WIP NixOS-style docs

See https://github.com/hercules-ci/arion/issues/10

doc/default.nix

@@ -0,0 +1,8 @@
+{ pkgs ? import ../nix {} }:
+let
+  inherit (pkgs) recurseIntoAttrs callPackage;
+in
+
+recurseIntoAttrs {
+  manual = callPackage ./manual {};
+}

doc/manual/default.nix

@@ -0,0 +1,66 @@
+{ pkgs ? import ../../nix {} }:
+let
+  inherit (pkgs) recurseIntoAttrs callPackage runCommand lib;
+
+  nixosManualPath = s: "${pkgs.path}/nixos/doc/manual/${s}";
+  revision = "0.0-fixme"; # FIXME
+
+  # NixOS module system options in JSON format.
+  options = { moduleType, description, optionsList }: recurseIntoAttrs rec {
+    optionsXML = builtins.toFile "options.xml" (builtins.toXML optionsList);
+
+    optionsDocBook = runCommand "options-db.xml" {} ''
+      optionsXML=${optionsXML}
+      if grep /nixpkgs/nixos/modules $optionsXML; then
+        echo "The manual appears to depend on the location of Nixpkgs, which is bad"
+        echo "since this prevents sharing via the NixOS channel.  This is typically"
+        echo "caused by an option default that refers to a relative path (see above"
+        echo "for hints about the offending path)."
+        exit 1
+      fi
+      ${pkgs.buildPackages.libxslt.bin}/bin/xsltproc \
+        --stringparam revision '${revision}' \
+        -o intermediate.xml ${nixosManualPath "options-to-docbook.xsl"} $optionsXML
+      ${pkgs.buildPackages.libxslt.bin}/bin/xsltproc \
+        -o "$out" ${nixosManualPath "postprocess-option-descriptions.xsl"} intermediate.xml
+    '';
+    
+    optionsJSON = runCommand "${moduleType}-options-json" {
+      meta.description = description;
+    } ''
+      # Export list of options in different format.
+      dst=$out/share/doc/arion
+      mkdir -p $dst
+
+      cp ${builtins.toFile "options-${moduleType}.json" (builtins.unsafeDiscardStringContext (builtins.toJSON
+        (builtins.listToAttrs (map (o: { name = o.name; value = removeAttrs o ["name" "visible" "internal"]; }) optionsList))))
+      } $dst/options-${moduleType}.json
+
+      mkdir -p $out/nix-support
+      echo "file json $dst/options-${moduleType}.json" >> $out/nix-support/hydra-build-products
+    '';
+
+    
+  };
+
+in
+
+recurseIntoAttrs rec {
+  compositionOptions = options {
+    moduleType = "composition";
+    description = "List of Arion composition-level options in JSON format";
+    optionsList = let composition = import ../../src/nix/eval-composition.nix { inherit pkgs; };
+                  in lib.optionAttrSetToDocList composition.options;
+  };
+  serviceOptions = options {
+    moduleType = "service";
+    description = "List of Arion service-level options in JSON format";
+    optionsList = let composition = pkgs.callPackage ../../src/nix/eval-service.nix {} { modules = []; uid = -1; };
+                  in 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
+  '';
+}

nix/overlay.nix

@@ -1,4 +1,5 @@
 self: super: {
   arion = super.callPackage ../arion.nix {};
   tests = super.callPackage ../tests {};
+  doc = super.callPackage ../doc {};
 }

src/nix/docker-compose-module.nix

@@ -12,44 +12,27 @@
 { pkgs, uid, lib, config, ... }:
 
 let
-  evalService = name: modules:
+  evalService = name: modules: (pkgs.callPackage ./eval-service.nix {} { inherit modules uid; }).config.build.service;
-    let
-      composite = lib.evalModules {
-        check = true;
-        modules = builtinModules ++ modules;
-      };
-
-      builtinModules = [
-        argsModule
-        ./service.nix
-        ./service-host-store.nix
-      ];
-
-      argsModule = {
-        _file = ./docker-compose-module.nix;
-        key = ./docker-compose-module.nix;
-        config._module.args.pkgs = lib.mkForce pkgs;
-        config._module.args.uid = uid;
-      };
-
-    in
-      composite.config.build.service;
 
 in
 {
   options = {
     build.dockerComposeYaml = lib.mkOption {
       type = lib.types.package;
+      description = "";
     };
     build.dockerComposeYamlText = lib.mkOption {
       type = lib.types.string;
+      description = "";
     };
     docker-compose.raw = lib.mkOption {
       type = lib.types.attrs;
+      description = "";
     };
     docker-compose.services = lib.mkOption {
       default = {};
       type = with lib.types; attrsOf (coercedTo unspecified (a: [a]) (listOf unspecified));
+      description = "";
     };
   };
   config = {

src/nix/eval-service.nix

@@ -0,0 +1,24 @@
+{ lib, pkgs, ... }:
+
+{ modules, uid }:
+let
+  composite = lib.evalModules {
+    check = true;
+    modules = builtinModules ++ modules;
+  };
+
+  builtinModules = [
+    argsModule
+    ./service.nix
+    ./service-host-store.nix
+  ];
+
+  argsModule = {
+    _file = ./docker-compose-module.nix;
+    key = ./docker-compose-module.nix;
+    config._module.args.pkgs = lib.mkForce pkgs;
+    config._module.args.uid = uid;
+  };
+
+in
+  composite

src/nix/service.nix

@@ -15,37 +15,46 @@ in
     service.volumes = mkOption {
       type = listOf types.unspecified;
       default = [];
+      description = "";
     };
     service.build.context = mkOption {
       type = nullOr string;
       default = null;
+      description = "";
     };
     service.environment = mkOption {
       type = attrsOf (either string int);
       default = {};
+      description = "";
     };
     service.image = mkOption {
       type = string;
+      description = "";
     };
     service.command = mkOption {
       type = nullOr types.unspecified;
       default = null;
+      description = "";
     };
     service.depends_on = mkOption {
       type = listOf string;
       default = [];
+      description = "";
     };
     service.working_dir = mkOption {
       type = nullOr string;
       default = null;
+      description = "";
     };
     service.entrypoint = mkOption {
       type = nullOr string;
       default = null;
+      description = "";
     };
     service.restart = mkOption {
       type = nullOr string;
       default = null;
+      description = "";
     };
     service.ports = mkOption {
       type = listOf types.unspecified;
@@ -58,10 +67,12 @@ in
     service.expose = mkOption {
       type = listOf string;
       default = [];
+      description = "";
     };
 
     build.service = mkOption {
       type = attrsOf types.unspecified;
+      description = "";
     };
   };
 

tests/default.nix

@@ -5,4 +5,5 @@ in
 
 recurseIntoAttrs {
   test = nixosTest ./arion-test;
+  preEval = pkgs.callPackage ./arion-test/preeval.nix {};
 }