Fix self-hosting

app/src/dist/share/gradle-env.nix

@@ -1,54 +1,130 @@
 # This file is generated by gradle2nix.
+#
+# Example usage (e.g. in default.nix):
+#
+#     with (import <nixpkgs> {});
+#     let
+#       buildGradle = callPackage ./gradleEnv.nix {};
+#     in
+#       buildGradle {
+#         envSpec = ./gradle-env.json;
+#
+#         src = ./.;
+#
+#         gradleFlags = [ "installDist" ];
+#
+#         installPhase = ''
+#           mkdir -p $out
+#           cp -r app/build/install/myproject $out
+#         '';
+#       }
 
-{ stdenvNoCC, lib, buildEnv, fetchurl }:
+{ stdenv, lib, buildEnv, fetchurl, gradleGen, writeText }:
 
-{ name, repositories, dependencies }:
+{ envSpec
+, pname ? null
+, version ? null
+, enableParallelBuilding ? true
+, gradleFlags ? [ "build" ]
+, gradlePackage ? null
+, ... } @ args:
 
 let
-  mkPath = artifact: with artifact; lib.concatStringsSep "/" [
-    (lib.replaceChars ["."] ["/"] artifact.groupId)
-    artifact.artifactId
-    artifact.version
-  ];
-
-  mkFilename = artifact: with artifact;
-    "${artifactId}-${version}${lib.optionalString (classifier != "") "-${classifier}"}.${extension}";
-
-  mkMavenUrls = repo: artifact:
-
-
-  mkArtifactUrl = base: artifact:
-    "${lib.removeSuffix "/" base}/${mkPath artifact}/${mkFilename artifact}";
-
-  fetchArtifact = artifact:
-  let
-    artifactPath = mkPath artifact;
-    artifactName = mkFilename artifact;
-  in stdenvNoCC.mkDerivation rec {
-    name = with artifact; lib.concatStrings [
-      (lib.replaceChars ["."] ["_"] groupId) "-"
-      (lib.replaceChars ["."] ["_"] artifactId) "-"
-      version
-      (lib.optionalString (classifier != "") "-${classifier}")
-      "-" type
-    ];
+  mkDep = depSpec: stdenv.mkDerivation {
+    inherit (depSpec) name;
 
     src = fetchurl {
-      name = mkFilename artifact;
-      urls = map (url: mkArtifactUrl url artifact) repositories;
-      inherit (artifact) sha256;
+      inherit (depSpec) urls sha256;
     };
 
     phases = "installPhase fixupPhase";
 
     installPhase = ''
-      mkdir -p $out/${artifactPath}
-      ln -s ${src} $out/${artifactPath}/${artifactName}
+      mkdir -p $out/${depSpec.path}
+      ln -s $src $out/${depSpec.path}/${depSpec.filename}
     '';
   };
 
-in
-buildEnv {
-  inherit name;
-  paths = map fetchArtifact dependencies;
-}
+  mkRepo = project: type: deps: buildEnv {
+    name = "${project}-gradle-${type}-env";
+    paths = map mkDep deps;
+  };
+
+  mkInitScript = projectSpec:
+    let
+      repos = builtins.mapAttrs (mkRepo projectSpec.name) projectSpec.dependencies;
+    in
+      writeText "init.gradle" ''
+        gradle.settingsEvaluated {
+          it.pluginManagement.repositories {
+            clear()
+            maven { url = uri("${repos.plugin}") }
+          }
+        }
+
+        gradle.projectsLoaded {
+          allprojects {
+            buildscript {
+              repositories {
+                clear()
+                maven { url = uri("${repos.buildscript}") }
+              }
+            }
+            repositories {
+              clear()
+              maven { url = uri("${repos.project}") }
+            }
+          }
+        }
+      '';
+
+  mkGradle = gradleSpec:
+    gradleGen.gradleGen {
+      inherit (gradleSpec) nativeVersion;
+
+      name = "gradle-${gradleSpec.version}-${gradleSpec.type}";
+
+      src = fetchurl {
+        inherit (gradleSpec) url sha256;
+      };
+    };
+
+  mkProjectEnv = projectSpec: {
+    inherit (projectSpec) name version;
+    initScript = mkInitScript projectSpec;
+    gradle = args.gradlePackage or mkGradle projectSpec.gradle;
+  };
+
+  gradleEnv = builtins.mapAttrs
+    (_: p: mkProjectEnv p)
+    (builtins.fromJSON (builtins.readFile envSpec));
+
+  projectEnv = gradleEnv."";
+  pname = args.pname or projectEnv.name;
+  version = args.version or projectEnv.version;
+
+in stdenv.mkDerivation (args // {
+
+  inherit pname version;
+
+  nativeBuildInputs = (args.nativeBuildInputs or []) ++ [ projectEnv.gradle ];
+
+  buildPhase = args.buildPhase or ''
+    runHook preBuild
+
+    (
+    set -x
+    env \
+      "GRADLE_USER_HOME=$(mktemp -d)" \
+      gradle --offline --no-daemon --no-build-cache \
+        --info --full-stacktrace --warning-mode=all \
+        ${lib.optionalString enableParallelBuilding "--parallel"} \
+        --init-script ${projectEnv.initScript} \
+        ${builtins.concatStringsSep " " gradleFlags}
+    )
+
+    runHook postBuild
+  '';
+
+  dontStrip = true;
+})

app/src/main/kotlin/org/nixos/gradle2nix/Env.kt

@@ -4,9 +4,11 @@ import com.squareup.moshi.JsonClass
 
 @JsonClass(generateAdapter = true)
 data class NixGradleEnv(
-    val project: String,
-    val pluginRepo: List<Dependency>,
-    val projectRepos: Map<String, List<Dependency>>
+    val name: String,
+    val version: String,
+    val path: String,
+    val gradle: DefaultGradle,
+    val dependencies: Map<String, List<Dependency>>
 )
 
