Allow overriding dependencies in gradle.nix

app/build.gradle.kts

@@ -34,7 +34,7 @@ application {
         "-Dslf4j.internal.verbosity=ERROR"
     )
     applicationDistribution
-        .from(configurations.named("share"))
+        .from(configurations.named("share"), files("../gradle.nix"))
         .into("share")
         .rename("plugin.*\\.jar", "plugin.jar")
 }

app/src/dist/share/gradle.nix

@@ -1,290 +0,0 @@
-# This file is generated by gradle2nix.
-#
-# Example usage (e.g. in default.nix):
-#
-#     with (import <nixpkgs> {});
-#     let
-#       buildGradle = callPackage ./gradle.nix {};
-#     in
-#       buildGradle {
-#         lockFile = ./gradle.lock;
-#
-#         src = ./.;
-#
-#         gradleFlags = [ "installDist" ];
-#
-#         installPhase = ''
-#           mkdir -p $out
-#           cp -r app/build/install/myproject $out
-#         '';
-#       }
-
-{ lib
-, stdenv
-, buildEnv
-, fetchs3
-, fetchurl
-, gradle
-, maven
-, runCommandLocal
-, symlinkJoin
-, writeText
-, writeTextDir
-}:
-
-{
-  # Path to the lockfile generated by gradle2nix (e.g. gradle.lock).
-  lockFile
-, pname ? "project"
-, version ? null
-, enableParallelBuilding ? true
-# Arguments to Gradle used to build the project in buildPhase.
-, gradleFlags ? [ "build" ]
-# Enable debugging for the Gradle build; this will cause Gradle to run a debug server
-# and wait for a JVM debugging client to attach.
-, enableDebug ? false
-# Additional code to run in the Gradle init script (init.gradle).
-, extraInit ? ""
-# Override the default JDK used to run Gradle itself.
-, buildJdk ? null
-# Override functions which fetch dependency artifacts.
-# Keys in this set are URL schemes such as "https" or "s3".
-# Values are functions which take a dependency in the form
-# `{ urls, hash }` and fetch into the Nix store. For example:
-#
-#   {
-#     s3 = { name, urls, hash }: fetchs3 {
-#       s3url = builtins.head urls;
-#       # TODO This doesn't work without patching fetchs3 to accept SRI hashes
-#       inherit name hash;
-#       region = "us-west-2";
-#       credentials = {
-#         access_key_id = "foo";
-#         secret_access_key = "bar";
-#       };
-#     };
-#   }
-, fetchers ? { }
-, ... } @ args:
-
-let
-  inherit (builtins)
-    attrValues concatStringsSep elemAt filter fromJSON getAttr hasAttr head length match
-    removeAttrs replaceStrings sort;
-
-  inherit (lib)
-    assertMsg concatMapStringsSep findFirst foldl' groupBy' hasSuffix hasPrefix last mapAttrs
-    mapAttrsToList optionalAttrs optionalString readFile removeSuffix unique versionAtLeast
-    versionOlder;
-
-  inherit (lib.strings) sanitizeDerivationName;
-
-  lockedDeps = fromJSON (readFile lockFile);
-
-  toCoordinates = id:
-    let
-      coords = builtins.split ":" id;
-    in rec {
-      group = elemAt coords 0;
-      module = elemAt coords 2;
-      version = elemAt coords 4;
-      versionParts = parseVersion version;
-    };
-
-  parseVersion = version:
-    let
-      parts = builtins.split ":" version;
-      base = elemAt parts 0;
-    in
-      {
-        inherit base;
-        exact = base;
-      }
-      // optionalAttrs (length parts >= 2) (
-        let
-          snapshot = elemAt parts 2;
-          exact = replaceStrings [ "-SNAPSHOT" ] [ "-${snapshot}" ] base;
-          parts = builtins.split "-" timestamp;
-          timestamp = findFirst (match "[0-9]{8}\.[0-9]{6}") parts;
-          buildNumber = let lastPart = last parts; in if match "[0-9]+" lastPart then lastPart else null;
-        in
-          { inherit snapshot exact timestamp buildNumber; }
-      );
-
-  fetchers' = {
-    http = fetchurl;
-    https = fetchurl;
-  } // fetchers;
-
-  # Fetch urls using the scheme for the first entry only; there isn't a
-  # straightforward way to tell Nix to try multiple fetchers in turn
-  # and short-circuit on the first successful fetch.
-  fetch = name: { url, hash }:
-    let
-      scheme = head (builtins.match "([a-z0-9+.-]+)://.*" url);
-      fetch' = getAttr scheme fetchers';
-    in
-      fetch' { inherit url hash; };
-
-  mkModule = id: artifacts:
-    let
-      coords = toCoordinates id;
-      modulePath = "${replaceStrings ["."] ["/"] coords.group}/${coords.module}/${coords.version}";
-    in
-      stdenv.mkDerivation {
