packer: add withPlugins

doc/packages/index.md

@@ -25,6 +25,7 @@ etc-files.section.md
 nginx.section.md
 nrfutil.section.md
 opengl.section.md
+packer.section.md
 shell-helpers.section.md
 python-tree-sitter.section.md
 treefmt.section.md

doc/packages/packer.section.md

@@ -0,0 +1,70 @@
+# Packer {#sec-packer}
+
+[Packer](https://www.packer.io) is a tool for creating identical machine images
+for multiple platforms from a single source configuration.
+
+## Using Packer with plugins {#sec-packer-with-plugins}
+
+Packer's functionality is extended through
+[plugins](https://developer.hashicorp.com/packer/docs/plugins). Rather than
+letting Packer download plugins at runtime, you can build a Packer wrapper that
+bundles the plugins you need with `packer.withPlugins`.
+
+`packer.withPlugins` takes a function that receives the set of available plugins
+and returns the list of plugins to include:
+
+```nix
+packer.withPlugins (ps: [ ps.docker ])
+```
+
+This produces a `packer` executable wrapped with the `PACKER_PLUGIN_PATH`
+environment variable set, so the selected plugins are available without a
+separate `packer plugins install` step.
+
+For example, to get a development shell with Packer and the Docker plugin:
+
+```nix
+{
+  pkgs ? import <nixpkgs> { },
+}:
+
+pkgs.mkShell {
+  packages = [
+    (pkgs.packer.withPlugins (ps: [ ps.docker ]))
+  ];
+}
+```
+
+Multiple plugins can be selected at once:
+
+```nix
+packer.withPlugins (ps: [
+  ps.docker
+  ps.qemu
+])
+```
+
+## Listing available plugins {#sec-packer-list-plugins}
+
+The packaged plugins are exposed as the `packer.plugins` attribute set. To list
+every plugin available in your version of Nixpkgs, query its attribute names:
+
+```ShellSession
+$ nix eval nixpkgs#packer.plugins --apply builtins.attrNames
+[ "docker" "qemu" ]
+```
+
+Without flakes:
+
+```ShellSession
+$ nix-env -f '<nixpkgs>' -qaP -A packer.plugins
+packer.plugins.docker  packer-plugin-docker-1.1.2
+packer.plugins.qemu    packer-plugin-qemu-1.1.4
+```
+
+The attribute name (for example `docker` or `qemu`) is what you pass to
+`packer.withPlugins`.
+
+Notes:
+
+- `mkPackerPlugin` currently only supports `fetchFromGitHub` as the fetcher.

doc/redirects.json

@@ -620,6 +620,15 @@
   "chap-overrides": [
     "index.html#chap-overrides"
   ],
+  "sec-packer": [
+    "index.html#sec-packer"
+  ],
+  "sec-packer-list-plugins": [
+    "index.html#sec-packer-list-plugins"
+  ],
+  "sec-packer-with-plugins": [
+    "index.html#sec-packer-with-plugins"
+  ],
   "sec-pkg-override": [
     "index.html#sec-pkg-override"
   ],

