argument to exec, please specify a service"
+                    echo "Note that executing the default command currently does not support"
+                    echo "docker-compose options."
+                    # This requires parsing the options, in order to figure out
+                    # which service to invoke.
+                    exit 1
+                    ;;
+                *)
+                    serviceName="${docker_compose_args[0]}"
+                    do_eval
+                    default_args=()
+                    while read arg; do
+                        default_args+=("$arg")
+                    done < <(
+                        jq < "$docker_compose_yaml" \
+                            --arg serviceName "$serviceName" \
+                            -r \
+                            '.["x-arion"].serviceInfo[$serviceName].defaultExec | tostream | .[1] | select(.)'
+                        )
+                    docker-compose -f $docker_compose_yaml exec "$serviceName" "${default_args[@]}"
+                    ;;
+            esac
+            ;;
+        *)
+            do_eval
+            docker-compose -f $docker_compose_yaml exec "${docker_compose_args[@]}"
+            ;;
+    esac
+}
+
+case "$command" in
+    cat)
+        do_eval
+        jq . < "$docker_compose_yaml"
+        ;;
+    repl)
+        do_repl
+        ;;
+    exec)
+        run_exec "$@"
+        ;;
+    docker-compose)
+        if [[ ${#docker_compose_args[@]} != 0
+           && ${docker_compose_args[0]} != "help"
+           && ${docker_compose_args[0]} != "version"
+            ]]; then
+            case "${docker_compose_args[0]}" in
+                help|version)
+                    :
+                    ;;
+                config|down|events|exec|images|kill|logs|pause|port|ps|rm|stop|top|unpause)
+                    do_eval
+                    ;;
+                *)
+                    do_build
+                    ;;
+            esac
+        fi
+        docker-compose -f $docker_compose_yaml "${docker_compose_args[@]}"
+        ;;
+esac
--- a/src/arion-image/Dockerfile
+++ b/src/arion-image/Dockerfile
@ -1,5 +1,3 @@
 FROM scratch
-# scratch itself can't be run.
-
-# This seems like a no-op:
-CMD []
+COPY passwd /etc/passwd
+ADD tarball.tar.gz /
--- a/src/arion-image/passwd
+++ b/src/arion-image/passwd
@ -0,0 +1,2 @@
+root:x:0:0:System administrator:/root:/bin/sh
+nobody:x:65534:65534:Unprivileged account (don't use!):/var/empty:/run/current-system/sw/bin/nologin
--- a/src/arion-image/tarball/bin/sh
+++ b/src/arion-image/tarball/bin/sh
@ -0,0 +1 @@
+/run/system/bin/sh
--- a/src/arion-image/tarball/usr/bin/env
+++ b/src/arion-image/tarball/usr/bin/env
@ -0,0 +1 @@
+/run/system/usr/bin/env
--- a/src/haskell/exe/Main.hs
+++ b/src/haskell/exe/Main.hs
@ -1,324 +0,0 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE ApplicativeDo #-}
-{-# LANGUAGE OverloadedStrings #-}
-
-import Protolude hiding (Down, option)
-
-import           Arion.Nix
-import           Arion.Aeson
-import           Arion.Images (loadImages)
-import qualified Arion.DockerCompose as DockerCompose
-import           Arion.Services (getDefaultExec)
-import           Arion.ExtendedInfo (loadExtendedInfoFromPath, ExtendedInfo(images, projectName))
-
-import Options.Applicative
-import Control.Monad.Fail
-
-import qualified Data.Text as T
-import qualified Data.Text.IO as T
-
-import Data.Aeson(Value)
-
-import System.Posix.User (getRealUserID)
-
-data CommonOptions =
-  CommonOptions
-    { files :: NonEmpty FilePath
-    , pkgs :: Text
-    , nixArgs :: [Text]
-    , prebuiltComposeFile :: Maybe FilePath
-    , noAnsi :: Bool
-    , compatibility :: Bool
-    , logLevel :: Maybe Text
-    }
-  deriving (Show)
-
-newtype DockerComposeArgs =
-  DockerComposeArgs { unDockerComposeArgs :: [Text] }
-
-ensureConfigFile :: [FilePath] -> NonEmpty FilePath
-ensureConfigFile []     = "./arion-compose.nix" :| []
-ensureConfigFile (x:xs) = x :| xs
-
-parseOptions :: Parser CommonOptions
-parseOptions = do
-    files <-
-      ensureConfigFile <$>
-        many (strOption
-               (  short 'f'
-               <> long "file"
-               <> metavar "FILE"
-               <> help "Use FILE instead of the default ./arion-compose.nix. \
-                        \Can be specified multiple times for a merged configuration" ))
-    pkgs <- T.pack <$> strOption
-          (  short 'p'
-          <> long "pkgs"
-          <> metavar "EXPR"
-          <> showDefault
-          <> value "./arion-pkgs.nix"
-          <> help "Use Nix expression EXPR to get the Nixpkgs attrset used for bootstrapping \
-                   \and evaluating the configuration." )
-    showTrace <- flag False True (long "show-trace"
-                    <> help "Causes Nix to print out a stack trace in case of Nix expression evaluation errors. Specify before command.")
-    -- TODO --option support (https://github.com/pcapriotti/optparse-applicative/issues/284)
-    userNixArgs <- many (T.pack <$> strOption (long "nix-arg" <> metavar "ARG" <> help "Pass an extra argument to nix. Example: --nix-arg --option --nix-arg substitute --nix-arg false"))
-    prebuiltComposeFile <- optional $ strOption
-               (  long "prebuilt-file"
-               <> metavar "JSONFILE"
-               <> help "Do not evaluate and use the prebuilt JSONFILE instead. Causes other evaluation-related options to be ignored." )
-    noAnsi <- flag False True (long "no-ansi"
-                    <> help "Avoid ANSI control sequences")
-    compatibility <- flag False True (long "no-ansi"
-                    <> help "If set, Docker Compose will attempt to convert deploy keys in v3 files to their non-Swarm equivalent")
-    logLevel <- optional $ fmap T.pack $ strOption (long "log-level" <> metavar "LEVEL" <> help "Set log level (DEBUG, INFO, WARNING, ERROR, CRITICAL)")
-    pure $
-      let nixArgs = userNixArgs <|> "--show-trace" <$ guard showTrace
-      in CommonOptions{..}
-
-textArgument :: Mod ArgumentFields [Char] -> Parser Text
-textArgument = fmap T.pack . strArgument
-
-parseCommand :: Parser (CommonOptions -> IO ())
-parseCommand =
-  hsubparser
-    (    command "cat" (info (pure runCat) (progDesc "Spit out the docker compose file as JSON" <> fullDesc))
-      <> command "repl" (info (pure runRepl) (progDesc "Start a nix repl for the whole composition" <> fullDesc))
-      <> command "exec" (info (parseExecCommand) (progDesc "Execute a command in a running container" <> fullDesc))
-    )
-  <|>
-  hsubparser
-    (    commandDC runBuildAndDC "build" "Build or rebuild services"
-      <> commandDC runBuildAndDC "bundle" "Generate a Docker bundle from the Compose file"
-      <> commandDC runEvalAndDC "config" "Validate and view the Compose file"
-      <> commandDC runBuildAndDC "create" "Create services"
-      <> commandDC runEvalAndDC "down" "Stop and remove containers, networks, images, and volumes"
-      <> commandDC runEvalAndDC "events" "Receive real time events from containers"
-      <> commandDC runDC "help" "Get help on a command"
-      <> commandDC runEvalAndDC "images" "List images"
-      <> commandDC runEvalAndDC "kill" "Kill containers"
-      <> commandDC runEvalAndDC "logs" "View output from containers"
-      <> commandDC runEvalAndDC "pause" "Pause services"
-      <> commandDC runEvalAndDC "port" "Print the public port for a port binding"