-        pname = sanitizeDerivationName "${coords.group}-${coords.module}";
-        version = coords.versionParts.exact;
-
-        srcs = mapAttrsToList fetch artifacts;
-
-        dontPatch = true;
-        dontConfigure = true;
-        dontBuild = true;
-        dontFixup = true;
-        dontInstall = true;
-
-        preUnpack = ''
-          mkdir -p "$out/${modulePath}"
-        '';
-
-        unpackCmd = ''
-          cp "$curSrc" "$out/${modulePath}/$(stripHash "$curSrc")"
-        '';
-
-        sourceRoot = ".";
-
-        preferLocalBuild = true;
-        allowSubstitutes = false;
-      };
-
-  offlineRepo = symlinkJoin {
-    name = if version != null then "${pname}-${version}-gradle-repo" else "${pname}-gradle-repo";
-    paths = mapAttrsToList mkModule lockedDeps;
-  };
-
-  initScript =
-    let
-      inSettings = pred: script:
-        optionalString pred (
-          if versionAtLeast gradle.version "6.0" then ''
-            gradle.beforeSettings {
-              ${script}
-            }
-          '' else ''
-            gradle.settingsEvaluated {
-              ${script}
-            }
-          ''
-        );
-    in
-      writeText "init.gradle" ''
-        static def offlineRepo(RepositoryHandler repositories) {
-            repositories.clear()
-            repositories.mavenLocal {
-                url 'file:${offlineRepo}'
-                metadataSources {
-                    gradleMetadata()
-                    mavenPom()
-                    artifact()
-                }
-            }
-        }
-
-        ${inSettings (versionAtLeast gradle.version "6.0") ''
-          offlineRepo(it.buildscript.repositories)
-        ''}
-
-        ${inSettings true ''
-            offlineRepo(it.pluginManagement.repositories)
-        ''}
-
-        gradle.projectsLoaded {
-            allprojects {
-                buildscript {
-                    offlineRepo(repositories)
-                }
-            }
-        }
-
-        ${if versionAtLeast gradle.version "6.8"
-          then ''
-            gradle.beforeSettings {
-                it.dependencyResolutionManagement {
-                    offlineRepo(repositories)
-                    repositoriesMode.set(RepositoriesMode.PREFER_SETTINGS)
-                }
-            }
-          ''
-          else ''
-            gradle.projectsLoaded {
-                allprojects {
-                    offlineRepo(repositories)
-                }
-            }
-          ''
-        }
-
-        ${extraInit}
-      '';
-
-  buildProject = flags: ''
-    gradle --offline --no-daemon --no-build-cache \
-      --info --full-stacktrace --warning-mode=all \
-      --no-configuration-cache \
-      -Dmaven.repo.local=${offlineRepo} \
-      ${optionalString enableParallelBuilding "--parallel"} \
-      ${optionalString enableDebug "-Dorg.gradle.debug=true"} \
-      ${optionalString (buildJdk != null) "-Dorg.gradle.java.home=${buildJdk.home}"} \
-      --init-script ${initScript} \
-      ${concatStringsSep " " flags}
-  '';
-
-in stdenv.mkDerivation ({
-
-  dontStrip = true;
-
-  nativeBuildInputs = (args.nativeBuildInputs or []) ++ [ gradle ];
-
-  buildPhase = args.buildPhase or ''
-    runHook preBuild
-
-    (
-    set -eux
-
-    ${optionalString (versionOlder gradle.version "8.0") ''
-      # Work around https://github.com/gradle/gradle/issues/1055
-      TMPHOME="$(mktemp -d)"
-      mkdir -p "$TMPHOME/init.d"
-      export GRADLE_USER_HOME="$TMPHOME"
-      cp ${initScript} $TMPHOME/
-    ''}
-
-    gradle --offline --no-daemon --no-build-cache \
-      --info --full-stacktrace --warning-mode=all \
-      --no-configuration-cache --console=plain \
-      -Dmaven.repo.local=${offlineRepo} \
-      ${optionalString enableParallelBuilding "--parallel"} \
-      ${optionalString enableDebug "-Dorg.gradle.debug=true"} \
-      ${optionalString (buildJdk != null) "-Dorg.gradle.java.home=${buildJdk.home}"} \
-      --init-script ${initScript} \
-      ${concatStringsSep " " gradleFlags}
-    )
-
-    runHook postBuild
-  '';
-
-  passthru = (args.passthru or {}) // {
-    inherit offlineRepo;
-  };
-
-} // (removeAttrs args [
-  "nativeBuildInputs"
-  "passthru"
-  "lockFile"
-  "gradleFlags"
-  "gradle"
-  "enableDebug"
-  "extraInit"
-  "buildJdk"
-  "fetchers"
-]))

