With the pkg-cache BuildKit mirror on, `FROM almalinux/10-base` was resolved
by tag through the cache, so a compromised cache could substitute the image.
Each job using the mirror now looks up the base tag's digest DIRECTLY at
registry-1.docker.io (.gitea/scripts/resolve-base-image.sh, HTTPS, HEAD on
the manifest, regex-validated) and builds FROM image@sha256:... via the
BASE_IMAGE build-arg, so the mirror can only serve content-addressed blobs.
If the lookup fails, the mirror is NOT used for that job and the tag is pulled
straight from Docker Hub. The digest is resolved every run (no manual bumps);
local builds default to the tag.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
shadowdaoandClaude Opus 5.5
d1547f3418