-      <> commandDC runEvalAndDC "ps" "List containers"
-      <> commandDC runBuildAndDC "pull" "Pull service images"
-      <> commandDC runBuildAndDC "push" "Push service images"
-      <> commandDC runBuildAndDC "restart" "Restart services"
-      <> commandDC runEvalAndDC "rm" "Remove stopped containers"
-      <> commandDC runBuildAndDC "run" "Run a one-off command"
-      <> commandDC runBuildAndDC "scale" "Set number of containers for a service"
-      <> commandDC runBuildAndDC "start" "Start services"
-      <> commandDC runEvalAndDC "stop" "Stop services"
-      <> commandDC runEvalAndDC "top" "Display the running processes"
-      <> commandDC runEvalAndDC "unpause" "Unpause services"
-      <> commandDC runBuildAndDC "up" "Create and start containers"
-      <> commandDC runDC "version" "Show the Docker-Compose version information"
-
-      <> metavar "DOCKER-COMPOSE-COMMAND"
-      <> commandGroup "Docker Compose Commands:"
-    )
-
-parseAll :: Parser (IO ())
-parseAll =
-  flip ($) <$> parseOptions <*> parseCommand
-
-parseDockerComposeArgs :: Parser DockerComposeArgs
-parseDockerComposeArgs =
-  DockerComposeArgs <$>
-    many (argument (T.pack <$> str) (metavar "DOCKER-COMPOSE ARGS..."))
-
-commandDC
-  :: (Text -> DockerComposeArgs -> CommonOptions -> IO ())
-  -> Text
-  -> Text
-  -> Mod CommandFields (CommonOptions -> IO ())
-commandDC run cmdStr helpText =
-  command
-    (T.unpack cmdStr)
-    (info
-      (run cmdStr <$> parseDockerComposeArgs)
-      (progDesc (T.unpack helpText) <> fullDesc <> forwardOptions))
-
-
--------------------------------------------------------------------------------
-
-runDC :: Text -> DockerComposeArgs -> CommonOptions -> IO ()
-runDC cmd (DockerComposeArgs args) _opts = do
-  DockerCompose.run DockerCompose.Args
-    { files = []
-    , otherArgs = [cmd] ++ args
-    }
-
-runBuildAndDC :: Text -> DockerComposeArgs -> CommonOptions -> IO ()
-runBuildAndDC cmd dopts opts = do
-  withBuiltComposeFile opts $ callDC cmd dopts opts True
-
-runEvalAndDC :: Text -> DockerComposeArgs -> CommonOptions -> IO ()
-runEvalAndDC cmd dopts opts = do
-  withComposeFile opts $ callDC cmd dopts opts False
-
-callDC :: Text -> DockerComposeArgs -> CommonOptions -> Bool -> FilePath -> IO ()
-callDC cmd dopts opts shouldLoadImages path = do
-  extendedInfo <- loadExtendedInfoFromPath path
-  when shouldLoadImages $ loadImages (images extendedInfo)
-  let firstOpts = projectArgs extendedInfo <> commonArgs opts
-  DockerCompose.run DockerCompose.Args
-    { files = [path]
-    , otherArgs = firstOpts ++ [cmd] ++ unDockerComposeArgs dopts
-    }
-
-projectArgs :: ExtendedInfo -> [Text]
-projectArgs extendedInfo =
-  do
-    n <- toList (projectName extendedInfo)
-    ["--project-name", n]
-
-commonArgs :: CommonOptions -> [Text]
-commonArgs opts = do
-    guard (noAnsi opts)
-    ["--no-ansi"]
-  <> do
-    guard (compatibility opts)
-    ["--compatibility"]
-  <> do
-    l <- toList (logLevel opts)
-    ["--log-level", l]
-
-withBuiltComposeFile :: CommonOptions -> (FilePath -> IO r) -> IO r
-withBuiltComposeFile opts cont = case prebuiltComposeFile opts of
-  Just prebuilt -> do
-    cont prebuilt
-  Nothing -> do
-    args <- defaultEvaluationArgs opts
-    Arion.Nix.withBuiltComposition args cont
-
-withComposeFile :: CommonOptions -> (FilePath -> IO r) -> IO r
-withComposeFile opts cont = case prebuiltComposeFile opts of
-  Just prebuilt -> do
-    cont prebuilt
-  Nothing -> do
-    args <- defaultEvaluationArgs opts
-    Arion.Nix.withEvaluatedComposition args cont
-
-getComposeValue :: CommonOptions -> IO Value
-getComposeValue opts = case prebuiltComposeFile opts of
-  Just prebuilt -> do
-    decodeFile prebuilt
-  Nothing -> do
-    args <- defaultEvaluationArgs opts
-    Arion.Nix.evaluateComposition args
-
-defaultEvaluationArgs :: CommonOptions -> IO EvaluationArgs
-defaultEvaluationArgs co = do
-  uid <- getRealUserID
-  pure EvaluationArgs
-    { evalUid = fromIntegral uid
-    , evalModules = files co
-    , evalPkgs = pkgs co
-    , evalWorkDir = Nothing
-    , evalMode = ReadWrite
-    , evalUserArgs = nixArgs co
-    }
-
-runCat :: CommonOptions -> IO ()
-runCat co = do
-  v <- getComposeValue co
-  T.hPutStrLn stdout (pretty v)
-
-runRepl :: CommonOptions -> IO ()
-runRepl co = do
-  putErrText
-    "Launching a repl for you. To get started:\n\
-    \\n\
-    \To see deployment-wide configuration\n\
-    \  type config. and use tab completion\n\
-    \To bring the top-level Nixpkgs attributes into scope\n\
-    \  type :a (config._module.args.pkgs) // { inherit config; }\n\
-    \"
-  Arion.Nix.replForComposition =<< defaultEvaluationArgs co
-
-detachFlag :: Parser Bool
-detachFlag = flag False True (long "detach" <> short 'd' <> help "Detached mode: Run command in the background.")
-
-privilegedFlag :: Parser Bool
-privilegedFlag = flag False True (long "privileged" <> help "Give extended privileges to the process.")
-
-userOption :: Parser Text
-userOption = strOption (long "user" <> short 'u' <> help "Run the command as this user.")
-
-noTTYFlag :: Parser Bool
-noTTYFlag = flag False True (short 'T' <> help "Disable pseudo-tty allocation. By default `exec` allocates a TTY.")
-
-indexOption :: Parser Int
-indexOption = option
-  (auto >>= \i -> i <$ unless (i >= 1) (fail "container index must be >= 1"))
-  (long "index" <> value 1 <> help "Index of the container if there are multiple instances of a service.")
-
-envOption :: Parser (Text, Text)
-envOption = option (auto >>= spl) (long "env" <> short 'e' <> help "Set environment variables (can be used multiple times, not supported in Docker API < 1.25)")
-  where spl s = case T.break (== '=') s of
-          (_, "") -> fail "--env parameter needs to combine key and value with = sign"
-          (k, ev) -> pure (k, T.drop 1 ev)
-
-workdirOption :: Parser Text
-workdirOption = strOption (long "workdir" <> short 'w' <> metavar "DIR" <> help "Working directory in which to start the command in the container.")
-
-parseExecCommand :: Parser (CommonOptions -> IO ())
-parseExecCommand = runExec
-  <$> detachFlag
-  <*> privilegedFlag
-  <*> optional userOption
-  <*> noTTYFlag
-  <*> indexOption
-  <*> many envOption
-  <*> optional workdirOption
-  <*> textArgument (metavar "SERVICE")
-  <*> orEmpty' (
-      (:) <$> argument (T.pack <$> str) (metavar "COMMAND")
-          <*> many (argument (T.pack <$> str) (metavar "ARG"))
-  )
-
-orEmpty' :: (Alternative f, Monoid a) => f a -> f a
-orEmpty' m = fromMaybe mempty <$> optional m
-
-runExec :: Bool -> Bool -> Maybe Text -> Bool -> Int -> [(Text, Text)] -> Maybe Text -> Text -> [Text] -> CommonOptions -> IO ()
-runExec detach privileged user noTTY index envs workDir service commandAndArgs opts =
-  withComposeFile opts $ \path -> do
-    extendedInfo <- loadExtendedInfoFromPath path
-    commandAndArgs'' <- case commandAndArgs of
-      [] -> do
-        cmd <- getDefaultExec path service
-        case cmd of
-          [] -> do
-            putErrText "You must provide a command via service.defaultExec or on the command line."
-            exitFailure
-          _ ->
-            pure cmd
-      x -> pure x
-    let commandAndArgs' = case commandAndArgs'' of
-          [] -> ["/bin/sh"]
-          x -> x
-  
-    let args = concat
-          [ ["exec"]
-          , ("--detach" <$ guard detach :: [Text])