pkgs/by-name/pa/packer/extra/mk-packer-plugin.nix

@@ -0,0 +1,100 @@
+let
+  platformSuffix = {
+    x86_64-linux = "linux_amd64";
+    x86_64-darwin = "darwin_amd64";
+    aarch64-linux = "linux_arm64";
+    aarch64-darwin = "darwin_arm64";
+  };
+in
+
+{
+  stdenv,
+  lib,
+  buildGoModule,
+  versionCheckHook,
+  nix-update-script,
+}:
+
+lib.extendMkDerivation {
+  constructDrv = buildGoModule;
+
+  excludeDrvArgNames = [
+    "apiVersion"
+  ];
+
+  extendDrvArgs =
+    finalAttrs:
+    {
+      pname,
+      version,
+      src,
+      ldflags ? [ ],
+      nativeInstallCheckInputs ? [ ],
+      postFixup ? "",
+      subPackages ? [ "." ],
+      apiVersion ? "x5.0",
+      versionCheckProgramArg ? "describe",
+      doInstallCheck ? true,
+      ...
+    }@prevAttrs:
+    # Packer expects plugins to be hosted on GitHub and follow a specific release structure
+    # (see: https://developer.hashicorp.com/packer/docs/plugins/creation#creating-a-github-release).
+    # This introduces two requirements:
+    #
+    # 1. Directory Structure: Packer expects the plugin binary to reside in:
+    #    $PACKER_PLUGIN_PATH/github.com/$OWNER/$TYPE/
+    #    where $TYPE is the repo name without the "packer-plugin-" prefix.
+    #
+    # 2. Configuration Source: When declaring the plugin in a Packer template, the `source`
+    #    attribute must match this GitHub address format (e.g.: "github.com/$OWNER/$TYPE")
+    let
+      _ = lib.assertMsg (
+        src ? repo && src ? owner && src ? githubBase
+      ) "mk-packer-plugin: fetchFromGitHub is currently the only supported fetcher";
+      suffix =
+        platformSuffix."${stdenv.hostPlatform.system}"
+          or (throw "Unsupported system: ${stdenv.hostPlatform.system}");
+      binName = "${finalAttrs.src.repo}_v${finalAttrs.version}_${apiVersion}_${suffix}";
+    in
+    {
+      inherit
+        subPackages
+        doInstallCheck
+        versionCheckProgramArg
+        ;
+
+      __structuredAttrs = true;
+      strictDeps = true;
+
+      ldflags =
+        ldflags
+        ++ (
+          let
+            versionFlag = "${finalAttrs.src.githubBase}/${finalAttrs.src.owner}/${finalAttrs.src.repo}/version";
+          in
+          [
+            "-s"
+            "-w"
+            "-X ${versionFlag}.Version=${finalAttrs.version}"
+            "-X ${versionFlag}.VersionPrerelease="
+          ]
+        );
+
+      versionCheckProgram = prevAttrs.versionCheckProgram or "${placeholder "out"}/bin/${binName}";
+
+      nativeInstallCheckInputs = nativeInstallCheckInputs ++ [ versionCheckHook ];
+
+      # Generate checksums AFTER fixup phase when binary is finalized
+      postFixup = postFixup + ''
+        mv "$out/bin/${finalAttrs.src.repo}" "$out/bin/${binName}"
+        sha256sum "$out/bin/${binName}" | cut -d' ' -f1 > "$out/bin/${binName}_SHA256SUM"
+      '';
+
+      meta.mainProgram = binName;
+
+      passthru = {
+        pluginPath = "${finalAttrs.src.githubBase}/${finalAttrs.src.owner}/${lib.removePrefix "packer-plugin-" finalAttrs.src.repo}/${binName}";
+        updateScript = prevAttrs.passthru.updateScript or (nix-update-script { });
+      };
+    };
+}

pkgs/by-name/pa/packer/package.nix

@@ -3,16 +3,18 @@
   buildGoModule,
   fetchFromGitHub,
   installShellFiles,
+  callPackage,
+  runCommand,
 }:
 
-buildGoModule rec {
+buildGoModule (finalAttrs: {
   pname = "packer";
   version = "1.15.4";
 
   src = fetchFromGitHub {
     owner = "hashicorp";
     repo = "packer";
-    rev = "v${version}";
+    tag = "v${finalAttrs.version}";
     hash = "sha256-mhHES+/FCvVBBQm1qDQeH6WY2c9hIV7N3iFBCqJqJLw=";
   };
 
@@ -31,6 +33,46 @@ buildGoModule rec {
     installShellCompletion --zsh contrib/zsh-completion/_packer
   '';
 
+  passthru =
+    let
+      pluginScope = callPackage ./plugins.nix { };
+    in
+    {
+      plugins = lib.filterAttrs (_: lib.isDerivation) pluginScope;
+
+      withPlugins =
+        f:
+        (callPackage ./with-plugins.nix {
+          packer = finalAttrs.finalPackage;
+          packerPlugins = pluginScope;
+        })
+          { selector = f; };
+
+      tests.withPlugins =
+        let
+          packer-with-docker = finalAttrs.passthru.withPlugins (ps: [ ps.docker ]);
+        in
+        runCommand "packer-test-with-plugins"
+          {
+            nativeBuildInputs = [ packer-with-docker ];
+          }
+          ''
+            packer plugins installed > output.txt
+            cat output.txt
+
+            expected_path="${finalAttrs.passthru.plugins.docker.pluginPath}"
+            if ! grep -q "$expected_path" output.txt; then
+              echo "ERROR: Expected plugin path not found in 'packer plugins installed' output"
+              echo "Expected: $expected_path"
+              echo "Got:"
+              cat output.txt
+              exit 1
+            fi
+
+            touch $out
+          '';
+    };
+
   meta = {
     description = "Tool for creating identical machine images for multiple platforms from a single source configuration";
     homepage = "https://www.packer.io";
@@ -40,7 +82,8 @@ buildGoModule rec {
       ma27
       techknowlogick
       qjoly
+      jlesquembre
     ];
-    changelog = "https://github.com/hashicorp/packer/blob/v${version}/CHANGELOG.md";
+    changelog = "https://github.com/hashicorp/packer/blob/v${finalAttrs.version}/CHANGELOG.md";
   };
-}
+})