default.nix

@@ -33,8 +33,18 @@ let
     '';
 
     passthru = {
+      build = buildGradle;
       plugin = "${gradle2nix}/share/plugin.jar";
     };
+
+    meta = with lib; {
+      inherit (gradle.meta) platforms;
+      description = "Wrap Gradle builds with Nix";
+      homepage = "https://github.com/tadfisher/gradle2nix";
+      license = licenses.asl20;
+      maintainers = with maintainers; [ tadfisher ];
+      mainProgram = "gradle2nix";
+    };
   };
 
 in gradle2nix

flake.lock

@@ -1,19 +1,5 @@
 {
   "nodes": {
-    "flake-compat": {
-      "locked": {
-        "lastModified": 1696426674,
-        "narHash": "sha256-kvjfFW7WAETZlt09AgDn1MrtKzP7t90Vf7vypd3OL1U=",
-        "rev": "0f9255e01c2351cc7d116c072cb317785dd33b33",
-        "revCount": 57,
-        "type": "tarball",
-        "url": "https://api.flakehub.com/f/pinned/edolstra/flake-compat/1.0.1/018afb31-abd1-7bff-a5e4-cff7e18efb7a/source.tar.gz"
-      },
-      "original": {
-        "type": "tarball",
-        "url": "https://flakehub.com/f/edolstra/flake-compat/1.tar.gz"
-      }
-    },
     "flake-utils": {
       "inputs": {
         "systems": "systems"
@@ -50,7 +36,6 @@
     },
     "root": {
       "inputs": {
-        "flake-compat": "flake-compat",
         "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs"
       }

flake.nix

@@ -2,7 +2,6 @@
   description = "Wrap Gradle builds with Nix";
 
   inputs = {
-    flake-compat.url = "https://flakehub.com/f/edolstra/flake-compat/1.tar.gz";
     flake-utils.url = "github:numtide/flake-utils";
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable-small";
   };
@@ -13,7 +12,7 @@
         pkgs = nixpkgs.legacyPackages.${system};
 
       in {
-        packages.default = pkgs.callPackage ./gradle2nix.nix {};
+        packages.default = pkgs.callPackage ./default.nix {};
 
         apps.default = {
           type = "app";

gradle.nix

@@ -32,16 +32,20 @@
 , writeTextDir
 }:
 