-          , "--privileged" <$ guard privileged
-          , "-T" <$ guard noTTY
-          , (\(k, v) -> ["--env", k <> "=" <> v]) =<< envs
-          , join $ toList (user <&> \u -> ["--user", u])
-          , ["--index", show index]
-          , join $ toList (workDir <&> \w -> ["--workdir", w])
-          , [service]
-          , commandAndArgs'
-          ]
-    DockerCompose.run DockerCompose.Args
-      { files = [path]
-      , otherArgs = projectArgs extendedInfo <> commonArgs opts <> args
-      }
-
-main :: IO ()
-main = 
-  (join . arionExecParser) (info (parseAll <**> helper) fullDesc)
-  where
-    arionExecParser = customExecParser (prefs showHelpOnEmpty)
-
--- a/src/haskell/lib/Arion/Aeson.hs
+++ b/src/haskell/lib/Arion/Aeson.hs
@ -1,27 +0,0 @@
-module Arion.Aeson where
-
-import Prelude ()
-import           Data.Aeson
-import qualified Data.ByteString.Lazy          as BL
-import qualified Data.Text.Lazy                as TL
-import qualified Data.Text.Lazy.Builder        as TB
-import qualified Data.Aeson.Encode.Pretty
-import           Data.Aeson.Encode.Pretty       ( defConfig
-                                                , confCompare
-                                                , confTrailingNewline
-                                                )
-import           Protolude
-
-pretty :: ToJSON a => a -> Text
-pretty =
-  TL.toStrict
-    . TB.toLazyText
-    . Data.Aeson.Encode.Pretty.encodePrettyToTextBuilder' config
-  where config = defConfig { confCompare = compare, confTrailingNewline = True }
-
-decodeFile :: FromJSON a => FilePath -> IO a
-decodeFile fp = do
-  b <- BL.readFile fp
-  case eitherDecode b of
-    Left e -> panic (toS e)
-    Right v -> pure v
--- a/src/haskell/lib/Arion/DockerCompose.hs
+++ b/src/haskell/lib/Arion/DockerCompose.hs
@ -1,30 +0,0 @@
-{-# LANGUAGE OverloadedStrings #-}
-module Arion.DockerCompose where
-
-import           Prelude                        ( )
-import           Protolude
-import           System.Process
-
-data Args = Args
-  { files :: [FilePath]
-  , otherArgs :: [Text]
-  }
-
-run :: Args -> IO ()
-run args = do
-  let fileArgs = files args >>= \f -> ["--file", f]
-      allArgs  = fileArgs ++ map toS (otherArgs args)
-
-      procSpec = proc "docker-compose" allArgs
-
-  -- hPutStrLn stderr ("Running docker-compose with " <> show allArgs :: Text)
-
-  withCreateProcess procSpec $ \_in _out _err procHandle -> do
-
-    exitCode <- waitForProcess procHandle
-
-    case exitCode of
-      ExitSuccess -> pass
-      ExitFailure 1 -> exitFailure
-      ExitFailure {} -> do
-        throwIO $ FatalError $ "docker-compose failed with " <> show exitCode
--- a/src/haskell/lib/Arion/ExtendedInfo.hs
+++ b/src/haskell/lib/Arion/ExtendedInfo.hs
@ -1,37 +0,0 @@
-{-# LANGUAGE DeriveAnyClass #-}
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-
-
-Parses the x-arion field in the generated compose file.
-
-}
-module Arion.ExtendedInfo where
-
-import Prelude()
-import Protolude
-import Data.Aeson as Aeson
-import Arion.Aeson
-import Control.Lens
-import Data.Aeson.Lens
-
-data Image = Image
-  { image :: Maybe Text -- ^ image tar.gz file path
-  , imageExe :: Maybe Text -- ^ path to exe producing image tar
-  , imageName :: Text
-  , imageTag :: Text
-  } deriving (Eq, Show, Generic, Aeson.ToJSON, Aeson.FromJSON)
-
-data ExtendedInfo = ExtendedInfo {
-    projectName :: Maybe Text,
-    images :: [Image]
-  } deriving (Eq, Show)
-
-loadExtendedInfoFromPath :: FilePath -> IO ExtendedInfo
-loadExtendedInfoFromPath fp = do
-  v <- decodeFile fp
-  pure ExtendedInfo {
-    -- TODO: use aeson derived instance?
-    projectName = v ^? key "x-arion" . key "project" . key "name" . _String,
-    images = (v :: Aeson.Value) ^.. key "x-arion" . key "images" . _Array . traverse . _JSON
-  }
--- a/src/haskell/lib/Arion/Images.hs
+++ b/src/haskell/lib/Arion/Images.hs
@ -1,72 +0,0 @@
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE DeriveAnyClass #-}
-{-# LANGUAGE OverloadedStrings #-}
-module Arion.Images
-  ( loadImages
-  ) where
-
-import Prelude()
-import Protolude hiding (to)
-
-import qualified System.Process as Process
-import qualified Data.Text as T
-
-import Arion.ExtendedInfo (Image(..))
-
-type TaggedImage = Text
-
-- | Subject to change
-loadImages :: [Image] -> IO ()
-loadImages requestedImages = do
-
-  loaded <- getDockerImages
-
-  let
-    isNew i =
-      -- On docker, the image name is unmodified
-      (imageName i <> ":" <> imageTag i) `notElem` loaded
-      -- On podman, you used to automatically get a localhost prefix
-      -- however, since NixOS 22.05, this expected to be part of the name instead
-        && ("localhost/" <> imageName i <> ":" <> imageTag i) `notElem` loaded
-
-  traverse_ loadImage . filter isNew $ requestedImages
-
-loadImage :: Image -> IO ()
-loadImage Image { image = Just imgPath, imageName = name } =
-  withFile (toS imgPath) ReadMode $ \fileHandle -> do
-  let procSpec = (Process.proc "docker" [ "load" ]) {
-          Process.std_in = Process.UseHandle fileHandle
-        }
-  Process.withCreateProcess procSpec $ \_in _out _err procHandle -> do
-    e <- Process.waitForProcess procHandle
-    case e of
-      ExitSuccess -> pass
-      ExitFailure code ->
-        panic $ "docker load failed with exit code " <> show code <> " for image " <> name <> " from path " <> imgPath
-
-loadImage Image { imageExe = Just imgExe, imageName = name } = do
-  let loadSpec = (Process.proc "docker" [ "load" ]) { Process.std_in = Process.CreatePipe }
-  Process.withCreateProcess loadSpec $ \(Just inHandle) _out _err loadProcHandle -> do
-    let streamSpec = Process.proc (toS imgExe) []
-    Process.withCreateProcess streamSpec { Process.std_out = Process.UseHandle inHandle } $ \_ _ _ streamProcHandle ->
-      withAsync (Process.waitForProcess loadProcHandle) $ \loadExitAsync ->
-        withAsync (Process.waitForProcess streamProcHandle) $ \streamExitAsync -> do
-          r <- waitEither loadExitAsync streamExitAsync
-          case r of
-            Right (ExitFailure code) -> panic $ "image producer for image " <> name <> " failed with exit code " <> show code <> " from executable " <> imgExe
-            Right ExitSuccess -> pass
-            Left _ -> pass
-          loadExit <- wait loadExitAsync
-          case loadExit of
-            ExitFailure code -> panic $ "docker load failed with exit code " <> show code <> " for image " <> name <> " produced by executable " <> imgExe
-            _ -> pass
-          pass
-
-loadImage Image { imageName = name } = do
-  panic $ "image " <> name <> " doesn't specify an image file or imageExe executable"
-
-
-getDockerImages :: IO [TaggedImage]
-getDockerImages = do
-  let procSpec = Process.proc "docker" [ "images",  "--filter", "dangling=false", "--format", "{{.Repository}}:{{.Tag}}" ]
-  map toS . T.lines . toS <$> Process.readCreateProcess procSpec ""
--- a/src/haskell/lib/Arion/Nix.hs
+++ b/src/haskell/lib/Arion/Nix.hs
@ -1,183 +0,0 @@
-{-# LANGUAGE OverloadedStrings #-}
-module Arion.Nix
-  ( evaluateComposition
-  , withEvaluatedComposition
-  , buildComposition
-  , withBuiltComposition
-  , replForComposition
-  , EvaluationArgs(..)
-  , EvaluationMode(..)
-  ) where
-
-import           Prelude                        ( )
-import           Protolude
-import           Arion.Aeson                    ( pretty )
-import           Data.Aeson
