normalize mtime

Co-authored-by: Malte Poll <mp@edgeless.systems>
Signed-off-by: Paul Meyer <49727155+katexochen@users.noreply.github.com>

mkosi/__init__.py

@@ -21,7 +21,7 @@
 from pathlib import Path
 from typing import Any, ContextManager, Mapping, Optional, TextIO, Union
 
-from mkosi.archive import extract_tar, make_cpio, make_tar
+from mkosi.archive import extract_tar, make_cpio, make_tar, normalize_mtime
 from mkosi.config import (
     BiosBootloader,
     Bootloader,
@@ -934,6 +934,7 @@ def build_initrd(state: MkosiState) -> Path:
         "--make-initrd", "yes",
         "--bootable", "no",
         "--manifest-format", "",
+        *([f"--environment=SOURCE_DATE_EPOCH={state.config.environment['SOURCE_DATE_EPOCH']}"] if "SOURCE_DATE_EPOCH" in state.config.environment else []),
         *(["--locale", state.config.locale] if state.config.locale else []),
         *(["--locale-messages", state.config.locale_messages] if state.config.locale_messages else []),
         *(["--keymap", state.config.keymap] if state.config.keymap else []),
@@ -962,6 +963,7 @@ def build_kernel_modules_initrd(state: MkosiState, kver: str) -> Path:
 
     make_cpio(
         state.root, kmods,
+        state.config.environment.get("SOURCE_DATE_EPOCH"),
         gen_required_kernel_modules(
             state.root, kver,
             state.config.kernel_modules_initrd_include,
@@ -1624,6 +1626,8 @@ def make_image(state: MkosiState, skip: Sequence[str] = [], split: bool = False)
     if not state.config.output_format == OutputFormat.disk:
         return []
 
+    normalize_mtime(state.root, state.config.environment.get("SOURCE_DATE_EPOCH"))
+
     cmdline: list[PathString] = [
         "systemd-repart",
         "--empty=allow",
@@ -1821,11 +1825,13 @@ def build_image(args: MkosiArgs, config: MkosiConfig) -> None:
         install_grub_bios(state, partitions)
         make_image(state, split=True)
 
+        source_date_epoch = state.config.environment.get("SOURCE_DATE_EPOCH")
         if state.config.output_format == OutputFormat.tar:
-            make_tar(state.root, state.staging / state.config.output_with_format)
+            make_tar(state.root, state.staging / state.config.output_with_format, source_date_epoch)
         elif state.config.output_format == OutputFormat.cpio:
-            make_cpio(state.root, state.staging / state.config.output_with_format)
+            make_cpio(state.root, state.staging / state.config.output_with_format, source_date_epoch)
         elif state.config.output_format == OutputFormat.directory:
+            normalize_mtime(state.root, source_date_epoch)
             state.root.rename(state.staging / state.config.output_with_format)
 
         maybe_compress(state.config, state.config.compress_output,

mkosi/archive.py

@@ -6,7 +6,7 @@
 from pathlib import Path
 from typing import Optional
 
-from mkosi.log import log_step
+from mkosi.log import complete_step, die, log_step
 from mkosi.run import bwrap, finalize_passwd_mounts
 
 
@@ -36,8 +36,9 @@ def tar_exclude_apivfs_tmp() -> list[str]:
     ]
 
 
-def make_tar(src: Path, dst: Path) -> None:
+def make_tar(src: Path, dst: Path, source_date_epoch: Optional[str]) -> None:
     log_step(f"Creating tar archive {dst}…")
+    normalize_mtime(src, source_date_epoch)
     bwrap(
         [
             tar_binary(),
@@ -82,11 +83,12 @@ def extract_tar(src: Path, dst: Path, log: bool = True) -> None:
     )
 
 
-def make_cpio(src: Path, dst: Path, files: Optional[Iterable[Path]] = None) -> None:
+def make_cpio(src: Path, dst: Path, source_date_epoch: Optional[str], files: Optional[Iterable[Path]] = None) -> None:
     if not files:
         files = src.rglob("*")
 
     log_step(f"Creating cpio archive {dst}…")
+    normalize_mtime(src, source_date_epoch)
     bwrap(
         [
             cpio_binary(),
@@ -102,3 +104,19 @@ def make_cpio(src: Path, dst: Path, files: Optional[Iterable[Path]] = None) -> N
         # Make sure tar uses user/group information from the root directory instead of the host.
         options=finalize_passwd_mounts(dst),
     )
+
+
+def normalize_mtime(root: Path, source_date_epoch: Optional[str]) -> None:
+    if source_date_epoch is None:
+        return
+
+    try:
+        mtime_epoch = int(source_date_epoch)
+    except ValueError:
+        die(f"SOURCE_DATE_EPOCH={source_date_epoch} is not a valid integer")
+    if mtime_epoch < 0:
+        die(f"SOURCE_DATE_EPOCH={source_date_epoch} is negative")
+
+    with complete_step("Normalizing mtime"):
+        for p in root.rglob("*"):
+            os.utime(p, (mtime_epoch, mtime_epoch), follow_symlinks=False)