1 files changed, 59 insertions, 26 deletions
diff --git a/nixos/modules/image/repart-image.nix b/nixos/modules/image/repart-image.nix
index 5ae523c43f58..83e766268cf0 100644
--- a/nixos/modules/image/repart-image.nix
+++ b/nixos/modules/image/repart-image.nix
@@ -2,8 +2,8 @@
 # NixOS module that can be imported.
 
 { lib
+, stdenvNoCC
 , runCommand
-, runCommandLocal
 , python3
 , black
 , ruff
@@ -26,15 +26,18 @@
 , xz
 
   # arguments
+, name
+, version
 , imageFileBasename
 , compression
 , fileSystems
-, partitions
+, partitionsJSON
 , split
 , seed
 , definitionsDirectory
 , sectorSize
 , mkfsEnv ? {}
+, createEmpty ? true
 }:
 
 let
@@ -52,11 +55,6 @@ let
     mypy --strict $out
   '';
 
-  amendedRepartDefinitions = runCommandLocal "amended-repart.d" {} ''
-    definitions=$(${amendRepartDefinitions} ${partitions} ${definitionsDirectory})
-    cp -r $definitions $out
-  '';
-
   fileSystemToolMapping = {
     "vfat" = [ dosfstools mtools ];
     "ext4" = [ e2fsprogs.bin ];
@@ -78,53 +76,88 @@ let
     "xz" = "xz --keep --verbose --threads=0 -${toString compression.level}";
   }."${compression.algorithm}";
 in
-
-runCommand imageFileBasename
-{
+  stdenvNoCC.mkDerivation (finalAttrs:
+  (if (version != null)
+  then { pname = name; inherit version; }
+  else { inherit name;  }
+  ) // {
   __structuredAttrs = true;
 
   nativeBuildInputs = [
     systemd
     fakeroot
     util-linux
+  ] ++ lib.optionals (compression.enable) [
     compressionPkg
   ] ++ fileSystemTools;
 
   env = mkfsEnv;
 
+  inherit partitionsJSON definitionsDirectory;
+
+  # relative path to the repart definitions that are read by systemd-repart
+  finalRepartDefinitions = "repart.d";
+
   systemdRepartFlags = [
     "--dry-run=no"
-    "--empty=create"
     "--size=auto"
     "--seed=${seed}"
-    "--definitions=${amendedRepartDefinitions}"
+    "--definitions=${finalAttrs.finalRepartDefinitions}"
     "--split=${lib.boolToString split}"
     "--json=pretty"
+  ] ++ lib.optionals createEmpty [
+    "--empty=create"
   ] ++ lib.optionals (sectorSize != null) [
     "--sector-size=${toString sectorSize}"
   ];
 
-  passthru = {
-    inherit amendRepartDefinitions amendedRepartDefinitions;
-  };
-} ''
-  mkdir -p $out
-  cd $out
+  dontUnpack = true;
+  dontConfigure = true;
+  doCheck = false;
+
+  patchPhase = ''
+    runHook prePatch
+
+    amendedRepartDefinitionsDir=$(${amendRepartDefinitions} $partitionsJSON $definitionsDirectory)
+    ln -vs $amendedRepartDefinitionsDir $finalRepartDefinitions
 
-  echo "Building image with systemd-repart..."
-  unshare --map-root-user fakeroot systemd-repart \
-    ''${systemdRepartFlags[@]} \
-    ${imageFileBasename}.raw \
-    | tee repart-output.json
+    runHook postPatch
+  '';
+
+  buildPhase = ''
+    runHook preBuild
+
+    echo "Building image with systemd-repart..."
+    unshare --map-root-user fakeroot systemd-repart \
+      ''${systemdRepartFlags[@]} \
+      ${imageFileBasename}.raw \
+      | tee repart-output.json
+
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
 
+    mkdir -p $out
+  ''
   # Compression is implemented in the same derivation as opposed to in a
   # separate derivation to allow users to save disk space. Disk images are
   # already very space intensive so we want to allow users to mitigate this.
-  if ${lib.boolToString compression.enable}; then
+  + lib.optionalString compression.enable
+  ''
     for f in ${imageFileBasename}*; do
       echo "Compressing $f with ${compression.algorithm}..."
       # Keep the original file when compressing and only delete it afterwards
       ${compressionCommand} $f && rm $f
     done
-  fi
-''
+  '' + ''
+    mv -v repart-output.json ${imageFileBasename}* $out
+
+    runHook postInstall
+  '';
+
+  passthru = {
+    inherit amendRepartDefinitions;
+  };
+})