When check_mutable_updates: true is set on a remote, expired user-defined
mutable files are revalidated before re-downloading:
- On expiry a conditional HEAD is sent with If-None-Match / If-Modified-Since
- 304 Not Modified: TTL is refreshed in Redis, S3 cache is untouched
- 200 / no conditional support: cache is invalidated and file re-downloaded
- Network error: safe fallback — assume changed, re-download
ETag and Last-Modified from upstream responses are stored in Redis under
mutable:meta:<remote>:<hash> (no expiry, cleaned up on re-download or
cache flush). The flag only applies to user-configured mutable_patterns;
built-in package-type defaults (APKINDEX, repomd.xml, Docker manifests)
are always re-fetched unconditionally.
cache/flush also clears mutable:meta:* keys alongside index:* keys.
Replace the include_patterns/index_patterns split with a clearer
immutable_patterns/mutable_patterns model:
- immutable_patterns: artifacts cached indefinitely (no TTL)
- mutable_patterns: artifacts that expire and are re-fetched after
cache.mutable_ttl seconds (replaces cache.index_ttl)
_PACKAGE_INDEX_PATTERNS renamed to _PACKAGE_MUTABLE_PATTERNS; all
built-in package-type index patterns (APKINDEX, repomd, manifests, etc.)
default to the remote's mutable_ttl (default 1 hour).
cache.file_ttl renamed to cache.immutable_ttl for consistency.
Adds github-archive remote to remotes.yaml as a worked example showing
tag archives as immutable and branch archives as mutable (1-day TTL).
docker-compose.yml: fix VERSION=dev → 2.2.2.dev0 (valid PEP 440),
add :z SELinux label to volume mounts.