-import qualified Data.String
-import qualified System.Directory              as Directory
-import           System.Process
-import qualified Data.ByteString.Lazy          as BL
-import           Paths_arion_compose
-
-import qualified Data.Text.IO                  as T
-
-import qualified Data.List.NonEmpty            as NE
-
-import           Control.Arrow                  ( (>>>) )
-import           System.IO.Temp                 ( withTempFile )
-import           System.IO                      ( hClose )
-
-data EvaluationMode =
-  ReadWrite | ReadOnly
-
-data EvaluationArgs = EvaluationArgs
- { evalUid :: Int
- , evalModules :: NonEmpty FilePath
- , evalPkgs :: Text
- , evalWorkDir :: Maybe FilePath
- , evalMode :: EvaluationMode
- , evalUserArgs :: [Text]
- }
-
-evaluateComposition :: EvaluationArgs -> IO Value
-evaluateComposition ea = do
-  evalComposition <- getEvalCompositionFile
-  let commandArgs =
-        [ "--eval"
-        , "--strict"
-        , "--json"
-        , "--attr"
-        , "config.out.dockerComposeYamlAttrs"
-        ]
-      args =
-        [ evalComposition ]
-        ++ commandArgs
-        ++ modeArguments (evalMode ea)
-        ++ argArgs ea
-        ++ map toS (evalUserArgs ea)
-      procSpec = (proc "nix-instantiate" args)
-        { cwd = evalWorkDir ea
-        , std_out = CreatePipe
-        }
-  
-  withCreateProcess procSpec $ \_in outHM _err procHandle -> do
-    let outHandle = fromMaybe (panic "stdout missing") outHM
-
-    out <- BL.hGetContents outHandle
-
-    v <- Protolude.evaluate (eitherDecode out)
-
-    exitCode <- waitForProcess procHandle
-
-    case exitCode of
-      ExitSuccess -> pass
-      ExitFailure 1 -> exitFailure
-      ExitFailure {} -> do
-        throwIO $ FatalError $ "evaluation failed with " <> show exitCode
-
-    case v of
-      Right r -> pure r
-      Left  e -> throwIO $ FatalError ("Couldn't parse nix-instantiate output" <> show e)
-
-- | Run with docker-compose.yaml tmpfile
-withEvaluatedComposition :: EvaluationArgs -> (FilePath -> IO r) -> IO r
-withEvaluatedComposition ea f = do
-  v <- evaluateComposition ea
-  withTempFile "." ".tmp-arion-docker-compose.yaml" $ \path yamlHandle -> do
-    T.hPutStrLn yamlHandle (pretty v)
-    hClose yamlHandle
-    f path
-
-
-buildComposition :: FilePath -> EvaluationArgs -> IO ()
-buildComposition outLink ea = do
-  evalComposition <- getEvalCompositionFile
-  let commandArgs =
-        [ "--attr"
-        , "config.out.dockerComposeYaml"
-        , "--out-link"
-        , outLink
-        ]
-      args =
-        [ evalComposition ]
-        ++ commandArgs
-        ++ argArgs ea
-        ++ map toS (evalUserArgs ea)
-      procSpec = (proc "nix-build" args) { cwd = evalWorkDir ea }
-  
-  withCreateProcess procSpec $ \_in _out _err procHandle -> do
-
-    exitCode <- waitForProcess procHandle
-
-    case exitCode of
-      ExitSuccess -> pass
-      ExitFailure 1 -> exitFailure
-      ExitFailure {} -> do
-        throwIO $ FatalError $ "nix-build failed with " <> show exitCode
-
-- | Do something with a docker-compose.yaml.
-withBuiltComposition :: EvaluationArgs -> (FilePath -> IO r) -> IO r
-withBuiltComposition ea f = do
-  withTempFile "." ".tmp-arion-docker-compose.yaml" $ \path emptyYamlHandle -> do
-    hClose emptyYamlHandle
-    -- Known problem: kills atomicity of withTempFile; won't fix because we should manage gc roots,
-    -- impl of which will probably avoid this "problem". It seems unlikely to cause issues.
-    Directory.removeFile path
-    buildComposition path ea
-    f path
-
-
-replForComposition :: EvaluationArgs -> IO ()
-replForComposition ea = do
-    evalComposition <- getEvalCompositionFile
-    let args =
-          [ "repl", evalComposition ]
-          ++ argArgs ea
-          ++ map toS (evalUserArgs ea)
-        procSpec = (proc "nix" args) { cwd = evalWorkDir ea }
-    
-    withCreateProcess procSpec $ \_in _out _err procHandle -> do
-
-      exitCode <- waitForProcess procHandle
-
-      case exitCode of
-        ExitSuccess -> pass
-        ExitFailure 1 -> exitFailure
-        ExitFailure {} -> do
-          throwIO $ FatalError $ "nix repl failed with " <> show exitCode
-
-argArgs :: EvaluationArgs -> [[Char]]
-argArgs ea =
-      [ "--argstr"
-      , "uid"
-      , show $ evalUid ea
-      , "--arg"
-      , "modules"
-      , modulesNixExpr $ evalModules ea
-      , "--arg"
-      , "pkgs"
-      , toS $ evalPkgs ea
-      ]
-
-getEvalCompositionFile :: IO FilePath
-getEvalCompositionFile = getDataFileName "nix/eval-composition.nix"
-
-modeArguments :: EvaluationMode -> [[Char]]
-modeArguments ReadWrite = [ "--read-write-mode" ]
-modeArguments ReadOnly = [ "--readonly-mode" ]
-
-modulesNixExpr :: NonEmpty FilePath -> [Char]
-modulesNixExpr =
-  NE.toList >>> fmap pathExpr >>> Data.String.unwords >>> wrapList
- where
-  pathExpr :: FilePath -> [Char]
-  pathExpr path | isAbsolute path = "(/. + \"/${" <> toNixStringLiteral path <> "}\")"
-                | otherwise       = "(./. + \"/${" <> toNixStringLiteral path <> "}\")"
-
-  isAbsolute ('/' : _) = True
-  isAbsolute _         = False
-
-  wrapList s = "[ " <> s <> " ]"
-
-toNixStringLiteral :: [Char] -> [Char]
-toNixStringLiteral = show -- FIXME: custom escaping including '$'
--- a/src/haskell/lib/Arion/Services.hs
+++ b/src/haskell/lib/Arion/Services.hs
@ -1,37 +0,0 @@
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE DeriveAnyClass #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE CPP #-}
-module Arion.Services
-  ( getDefaultExec
-  ) where
-
-import Prelude()
-import Protolude hiding (to)
-
-import qualified Data.Aeson as Aeson
-#if MIN_VERSION_lens_aeson(1,2,0)
-import qualified Data.Aeson.Key as AK
-#endif
-import           Arion.Aeson (decodeFile)
-
-import Control.Lens
-import Data.Aeson.Lens
-
-#if MIN_VERSION_lens_aeson(1,2,0)
-type Key = AK.Key
-mkKey :: Text -> Key
-mkKey = AK.fromText
-#else
-type Key = Text
-mkKey :: Text -> Key
-mkKey = identity
-#endif
-
-- | Subject to change
-getDefaultExec :: FilePath -> Text -> IO [Text]
-getDefaultExec fp service = do
-
-  v <- decodeFile fp
-
-  pure ((v :: Aeson.Value) ^.. key "x-arion" . key "serviceInfo" . key (mkKey service) . key "defaultExec" . _Array . traverse . _String)
--- a/src/haskell/test/Arion/NixSpec.hs
+++ b/src/haskell/test/Arion/NixSpec.hs
@ -1,74 +0,0 @@
-{-# LANGUAGE OverloadedStrings #-}
-module Arion.NixSpec
-  ( spec
-  )
-where
-
-import           Protolude
-import           Test.Hspec
-import qualified Data.List.NonEmpty            as NEL
-import           Arion.Aeson
-import           Arion.Nix
-import qualified Data.Text                     as T
-import qualified Data.Text.IO                  as T
-
-spec :: Spec
-spec = describe "evaluateComposition" $ do
-  it "matches an example" $ do
-    x <- Arion.Nix.evaluateComposition EvaluationArgs
-      { evalUid      = 123
-      , evalModules  = NEL.fromList
-                         ["src/haskell/testdata/Arion/NixSpec/arion-compose.nix"]
-      , evalPkgs     = "import <nixpkgs> { system = \"x86_64-linux\"; }"
-      , evalWorkDir  = Nothing
-      , evalMode     = ReadOnly
-      , evalUserArgs = ["--show-trace"]
-      }
-    let actual = pretty x
-    expected <- T.readFile "src/haskell/testdata/Arion/NixSpec/arion-compose.json"
-    censorPaths actual `shouldBe` censorPaths expected
-
-  it "matches an build.context example" $ do