pkgs/by-name/pa/packer/plugins.nix

@@ -0,0 +1,19 @@
+{
+  lib,
+  newScope,
+}:
+lib.makeScope newScope (
+  self:
+  let
+    packages = lib.packagesFromDirectoryRecursive {
+      inherit (self) callPackage;
+      directory = ./plugins;
+    };
+  in
+  {
+    mkPackerPlugin = self.callPackage ./extra/mk-packer-plugin.nix { };
+  }
+  // lib.mapAttrs' (
+    name: pkg: lib.nameValuePair (lib.removePrefix "packer-plugin-" name) pkg
+  ) packages
+)

pkgs/by-name/pa/packer/plugins/packer-plugin-docker/package.nix

@@ -0,0 +1,27 @@
+{
+  lib,
+  mkPackerPlugin,
+  fetchFromGitHub,
+}:
+
+mkPackerPlugin (finalAttrs: {
+
+  pname = "packer-plugin-docker";
+  version = "1.1.2";
+
+  src = fetchFromGitHub {
+    owner = "hashicorp";
+    repo = "packer-plugin-docker";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-h89FGwUQjTk81CYUe1xmKxSHr1t3wyBg9lHUTqmVym8=";
+  };
+
+  vendorHash = "sha256-mvyafYSLi/q7lWorfKc4Gc4oM7yti3v/bLcVnNkH7ZY=";
+
+  meta = {
+    description = "Packer plugin for Docker";
+    homepage = "https://github.com/hashicorp/packer-plugin-docker";
+    license = lib.licenses.mpl20;
+    maintainers = with lib.maintainers; [ jlesquembre ];
+  };
+})

pkgs/by-name/pa/packer/plugins/packer-plugin-qemu/package.nix

@@ -0,0 +1,27 @@
+{
+  lib,
+  mkPackerPlugin,
+  fetchFromGitHub,
+}:
+
+mkPackerPlugin (finalAttrs: {
+
+  pname = "packer-plugin-qemu";
+  version = "1.1.4";
+
+  src = fetchFromGitHub {
+    owner = "hashicorp";
+    repo = "packer-plugin-qemu";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-Ose7ueo9V2zJ5K5yvew9ErTD9lR+rkp1UB/yDi+U+fY=";
+  };
+
+  vendorHash = "sha256-pgfI/ntG6Fesimw3jk70GP+lBUEUMfq6wbqXx8xCTf0=";
+
+  meta = {
+    description = "Packer plugin for QEMU";
+    homepage = "https://github.com/hashicorp/packer-plugin-qemu";
+    license = lib.licenses.mpl20;
+    maintainers = with lib.maintainers; [ jlesquembre ];
+  };
+})

pkgs/by-name/pa/packer/with-plugins.nix

@@ -0,0 +1,54 @@
+{
+  lib,
+  packer,
+  packerPlugins,
+  makeBinaryWrapper,
+  linkFarm,
+  stdenvNoCC,
+}:
+lib.extendMkDerivation {
+  constructDrv = stdenvNoCC.mkDerivation;
+
+  excludeDrvArgNames = [
+    "derivationArgs"
+    "selector"
+  ];
+
+  extendDrvArgs =
+    finalAttrs:
+    {
+      selector ? (_: [ ]),
+      name ? "packer-with-plugins",
+      nativeBuildInputs ? [ makeBinaryWrapper ],
+      ...
+    }:
+    let
+      plugins = selector packerPlugins;
+      pluginFarm = linkFarm "packer-plugins" (
+        builtins.concatMap (p: [
+          {
+            name = p.pluginPath;
+            path = "${p}/bin/${p.meta.mainProgram}";
+          }
+          {
+            name = "${p.pluginPath}_SHA256SUM";
+            path = "${p}/bin/${p.meta.mainProgram}_SHA256SUM";
+          }
+        ]) plugins
+      );
+    in
+    {
+      inherit name nativeBuildInputs;
+      __structuredAttrs = true;
+      strictDeps = true;
+
+      meta.mainProgram = "packer";
+
+      dontUnpack = true;
+
+      buildCommand = ''
+        makeWrapper "${packer}/bin/packer" "$out/bin/packer" \
+          --set PACKER_PLUGIN_PATH "${pluginFarm}"
+      '';
+    };
+}