Optionally save json manifest to /usr/lib/os-manifest

If json manifest is requested and metadata would not be cleaned due to
CleanPackageMetadata=, write the manifest to the OS image under the same
condition as when os-release would be written (i.e. not sysext, confext,
addon, or overlay).

Author: jcgl17

mkosi/__init__.py

@@ -89,7 +89,7 @@
 from mkosi.context import Context
 from mkosi.distribution import Distribution, detect_distribution
 from mkosi.documentation import show_docs
-from mkosi.installer import clean_package_manager_metadata
+from mkosi.installer import clean_package_manager_metadata, package_manager_metadata_to_clean
 from mkosi.kmod import (
     filter_devicetrees,
     gen_required_kernel_modules,
@@ -2542,6 +2542,23 @@ def save_manifest(context: Context, manifest: Optional[Manifest]) -> None:
                     manifest.write_package_report(f)
 
 
+def save_manifest_to_image(context: Context, manifest: Optional[Manifest]) -> None:
+    """Write manifest to /usr/lib/os-manifest in the image"""
+    if package_manager_metadata_to_clean(context):
+        return
+
+    if not manifest:
+        return
+
+    if context.config.overlay or context.config.output_format.is_extension_image():
+        return
+
+    if ManifestFormat.json in context.config.manifest_format and manifest.has_data():
+        osmanifest = context.root / "usr/lib/os-manifest"
+        with osmanifest.open("w") as f:
+            manifest.write_json(f)
+
+
 def print_output_size(path: Path) -> None:
     if path.is_dir():
         log_step(f"{path} size is " + format_bytes(dir_size(path)) + ".")
@@ -3947,6 +3964,7 @@ def build_image(context: Context) -> None:
 
         if manifest:
             manifest.record_packages()
+        save_manifest_to_image(context, manifest)
         save_manifest(context, manifest)
 
         run_selinux_relabel(context)

mkosi/installer/__init__.py

@@ -201,16 +201,24 @@ def clean_package_manager_metadata(context: Context) -> None:
     Try them all regardless of the distro: metadata is only removed if
     the package manager is not present in the image.
     """
+    pathsToClean = package_manager_metadata_to_clean(context)
+    rmtree(*pathsToClean, sandbox=context.sandbox)
+
+
+def package_manager_metadata_to_clean(context: Context) -> list[Path]:
+    """
+    Identifies any metadata paths that should be removed
+    """
     subdir = context.config.distribution.installer.package_manager(context.config).subdir(context.config)
 
     if context.config.clean_package_metadata == ConfigFeature.disabled:
-        return
+        return []
 
     if context.config.clean_package_metadata == ConfigFeature.auto and context.config.output_format in (
         OutputFormat.directory,
         OutputFormat.tar,
     ):
-        return
+        return []
 
     # If cleaning is not explicitly requested, keep the repository metadata if we're building a directory or
     # tar image (which are often used as a base tree for extension images and thus should retain package
@@ -219,7 +227,7 @@ def clean_package_manager_metadata(context: Context) -> None:
     executable = context.config.distribution.installer.package_manager(context.config).executable(
         context.config
     )
-    remove = []
+    pathsToClean = []
 
     for tool, paths in (
         ("rpm",      ["var/lib/rpm", "usr/lib/sysimage/rpm"]),
@@ -230,6 +238,6 @@ def clean_package_manager_metadata(context: Context) -> None:
         if context.config.clean_package_metadata == ConfigFeature.enabled or not find_binary(
             tool, root=context.root
         ):
-            remove += [context.root / p for p in paths if (context.root / p).exists()]
+            pathsToClean += [context.root / p for p in paths if (context.root / p).exists()]
 
-    rmtree(*remove, sandbox=context.sandbox)
+    return pathsToClean

mkosi/resources/man/mkosi.1.md

@@ -623,6 +623,13 @@ boolean argument: either `1`, `yes`, or `true` to enable, or `0`, `no`,
     text format designed for diffing). By default no manifest is
     generated.
 
+    If a `json` manifest is generated, it is also written to
+    `/usr/lib/os-manifest` inside the image when all of these are true:
+
+      1. Metadata is not removed by `CleanPackageMetadata=`
+      2. `Format=` is not `sysext`, `confext`, or `addon`
+      3. `Overlay=` is not set
+
 `Output=`, `--output=`, `-o`
 :   Name to use for the generated output image file or directory. Defaults
     to `image` or, if `ImageId=` is specified, it is used as the default