-    x <- Arion.Nix.evaluateComposition EvaluationArgs
-      { evalUid      = 1234
-      , evalModules  = NEL.fromList
-                         ["src/haskell/testdata/Arion/NixSpec/arion-context-compose.nix"]
-      , evalPkgs     = "import <nixpkgs> { system = \"x86_64-linux\"; }"
-      , evalWorkDir  = Nothing
-      , evalMode     = ReadOnly
-      , evalUserArgs = ["--show-trace"]
-      }
-    let actual = pretty x
-    expected <- T.readFile "src/haskell/testdata/Arion/NixSpec/arion-context-compose.json"
-    censorPaths actual `shouldBe` censorPaths expected
-
-censorPaths :: Text -> Text
-censorPaths = censorImages . censorStorePaths
-
-censorStorePaths :: Text -> Text
-censorStorePaths x = case T.breakOn "/nix/store/" x of
-  (prefix, tl) | (tl :: Text) == "" -> prefix
-  (prefix, tl) -> prefix <> "<STOREPATH>" <> censorPaths
-    (T.dropWhile isNixNameChar $ T.drop (T.length "/nix/store/") tl)
-
-- Probably slow, due to not O(1) <>
-censorImages :: Text -> Text
-censorImages x = case T.break (\c -> c == ':' || c == '"') x of
-  (prefix, tl) | tl == "" -> prefix
-  (prefix, tl) | let imageId = T.take 33 (T.drop 1 tl)
-               , T.last imageId == '\"'
-                 -- Approximation of nix hash validation
-               , T.all (\c -> (c >= '0' && c <= '9') || (c >= 'a' && c <= 'z')) (T.take 32 imageId)
-               -> prefix <> T.take 1 tl <> "<HASH>" <> censorImages (T.drop 33 tl)
-  (prefix, tl) -> prefix <> T.take 1 tl <> censorImages (T.drop 1 tl)
-
-
-- | WARNING: THIS IS LIKELY WRONG: DON'T REUSE
-isNixNameChar :: Char -> Bool
-isNixNameChar c | c >= '0' && c <= '9' = True
-isNixNameChar c | c >= 'a' && c <= 'z' = True
-isNixNameChar c | c >= 'A' && c <= 'Z' = True
-isNixNameChar c | c == '-' = True
-isNixNameChar c | c == '.' = True
-isNixNameChar c | c == '_' = True -- WRONG?
-isNixNameChar _ = False -- WRONG?
--- a/src/haskell/test/Spec.hs
+++ b/src/haskell/test/Spec.hs
@ -1,12 +0,0 @@
-module Spec
-  ( spec
-  )
-where
-
-import           Test.Hspec
-import qualified Arion.NixSpec
-
-spec :: Spec
-spec = do
-  describe "Arion.Nix" Arion.NixSpec.spec
-
--- a/src/haskell/test/TestMain.hs
+++ b/src/haskell/test/TestMain.hs
@ -1,10 +0,0 @@
-module Main where
-
-import           Prelude()
-import           Protolude
-import           Test.Hspec.Runner
-import qualified Spec
-
-main :: IO ()
-main = hspecWith config Spec.spec
-  where config = defaultConfig { configColorMode = ColorAlways }
--- a/src/haskell/testdata/Arion/NixSpec/arion-compose.json
+++ b/src/haskell/testdata/Arion/NixSpec/arion-compose.json
@ -1,57 +0,0 @@
-{
-    "networks": {
-        "default": {
-            "name": "unit-test-data"
-        }
-    },
-    "services": {
-        "webserver": {
-            "command": [
-                "/usr/sbin/init"
-            ],
-            "environment": {
-                "NIX_REMOTE": "",
-                "PATH": "/usr/bin:/run/current-system/sw/bin/",
-                "container": "docker"
-            },
-            "image": "localhost/webserver:<HASH>",
-            "ports": [
-                "8000:80"
-            ],
-            "stop_signal": "SIGRTMIN+3",
-            "sysctls": {},
-            "tmpfs": [
-                "/run",
-                "/run/wrappers",
-                "/tmp:exec,mode=777"
-            ],
-            "tty": true,
-            "volumes": [
-                "/sys/fs/cgroup:/sys/fs/cgroup:ro",
-                "/nix/store:/nix/store:ro"
-            ]
-        }
-    },
-    "version": "3.4",
-    "volumes": {},
-    "x-arion": {
-        "images": [
-            {
-                "imageExe": "<STOREPATH>",
-                "imageName": "localhost/webserver",
-                "imageTag": "<HASH>"
-            }
-        ],
-        "project": {
-            "name": "unit-test-data"
-        },
-        "serviceInfo": {
-            "webserver": {
-                "defaultExec": [
-                    "/run/current-system/sw/bin/bash",
-                    "-l"
-                ]
-            }
-        }
-    }
-}
--- a/src/haskell/testdata/Arion/NixSpec/arion-compose.nix
+++ b/src/haskell/testdata/Arion/NixSpec/arion-compose.nix
@ -1,13 +0,0 @@
-{
-  project.name = "unit-test-data";
-  services.webserver = { pkgs, ... }: {
-    nixos.useSystemd = true;
-    nixos.configuration.boot.tmp.useTmpfs = true;
-    nixos.configuration.services.nginx.enable = true;
-    nixos.configuration.services.nginx.virtualHosts.localhost.root = "${pkgs.nix.doc}/share/doc/nix/manual";
-    service.useHostStore = true;
-    service.ports = [
-      "8000:80" # host:container
-    ];
-  };
-}
--- a/src/haskell/testdata/Arion/NixSpec/arion-context-compose.json
+++ b/src/haskell/testdata/Arion/NixSpec/arion-context-compose.json
@ -1,41 +0,0 @@
-{
-    "networks": {
-        "default": {
-            "name": "unit-test-data"
-        }
-    },
-    "services": {
-        "webserver": {
-            "build": {
-                "context": "<STOREPATH>"
-            },
-            "environment": {},
-            "ports": [
-                "8080:80"
-            ],
-            "sysctls": {},
-            "volumes": []
-        }
-    },
-    "version": "3.4",
-    "volumes": {},
-    "x-arion": {
-        "images": [
-            {
-                "imageExe": "<STOREPATH>",
-                "imageName": "localhost/webserver",
-                "imageTag": "<HASH>"
-            }
-        ],
-        "project": {
-            "name": "unit-test-data"
-        },
-        "serviceInfo": {
-            "webserver": {
-                "defaultExec": [
-                    "/bin/sh"
-                ]
-            }
-        }
-    }
-}
--- a/src/haskell/testdata/Arion/NixSpec/arion-context-compose.nix
+++ b/src/haskell/testdata/Arion/NixSpec/arion-context-compose.nix
@ -1,9 +0,0 @@
-{
-  project.name = "unit-test-data";
-  services.webserver.service = {
-    build.context = "${./build-context}";
-    ports = [
-      "8080:80"
-    ];
-  };
-}
--- a/src/haskell/testdata/Arion/NixSpec/build-context/Dockerfile
+++ b/src/haskell/testdata/Arion/NixSpec/build-context/Dockerfile
@ -1,4 +0,0 @@
-FROM nginx
-
-RUN echo this is a dockerfile to be built
-
--- a/src/haskell/testdata/docker-compose-example.json
+++ b/src/haskell/testdata/docker-compose-example.json
@ -1,45 +0,0 @@
-{
-  "services": {
-    "webserver": {
-      "environment": {
-        "container": "docker"
-      },
-      "image": "webserver:xr4ljmz3qfcwlq9rl4mr4qdrzw93rl70",
-      "ports": [
-        "8000:80"
-      ],
-      "stop_signal": "SIGRTMIN+3",
-      "sysctls": {},
-      "tmpfs": [
-        "/run",
-        "/run/wrappers",
-        "/tmp:exec,mode=777"
-      ],
-      "tty": true,
-      "volumes": [
-        "/sys/fs/cgroup:/sys/fs/cgroup:ro"
-      ]
-    }
-  },
-  "version": "3.4",
-  "x-arion": {
-    "images": [
-      {
-        "image": "/nix/store/xr4ljmz3qfcwlq9rl4mr4qdrzw93rl70-docker-image-webserver.tar.gz",
-        "imageName": "webserver",
-        "imageTag": "xr4ljmz3qfcwlq9rl4mr4qdrzw93rl70"
-      }
-    ],
-    "project": {
-      "name": null
-    },
-    "serviceInfo": {
-      "webserver": {
-        "defaultExec": [
-          "/run/current-system/sw/bin/bash",
-          "-l"
-        ]
-      }
-    }
-  }
-}
--- a/src/nix/eval-composition.nix
+++ b/src/nix/eval-composition.nix
@ -12,26 +12,26 @@ let
  inherit (pkgs) lib;