+let defaultGradle = gradle; in
+
 {
   # Path to the lockfile generated by gradle2nix (e.g. gradle.lock).
-  lockFile
+  lockFile ? null
 , pname ? "project"
 , version ? null
 , enableParallelBuilding ? true
+# The Gradle package to use. Default is 'pkgs.gradle'.
+, gradle ? defaultGradle
 # Arguments to Gradle used to build the project in buildPhase.
 , gradleFlags ? [ "build" ]
-# Enable debugging for the Gradle build; this will cause Gradle to run a debug server
-# and wait for a JVM debugging client to attach.
+# Enable debugging for the Gradle build; this will cause Gradle to run
+# a debug server and wait for a JVM debugging client to attach.
 , enableDebug ? false
 # Additional code to run in the Gradle init script (init.gradle).
 , extraInit ? ""
@@ -65,52 +69,79 @@
 #     };
 #   }
 , fetchers ? { }
+# Overlays for dependencies in the offline Maven repository.
+#
+# Acceps an attrset of dependencies (usually parsed from 'lockFile'), and produces an attrset
+# containing dependencies to merge into the final set.
+#
+# The attrset is of the form:
+#
+#   {
+#      "${group}:${module}:${version}" = <derivation>;
+#      # ...
+#   }
+#
+# A dependency derivation unpacks multiple source files into a single Maven-style directory named
+# "${out}/${groupPath}/${module}/${version}/", where 'groupPath' is the dependency group ID with dot
+# characters ('.') replaced by the path separator ('/').
+#
+# Examples:
+#
+# 1. Add or replace a dependency with a single JAR file:
+#
+#    (_: {
+#      "com.squareup.okio:okio:3.9.0" = fetchurl {
+#        url = "https://repo.maven.apache.org/maven2/com/squareup/okio/okio/3.9.0/okio-3.9.0.jar";
+#        hash = "...";
+#        downloadToTemmp = true;
+#        postFetch = "install -Dt $out/com/squareup/okio/okio/3.9.0/ $downloadedFile"
+#      };
+#    })
+#
+# 2. Remove a dependency entirely:
+#
+#    # This works because the result is filtered for values that are derivations.
+#    (_: {
+#      "org.apache.log4j:core:2.23.1" = null;
+#    })
+, overlays ? []
 , ... } @ args:
 
 let
   inherit (builtins)
-    attrValues concatStringsSep elemAt filter fromJSON getAttr hasAttr head length match
-    removeAttrs replaceStrings sort;
+    attrValues concatStringsSep elemAt filter fromJSON getAttr head length mapAttrs removeAttrs
+    replaceStrings;
 
   inherit (lib)
-    assertMsg concatMapStringsSep findFirst foldl' groupBy' hasSuffix hasPrefix last mapAttrs
-    mapAttrsToList optionalAttrs optionalString readFile removeSuffix unique versionAtLeast
-    versionOlder;
+    mapAttrsToList optionalString readFile versionAtLeast versionOlder;
 
   inherit (lib.strings) sanitizeDerivationName;
 
-  lockedDeps = fromJSON (readFile lockFile);
-
   toCoordinates = id:
     let
       coords = builtins.split ":" id;
+
+      parseVersion = version:
+        let
+          parts = builtins.split ":" version;
+          base = elemAt parts 0;
+        in
+          if length parts >= 2
+          then
+            let
+              snapshot = elemAt parts 2;
+            in
+              replaceStrings [ "-SNAPSHOT" ] [ "-${snapshot}" ] base
+          else
+            base;
+
     in rec {
       group = elemAt coords 0;
       module = elemAt coords 2;
       version = elemAt coords 4;
-      versionParts = parseVersion version;
+      uniqueVersion = parseVersion version;
     };
 
