Merge pull request #108 from hercules-ci/labels

Add service.labels

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Revision history for Arion
 
+## Next
+
+* Support `service.labels`, which is useful for autodiscovery among other things.
+
+* Add a tested example for Traefik with label-based routing.
+
+* Drop obsolete NixOS 19.09 and 20.03 support. It may still be usable there.
+
 ## 0.1.2.0 -- 2020-03-05
 
 * Support use of prebuilt `docker-compose.yaml`.

docs/modules/ROOT/partials/NixOSOptions.adoc

@@ -676,6 +676,28 @@ No Default:: {blank}
 
 No Example:: {blank}
 
+== services.<name>.service.labels
+
+See link:https://docs.docker.com/compose/compose-file/#labels[Docker Compose#labels]
+
+[discrete]
+=== details
+
+Type:: attribute set of strings
+Default::
++
+----
+{}
+----
+
+
+Example::
++
+----
+{"com.example.foo":"bar","traefik.enable":"true","traefik.http.routers.my-service.entrypoints":"web","traefik.http.routers.my-service.rule":"Host(`my-service.localhost`)"}
+----
+
+
 == services.<name>.service.links
 
 See link:https://docs.docker.com/compose/compose-file/#links[Docker Compose#links]

examples/traefik/arion-compose.nix

@@ -0,0 +1,49 @@
+/*
+ 
+  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.services = {
+    traefik = {
+      image.command = [
+        "${pkgs.traefik}/bin/traefik"
+        "--api.insecure=true"
+        "--providers.docker=true"
+        "--providers.docker.exposedbydefault=false"
+        "--entrypoints.web.address=:80"
+      ];
+      service = {
+        container_name = "traefik";
+        stop_signal = "SIGINT";
+        ports = [ "80:80" "8080:8080" ];
+        volumes = [ "/var/run/docker.sock:/var/run/docker.sock:ro" ];
+      };
+    };
+
+    nix-docs = {
+      image.command = ["${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.ports = [
+        "8000:8000" # host:container
+      ];
+      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";
+      };
+    };
+  };
+}
+

examples/traefik/arion-pkgs.nix

@@ -0,0 +1,6 @@
+# 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";
+}

nix/ci.nix

@@ -1,6 +1,6 @@
 let
   sources = import ./sources.nix;
-  lib = import (sources."nixos-20.03" + "/lib");
+  lib = import (sources."nixos-unstable" + "/lib");
   inherit (import (sources."project.nix" + "/lib/dimension.nix") { inherit lib; }) dimension;
 in
 
@@ -14,16 +14,6 @@ dimension "Nixpkgs version" {
       enableDoc = false;
       nixosTestIsPerl = true;
     };
-    "nixos-19_09" = {
-      nixpkgsSource = "nixos-19.09";
-      enableDoc = false;
-      nixosTestIsPerl = true;
-    };
-    "nixos-20_03" = {
-      nixpkgsSource = "nixos-20.03";
-      isReferenceNixpkgs = false;
-      enableDoc = true;
-    };
     "nixos-20_09" = {
       nixpkgsSource = "nixos-20.09";
       isReferenceNixpkgs = true;

nix/sources.json

@@ -23,30 +23,6 @@
         "url": "https://github.com/NixOS/nixpkgs-channels/archive/34c7eb7545d155cc5b6f499b23a7cb1c96ab4d59.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
-    "nixos-19.09": {
-        "branch": "nixos-19.09",
-        "description": "A read-only mirror of NixOS/nixpkgs tracking the released channels. Send issues and PRs to",
-        "homepage": "https://github.com/NixOS/nixpkgs",
-        "owner": "NixOS",
-        "repo": "nixpkgs-channels",
-        "rev": "289466dd6a11c65a7de4a954d6ebf66c1ad07652",
-        "sha256": "0r5ja052s86fr54fm1zlhld3fwawz2w1d1gd6vbvpjrpjfyajibn",
-        "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs-channels/archive/289466dd6a11c65a7de4a954d6ebf66c1ad07652.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixos-20.03": {
-        "branch": "release-20.03",
-        "description": "A read-only mirror of NixOS/nixpkgs tracking the released channels. Send issues and PRs to",
-        "homepage": "https://github.com/NixOS/nixpkgs",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "b4db68ff563895eea6aab4ff24fa04ef403dfe14",
-        "sha256": "1qbs7p0mmcmpg70ibd437hl57byqx5q0pc61p1dckrkazj7kq0pc",
-        "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/b4db68ff563895eea6aab4ff24fa04ef403dfe14.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
     "nixos-20.09": {
         "branch": "nixos-20.09",
         "description": "Nix Packages collection",