  composition = lib.evalModules {
+    check = true;
    modules = builtinModules ++ modules;
  };

  builtinModules = [
    argsModule
-  ] ++ import ./modules.nix;
+    ./modules/composition/docker-compose.nix
+    ./modules/composition/host-environment.nix
+    ./modules/composition/images.nix
+    ./modules/composition/service-info.nix
+  ];

  argsModule = {
    _file = ./eval-composition.nix;
    key = ./eval-composition.nix;
    config._module.args.pkgs = lib.mkIf (pkgs != null) (lib.mkForce pkgs);
-    config._module.args.check = true;
    config.host.nixStorePrefix = hostNixStorePrefix;
    config.host.uid = lib.toInt uid;
  };

 in
-  # Typically you need composition.config.out.dockerComposeYaml
-  composition // {
-    # throw in lib and pkgs for repl convenience
-    inherit lib;
-    inherit (composition._module.args) pkgs;
-  }
+  # Typically you need composition.config.build.dockerComposeYaml
+  composition
--- a/src/nix/eval-service.nix
+++ b/src/nix/eval-service.nix
@ -0,0 +1,31 @@
+{ lib, pkgs, ... }:
+
+{ modules, host, name }:
+let
+  composite = lib.evalModules {
+    check = true;
+    modules = builtinModules ++ modules;
+  };
+
+  builtinModules = [
+    argsModule
+    ./modules/service/default-exec.nix
+    ./modules/service/docker-compose-service.nix
+    ./modules/service/extended-info.nix
+    ./modules/service/host-store.nix
+    ./modules/service/host.nix
+    ./modules/service/image.nix
+    ./modules/service/nixos.nix
+    ./modules/service/nixos-init.nix
+  ];
+
+  argsModule = {
+    _file = ./eval-service.nix;
+    key = ./eval-service.nix;
+    config._module.args.pkgs = lib.mkForce pkgs;
+    config.host = host;
+    config.service.name = name;
+  };
+
+in
+  composite
--- a/src/nix/lib.nix
+++ b/src/nix/lib.nix
@ -1,21 +0,0 @@
-{ lib }:
-let
-
-  link = url: text: ''[${text}](${url})'';
-
-  composeSpecRev = "55b450aee50799a2f33cc99e1d714518babe305e";
-
-  serviceRef = fragment:
-    ''See ${link "https://github.com/compose-spec/compose-spec/blob/${composeSpecRev}/05-services.md#${fragment}" "Compose Spec Services #${fragment}"}'';
-
-  networkRef = fragment:
-    ''See ${link "https://github.com/compose-spec/compose-spec/blob/${composeSpecRev}/06-networks.md#${fragment}" "Compose Spec Networks #${fragment}"}'';
-
-in
-{
-  inherit
-    link
-    networkRef
-    serviceRef
-    ;
-}
--- a/src/nix/modules.nix
+++ b/src/nix/modules.nix
@ -1,8 +0,0 @@
-[
-    ./modules/composition/docker-compose.nix
-    ./modules/composition/host-environment.nix
-    ./modules/composition/images.nix
-    ./modules/composition/networks.nix
-    ./modules/composition/service-info.nix
-    ./modules/composition/composition.nix
-]
--- a/src/nix/modules/composition/composition.nix
+++ b/src/nix/modules/composition/composition.nix
@ -1,28 +0,0 @@
-{ config, lib, ... }:
-let
-  inherit (lib) types mkOption;
-
-  link = url: text:
-    ''[${text}](${url})'';
-
-in
-{
-  options = {
-    _module.args = mkOption {
-      internal = true;
-    };
-    project.name = mkOption {
-      description = ''
-        Name of the project.
-
-        See ${link "https://docs.docker.com/compose/reference/envvars/#compose_project_name" "COMPOSE_PROJECT_NAME"}
-
-        This is not optional, because getting the project name from a directory name tends to produce different results for different repo checkout location names.
-      '';
-      type = types.str;
-    };
-  };
-  config = {
-    docker-compose.extended.project.name = config.project.name;
-  };
-}
--- a/src/nix/modules/composition/docker-compose.nix
+++ b/src/nix/modules/composition/docker-compose.nix
@ -3,53 +3,26 @@
   This is a composition-level module.