-  parseVersion = version:
-    let
-      parts = builtins.split ":" version;
-      base = elemAt parts 0;
-    in
-      {
-        inherit base;
-        exact = base;
-      }
-      // optionalAttrs (length parts >= 2) (
-        let
-          snapshot = elemAt parts 2;
-          exact = replaceStrings [ "-SNAPSHOT" ] [ "-${snapshot}" ] base;
-          parts = builtins.split "-" timestamp;
-          timestamp = findFirst (match "[0-9]{8}\.[0-9]{6}") parts;
-          buildNumber = let lastPart = last parts; in if match "[0-9]+" lastPart then lastPart else null;
-        in
-          { inherit snapshot exact timestamp buildNumber; }
-      );
-
   fetchers' = {
     http = fetchurl;
     https = fetchurl;
@@ -133,7 +164,7 @@ let
     in
       stdenv.mkDerivation {
         pname = sanitizeDerivationName "${coords.group}-${coords.module}";
-        version = coords.versionParts.exact;
+        version = coords.uniqueVersion;
 
         srcs = mapAttrsToList fetch artifacts;
 
@@ -157,9 +188,30 @@ let
         allowSubstitutes = false;
       };
 
+  # Intermediate dependency spec.
+  #
+  # We want to allow overriding dependencies via the 'dependencies' function,
+  # so we pass an intermediate set that maps each Maven coordinate to the
+  # derivation created with 'mkModule'. This allows users extra flexibility
+  # to do things like patching native libraries with patchelf or replacing
+  # artifacts entirely.
+  lockedDependencies = final: if lockFile == null then {} else
+    let
+      lockedDependencySpecs = fromJSON (readFile lockFile);
+    in mapAttrs mkModule lockedDependencySpecs;
+
+
+  finalDependencies =
+    let
+      composedExtension = lib.composeManyExtensions overlays;
+      extended = lib.extends composedExtension lockedDependencies;
+      fixed = lib.fix extended;
+    in
+      filter lib.isDerivation (attrValues fixed);
+
   offlineRepo = symlinkJoin {
     name = if version != null then "${pname}-${version}-gradle-repo" else "${pname}-gradle-repo";
-    paths = mapAttrsToList mkModule lockedDeps;
+    paths = finalDependencies;
   };
 
   initScript =
@@ -227,64 +279,53 @@ let
         ${extraInit}
       '';
 
-  buildProject = flags: ''
-    gradle --offline --no-daemon --no-build-cache \
-      --info --full-stacktrace --warning-mode=all \
-      --no-configuration-cache \
-      -Dmaven.repo.local=${offlineRepo} \
-      ${optionalString enableParallelBuilding "--parallel"} \
-      ${optionalString enableDebug "-Dorg.gradle.debug=true"} \
-      ${optionalString (buildJdk != null) "-Dorg.gradle.java.home=${buildJdk.home}"} \
-      --init-script ${initScript} \
-      ${concatStringsSep " " flags}
-  '';
 
-in stdenv.mkDerivation ({
+  buildGradle = stdenv.mkDerivation (finalAttrs: {
 
-  dontStrip = true;
+    inherit buildJdk enableParallelBuilding enableDebug gradle gradleFlags pname version;
 
-  nativeBuildInputs = (args.nativeBuildInputs or []) ++ [ gradle ];
+    dontStrip = true;
 
-  buildPhase = args.buildPhase or ''
-    runHook preBuild
+    nativeBuildInputs = [ finalAttrs.gradle ]
+                        ++ lib.optional (finalAttrs.buildJdk != null) finalAttrs.buildJdk;
 
-    (
-    set -eux
+    buildPhase = ''
+      runHook preBuild
 
-    ${optionalString (versionOlder gradle.version "8.0") ''
-      # Work around https://github.com/gradle/gradle/issues/1055
-      TMPHOME="$(mktemp -d)"
-      mkdir -p "$TMPHOME/init.d"
-      export GRADLE_USER_HOME="$TMPHOME"
-      cp ${initScript} $TMPHOME/
-    ''}
+      (
+      set -eux
 
