From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Tue, 23 Jul 2024 20:59:22 +0000 (+0200)
Subject: Drop uid/gid from cache manifest
X-Git-Tag: v24~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=36dea6cbfba7db647c7cdf4a5600c5aa5524cf60;p=thirdparty%2Fmkosi.git

Drop uid/gid from cache manifest

This does not work as we call have_cache() to determine whether
we need to clean the tools tree or not and when running as root to
boot after building an image the UID/GID will differ and the tools
tree will incorrectly be considered out of date.

Let's move the UID/GID check out of have_cache() and into reuse_cache()
instead. reuse_cache() always runs after we've already potentially
unshared the user namespace and become root, so checking the owner of
the cache directory against the current UID should be a valid check
there.
---

diff --git a/mkosi/__init__.py b/mkosi/__init__.py
index a987a6c6a..36a9b470c 100644
--- a/mkosi/__init__.py
+++ b/mkosi/__init__.py
@@ -3332,6 +3332,9 @@ def reuse_cache(context: Context) -> bool:
 
     final, build, _ = cache_tree_paths(context.config)
 
+    if final.stat().st_uid != os.getuid():
+        return False
+
     with complete_step("Copying cached trees"):
         copy_tree(
             final, context.root,
diff --git a/mkosi/config.py b/mkosi/config.py
index 193f95702..ff21cc111 100644
--- a/mkosi/config.py
+++ b/mkosi/config.py
@@ -1363,8 +1363,6 @@ class Args:
         j = cls._load_json(s)
         return dataclasses.replace(cls.default(), **j)
 
-CACHE_UID = os.getuid()
-CACHE_GID = os.getgid()
 
 PACKAGE_GLOBS = (
     "*.rpm",
@@ -1657,8 +1655,6 @@ class Config:
 
     def cache_manifest(self) -> dict[str, Any]:
         return {
-            "uid": CACHE_UID,
-            "gid": CACHE_GID,
             "distribution": self.distribution,
             "release": self.release,
             "mirror": self.mirror,