   It defines the low-level options that are read by arion, like
-    - out.dockerComposeYaml
+    - build.dockerComposeYaml

   It declares options like
-    - services
+    - docker-compose.services

 */
-compositionArgs@{ lib, config, options, pkgs, ... }:
+{ pkgs, lib, config, ... }:
 let
-  inherit (lib) types;
-
-  service = {
-    imports = [ argsModule ] ++ import ../service/all-modules.nix;
-  };
-  argsModule =
-    { name, # injected by types.submodule
-      ...
-    }: {
-      _file = ./docker-compose.nix;
-      key = ./docker-compose.nix;
-
-      config._module.args.pkgs = lib.mkDefault compositionArgs.pkgs;
-      config.host = compositionArgs.config.host;
-      config.composition = compositionArgs.config;
-      config.service.name = name;
-    };
+  evalService = name: modules: pkgs.callPackage ../../eval-service.nix {} { inherit name modules; inherit (config) host; };

 in
 {
-  imports = [
-    ../lib/assert.nix
-    (lib.mkRenamedOptionModule ["docker-compose" "services"] ["services"])
-  ];
  options = {
-    out.dockerComposeYaml = lib.mkOption {
+    build.dockerComposeYaml = lib.mkOption {
      type = lib.types.package;
      description = "A derivation that produces a docker-compose.yaml file for this composition.";
-      readOnly = true;
    };
-    out.dockerComposeYamlText = lib.mkOption {
-      type = lib.types.str;
-      description = "The text of out.dockerComposeYaml.";
-      readOnly = true;
-    };
-    out.dockerComposeYamlAttrs = lib.mkOption {
-      type = lib.types.attrsOf lib.types.unspecified;
-      description = "The text of out.dockerComposeYaml.";
-      readOnly = true;
+    build.dockerComposeYamlText = lib.mkOption {
+      type = lib.types.string;
+      description = "The text of build.dockerComposeYaml.";
    };
    docker-compose.raw = lib.mkOption {
      type = lib.types.attrs;
@ -59,26 +32,26 @@ in
      type = lib.types.attrs;
      description = "Attribute set that will be turned into the x-arion section of the docker-compose.yaml file.";
    };
-    services = lib.mkOption {
-      type = lib.types.attrsOf (lib.types.submodule service);
-      description = "An attribute set of service configurations. A service specifies how to run an image as a container.";
-    };
-    docker-compose.volumes = lib.mkOption {
-      type = lib.types.attrsOf lib.types.unspecified;
-      description = "A attribute set of volume configurations.";
+    docker-compose.services = lib.mkOption {
      default = {};
+      type = with lib.types; attrsOf (coercedTo unspecified (a: [a]) (listOf unspecified));
+      description = "A attribute set of service configurations. A service specifies how to run an image. Each of these service configurations is specified using modules whose options are described in the Service Options section.";
+    };
+    docker-compose.evaluatedServices = lib.mkOption {
+      type = lib.types.attrsOf lib.types.attrs;
+      description = "Attribute set of evaluated service configurations.";
+      readOnly = true;
    };
  };
  config = {
-    out.dockerComposeYaml = pkgs.writeText "docker-compose.yaml" config.out.dockerComposeYamlText;
-    out.dockerComposeYamlText = builtins.toJSON (config.out.dockerComposeYamlAttrs);
-    out.dockerComposeYamlAttrs = config.assertWarn config.docker-compose.raw;
+    build.dockerComposeYaml = pkgs.writeText "docker-compose.yaml" config.build.dockerComposeYamlText;
+    build.dockerComposeYamlText = builtins.toJSON (config.docker-compose.raw);

+    docker-compose.evaluatedServices = lib.mapAttrs evalService config.docker-compose.services;
    docker-compose.raw = {
      version = "3.4";
-      services = lib.mapAttrs (k: c: c.out.service) config.services;
+      services = lib.mapAttrs (k: c: c.config.build.service) config.docker-compose.evaluatedServices;
      x-arion = config.docker-compose.extended;
-      volumes = config.docker-compose.volumes;
    };
  };
 }
--- a/src/nix/modules/composition/host-environment.nix
+++ b/src/nix/modules/composition/host-environment.nix
@ -15,7 +15,7 @@
    };

    host.nixStorePrefix = lib.mkOption {
-      type = lib.types.str;
+      type = lib.types.string;
      default = "";
      example = "/mnt/foo";
      description = ''
@ -23,9 +23,9 @@
        stored at an alternate location without altering the format of
        store paths.