-    gradle --offline --no-daemon --no-build-cache \
-      --info --full-stacktrace --warning-mode=all \
-      --no-configuration-cache --console=plain \
-      -Dmaven.repo.local=${offlineRepo} \
-      ${optionalString enableParallelBuilding "--parallel"} \
-      ${optionalString enableDebug "-Dorg.gradle.debug=true"} \
-      ${optionalString (buildJdk != null) "-Dorg.gradle.java.home=${buildJdk.home}"} \
-      --init-script ${initScript} \
-      ${concatStringsSep " " gradleFlags}
-    )
+      ${optionalString (versionOlder finalAttrs.gradle.version "8.0") ''
+        # Work around https://github.com/gradle/gradle/issues/1055
+        TMPHOME="$(mktemp -d)"
+        mkdir -p "$TMPHOME/init.d"
+        export GRADLE_USER_HOME="$TMPHOME"
+        cp ${initScript} $TMPHOME/
+      ''}
 
-    runHook postBuild
-  '';
+      gradle --offline --no-daemon --no-build-cache \
+        --info --full-stacktrace --warning-mode=all \
+        --no-configuration-cache --console=plain \
+        -Dmaven.repo.local=${offlineRepo} \
+        ${optionalString finalAttrs.enableParallelBuilding "--parallel"} \
+        ${optionalString finalAttrs.enableDebug "-Dorg.gradle.debug=true"} \
+        ${optionalString (finalAttrs.buildJdk != null) "-Dorg.gradle.java.home=${finalAttrs.buildJdk.home}"} \
+        --init-script ${initScript} \
+        ${concatStringsSep " " finalAttrs.gradleFlags}
+      )
 
-  passthru = (args.passthru or {}) // {
-    inherit offlineRepo;
-  };
+      runHook postBuild
+    '';
 
-} // (removeAttrs args [
-  "nativeBuildInputs"
-  "passthru"
-  "lockFile"
-  "gradleFlags"
-  "gradle"
-  "enableDebug"
-  "extraInit"
-  "buildJdk"
-  "fetchers"
-]))
+    passthru = {
+      inherit offlineRepo;
+    };
+  } // removeAttrs args [
+    "lockFile"
+    "extraInit"
+    "fetchers"
+    "overlays"
+  ]);
+
+in
+buildGradle

gradle2nix.nix

@@ -1,46 +0,0 @@
-{ lib
-, callPackage
-, gradle
-}:
-
-let
-  buildGradle = callPackage ./gradle.nix {
-    inherit gradle;
-  };
-in
-buildGradle {
-  pname = "gradle2nix";
-  version = "2.0.0";
-  lockFile = ./gradle.lock;
-
-  src = lib.cleanSourceWith {
-      filter = lib.cleanSourceFilter;
-      src = lib.cleanSourceWith {
-          filter = path: type: let baseName = builtins.baseNameOf path; in !(
-          (type == "directory" && (
-                  baseName == "build" ||
-                          baseName == ".idea" ||
-                          baseName == ".gradle"
-                  )) ||
-                  (lib.hasSuffix ".iml" baseName)
-          );
-          src = ./.;
-      };
-  };
-
-  gradleFlags = [ "installDist" ];
-
-  installPhase = ''
-    mkdir -p $out
-    cp -r app/build/install/gradle2nix/* $out/
-  '';
-
-  meta = with lib; {
-    inherit (gradle.meta) platforms;
-    description = "Wrap Gradle builds with Nix";
-    homepage = "https://github.com/tadfisher/gradle2nix";
-    license = licenses.asl20;
-    maintainers = with maintainers; [ tadfisher ];
-    mainProgram = "gradle2nix";
-  };
-}