src/nix/modules/service/docker-compose-service.nix

@@ -115,6 +115,17 @@ in
         ${dockerComposeRef "devices"}
       '';
     };
+    service.labels = mkOption {
+      type = attrsOf str;
+      default = {};
+      example = {
+        "com.example.foo" = "bar";
+        "traefik.enable" = "true";
+        "traefik.http.routers.my-service.rule" = "Host(`my-service.localhost`)";
+        "traefik.http.routers.my-service.entrypoints" = "web";
+      };
+      description = dockerComposeRef "labels";
+    };
     service.links = mkOption {
       type = listOf str;
       default = [];
@@ -247,6 +258,8 @@ in
     inherit (config.service) extra_hosts;
   } // lib.optionalAttrs (config.service.hostname != null) {
     inherit (config.service) hostname;
+  } // lib.optionalAttrs (config.service.labels != {}) {
+    inherit (config.service) labels;
   } // lib.optionalAttrs (config.service.links != []) {
     inherit (config.service) links;
   } // lib.optionalAttrs (config.service.ports != []) {

tests/arion-test/default.nix

@@ -33,13 +33,14 @@ in
       (preEval [ ../../examples/minimal/arion-compose.nix ]).config.out.dockerComposeYaml
       (preEval [ ../../examples/full-nixos/arion-compose.nix ]).config.out.dockerComposeYaml
       (preEval [ ../../examples/nixos-unit/arion-compose.nix ]).config.out.dockerComposeYaml
+      (preEval [ ../../examples/traefik/arion-compose.nix ]).config.out.dockerComposeYaml
       pkgs.stdenv
     ];
 
     virtualisation.memorySize = 1024;
   };
   testScript = ''
-    machine.fail("curl localhost:8000")
+    machine.fail("curl --fail localhost:8000")
     machine.succeed("docker --version")
 
     # Tests
@@ -50,11 +51,11 @@ in
         machine.succeed(
             "rm -rf work && cp -frT ${../../examples/minimal} work && cd work && NIX_PATH=nixpkgs='${pkgs.path}' arion up -d"
         )
-        machine.wait_until_succeeds("curl localhost:8000")
+        machine.wait_until_succeeds("curl --fail localhost:8000")
         machine.succeed(
             "cd work && NIX_PATH=nixpkgs='${pkgs.path}' arion down"
         )
-        machine.wait_until_fails("curl localhost:8000")
+        machine.wait_until_fails("curl --fail localhost:8000")
 
     # Tests
     #  - arion exec
@@ -63,7 +64,7 @@ in
         machine.succeed(
             "rm -rf work && cp -frT ${../../examples/full-nixos} work && cd work && NIX_PATH=nixpkgs='${pkgs.path}' arion up -d"
         )
-        machine.wait_until_succeeds("curl localhost:8000")
+        machine.wait_until_succeeds("curl --fail localhost:8000")
 
         machine.succeed(
             """
@@ -79,7 +80,7 @@ in
         machine.succeed(
             "cd work && NIX_PATH=nixpkgs='${pkgs.path}' arion down"
         )
-        machine.wait_until_fails("curl localhost:8000")
+        machine.wait_until_fails("curl --fail localhost:8000")
 
     # Tests
     #  - examples/nixos-unit
@@ -87,10 +88,23 @@ in
         machine.succeed(
             "rm -rf work && cp -frT ${../../examples/nixos-unit} work && cd work && NIX_PATH=nixpkgs='${pkgs.path}' arion up -d"
         )
-        machine.wait_until_succeeds("curl localhost:8000")
+        machine.wait_until_succeeds("curl --fail localhost:8000")
         machine.succeed(
             "cd work && NIX_PATH=nixpkgs='${pkgs.path}' arion down"
         )
-        machine.wait_until_fails("curl localhost:8000")
+        machine.wait_until_fails("curl --fail localhost:8000")
+
+    # Tests
+    # - examples/traefik
+    # - labels
+    with subtest("traefik"):
+        machine.succeed(
+            "rm -rf work && cp -frT ${../../examples/traefik} work && cd work && NIX_PATH=nixpkgs='${pkgs.path}' arion up -d"
+        )
+        machine.wait_until_succeeds("curl --fail nix-docs.localhost")
+        machine.succeed(
+            "cd work && NIX_PATH=nixpkgs='${pkgs.path}' arion down"
+        )
+        machine.wait_until_fails("curl --fail nix-docs.localhost")
   '';
 }