-        For example: instead of mounting the host's `/nix/store` as the
-        container's `/nix/store`, this will mount `/mnt/foo/nix/store`
-        as the container's `/nix/store`.
+        For example: instead of mounting the host's /nix/store as the
+        container's /nix/store, this will mount /mnt/foo/nix/store
+        as the container's /nix/store.
      '';
    };

--- a/src/nix/modules/composition/images.nix
+++ b/src/nix/modules/composition/images.nix
@ -4,39 +4,31 @@ let

  serviceImages =
    lib.mapAttrs addDetails (
-      lib.filterAttrs filterFunction config.services
+      lib.filterAttrs filterFunction config.docker-compose.evaluatedServices
    );

  filterFunction = serviceName: service:
    builtins.addErrorContext "while evaluating whether the service ${serviceName} defines an image"
-      service.image.nixBuild;
+      service.config.image.nixBuild;

  addDetails = serviceName: service:
    builtins.addErrorContext "while evaluating the image for service ${serviceName}"
    (let
-      inherit (service) build;
+      inherit (service.config) build;
    in {
+      image = build.image.outPath;
      imageName = build.imageName or service.image.name;
      imageTag =
                 if build.image.imageTag != ""
                 then build.image.imageTag
                 else lib.head (lib.strings.splitString "-" (baseNameOf build.image.outPath));
-    } // (if build.image.isExe or false
-        then {
-          imageExe = build.image.outPath;
-        }
-        else {
-          image = build.image.outPath;
-        }
-      )
-    );
+    });
 in
 {
  options = {
    build.imagesToLoad = lib.mkOption {
      type = listOf unspecified;
-      internal = true;
-      description = "List of `dockerTools` image derivations.";
+      description = "List of dockerTools image derivations.";
    };
  };
  config = {
--- a/src/nix/modules/composition/networks.nix
+++ b/src/nix/modules/composition/networks.nix
@ -1,53 +0,0 @@
-{ config, lib, ... }:
-
-let
-  inherit (lib)
-    mkOption
-    optionalAttrs
-    types
-    ;
-  inherit (import ../../lib.nix { inherit lib; })
-    link
-    ;
-in
-{
-  options = {
-    networks = mkOption {
-      type = types.lazyAttrsOf (types.submoduleWith {
-        modules = [
-          ../networks/network.nix
-        ];
-      });
-      description = ''
-        See ${link "https://docs.docker.com/compose/compose-file/06-networks/" "Docker Compose Networks"}
-      '';
-    };
-    enableDefaultNetwork = mkOption {
-      type = types.bool;
-      description = ''
-        Whether to define the default network:
-
-        ```nix
-        networks.default = {
-          name = config.project.name;
-        };
-        ```
-      '';
-      default = true;
-    };
-  };
-
-
-  config = {
-
-    networks = optionalAttrs config.enableDefaultNetwork {
-      default = {
-        name = config.project.name;
-      };
-    };
-
-    docker-compose.raw.networks =
-      lib.mapAttrs (k: v: v.out) config.networks;
-
-  };
-}
--- a/src/nix/modules/composition/service-info.nix
+++ b/src/nix/modules/composition/service-info.nix
@ -5,14 +5,17 @@
 */
 { config, lib, ... }:
 let
-  inherit (lib) mapAttrs filterAttrs;
-
  serviceInfo =
-    filterAttrs (_k: v: v != {})
-      (mapAttrs (_serviceName: service: service.out.extendedInfo)
-        config.services
+    lib.mapAttrs getInfo (
+      lib.filterAttrs filterFunction config.docker-compose.evaluatedServices
    );

+  filterFunction = _serviceName: service:
+    # shallow equality suffices for emptiness test
+    builtins.attrNames service.config.build.extendedInfo != [];
+
+  getInfo = _serviceName: service: service.config.build.extendedInfo;
+
 in
 {
  config = {
--- a/src/nix/modules/lib/README.md
+++ b/src/nix/modules/lib/README.md
@ -1,2 +0,0 @@
-`assertions.nix`: Nixpkgs
-`assert.nix`: extracted from Nixpkgs, adapted
--- a/src/nix/modules/lib/assert.nix
+++ b/src/nix/modules/lib/assert.nix
@ -1,33 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-# based on nixpkgs/nixos/modules/system/activation/top-level.nix
-
-let
-  inherit (lib)
-    concatStringsSep
-    filter
-    mkOption
-    showWarnings
-    types
-    ;
-
-  # Handle assertions and warnings
-  failedAssertions = map (x: x.message) (filter (x: !x.assertion) config.assertions);
-
-  assertWarn = if failedAssertions != []
-    then throw "\nFailed assertions:\n${concatStringsSep "\n" (map (x: "- ${x}") failedAssertions)}"
-    else showWarnings config.warnings;
-
-in
-
-{
-  imports = [ ./assertions.nix ];
-  options.assertWarn = mkOption {
-    type = types.unspecified; # a function
-    # It's for the wrapping program to know about this. User need not care.
-    internal = true;
-    readOnly = true;
-  };
-  config = { inherit assertWarn; };
-}
-
--- a/src/nix/modules/lib/assertions.nix
+++ b/src/nix/modules/lib/assertions.nix
@ -1,34 +0,0 @@
-{ lib, ... }:
-
-with lib;
-
-{
-
-  options = {
-
-    assertions = mkOption {
-      type = types.listOf types.unspecified;
-      internal = true;
-      default = [];
-      example = [ { assertion = false; message = "you can't enable this for that reason"; } ];
-      description = ''
-        This option allows modules to express conditions that must
-        hold for the evaluation of the system configuration to
-        succeed, along with associated error messages for the user.
-      '';
-    };
-
-    warnings = mkOption {
-      internal = true;
-      default = [];
-      type = types.listOf types.str;
-      example = [ "The `foo' service is deprecated and will go away soon!" ];
-      description = ''
-        This option allows modules to show warnings to users during
-        the evaluation of the system configuration.
-      '';
-    };
-
-  };
-  # impl of assertions is in <nixpkgs/nixos/modules/system/activation/top-level.nix>
-}
--- a/Show more
+++ b/Show more
				`@ -1 +0,0 @@`
				`../../../../../examples/full-nixos/arion-compose.nix`
				`@ -1 +0,0 @@`
				`../../../../../examples/minimal/arion-compose.nix`
				`@ -1 +0,0 @@`
				`../../../../../examples/nixos-unit/arion-compose.nix`
				`@ -1 +0,0 @@`
				`(builtins.getFlake ("git+file://" + toString ./.)).devShells.${builtins.currentSystem}.default`