 @JsonClass(generateAdapter = true)
@@ -21,12 +23,18 @@ data class Dependency(
 fun buildEnv(builds: Map<String, DefaultBuild>): Map<String, NixGradleEnv> =
     builds.mapValues { (path, build) ->
         NixGradleEnv(
-            project = path,
-            pluginRepo = buildRepo(build.pluginDependencies).values.toList(),
-            projectRepos = mapOf(
-                "buildscript" to build.rootProject.collectDependencies(DefaultProject::buildscriptDependencies).values.toList(),
-                "project" to build.rootProject.collectDependencies(DefaultProject::projectDependencies).values.toList()
-            ))
+            name = build.rootProject.name,
+            version = build.rootProject.version,
+            path = path,
+            gradle = build.gradle,
+            dependencies = mapOf(
+                "plugin" to buildRepo(build.pluginDependencies).values.toList(),
+                "buildscript" to build.rootProject.collectDependencies(DefaultProject::buildscriptDependencies)
+                    .values.toList(),
+                "project" to build.rootProject.collectDependencies(DefaultProject::projectDependencies)
+                    .values.toList()
+            )
+        )
     }
 
 private fun DefaultProject.collectDependencies(chooser: DefaultProject.() -> DefaultDependencies): Map<DefaultArtifact, Dependency> {

app/src/main/kotlin/org/nixos/gradle2nix/Main.kt

@@ -33,20 +33,20 @@ data class Config(
 class Main : CliktCommand(
     name = "gradle2nix"
 ) {
-    val wrapper: Boolean by option("--gradle-wrapper", "-w",
+    private val wrapper: Boolean by option("--gradle-wrapper", "-w",
         help = "Use the project's gradle wrapper for building")
         .flag()
 
-    val gradleVersion: String? by option("--gradle-version", "-g",
+    private val gradleVersion: String? by option("--gradle-version", "-g",
         metavar = "VERSION",
         help = "Use a specific Gradle version")
 
-    val configurations: List<String> by option("--configuration", "-c",
+    private val configurations: List<String> by option("--configuration", "-c",
         metavar = "NAME",
         help = "Add a configuration to resolve (default: all configurations)")
         .multiple()
 
-    val includes: List<File> by option("--include", "-i",
+    private val includes: List<File> by option("--include", "-i",
         metavar = "DIR",
         help = "Add an additional project to include")
         .file(exists = true, fileOkay = false, folderOkay = true, readable = true)
@@ -60,23 +60,23 @@ class Main : CliktCommand(
             }
         }
 
-    val outDir: File? by option("--out-dir", "-o",
+    private val outDir: File? by option("--out-dir", "-o",
         metavar = "DIR",
         help = "Path to write generated files (default: PROJECT-DIR)")
         .file(fileOkay = false, folderOkay = true)
 
-    val envFile: String by option("--env", "-e",
+    private val envFile: String by option("--env", "-e",
         metavar = "FILENAME",
-        help = "Name of the environment file")
-        .default("gradle-env.json")
+        help = "Prefix for environment files (.json and .nix)")
+        .default("gradle-env")
 
-    val buildSrc: Boolean by option("--build-src", "-b", help = "Include buildSrc project (default: true)")
+    private val buildSrc: Boolean by option("--build-src", "-b", help = "Include buildSrc project (default: true)")
         .flag("--no-build-src", "-nb", default = true)
 
-    val quiet: Boolean by option("--quiet", "-q", help = "Disable logging")
+    private val quiet: Boolean by option("--quiet", "-q", help = "Disable logging")
         .flag(default = false)
 
-    val projectDir: File by argument("PROJECT-DIR", help = "Path to the project root (default: .)")
+    private val projectDir: File by argument("PROJECT-DIR", help = "Path to the project root (default: .)")
         .projectDir()
         .default(File("."))
 
@@ -105,10 +105,11 @@ class Main : CliktCommand(
         val nixGradleEnv = buildEnv(models)
 
         val outDir = outDir ?: projectDir
-        val envFile = outDir.resolve(envFile)
-        log("Writing environment to $envFile")
 
-        envFile.sink().buffer().use { out ->
+        val json = outDir.resolve("$envFile.json")
+        log("Writing environment to $json")
+
+        json.sink().buffer().use { out ->
             Moshi.Builder().build()
                 .adapter<Map<String, NixGradleEnv>>(
                     Types.newParameterizedType(Map::class.java, String::class.java, NixGradleEnv::class.java)
@@ -117,6 +118,11 @@ class Main : CliktCommand(
                 .toJson(out, nixGradleEnv)
             out.flush()
         }
+
+        val nix = outDir.resolve("$envFile.nix")
+        log("Writing Nix script to $nix")
+
+        File(shareDir).resolve("gradle-env.nix").copyTo(nix, overwrite = true)
     }
 }