The rpm virtual's merge cache, singleflight and two-generation retention are hard-wired to RPMRepo, so other merged index types (deb next) can't reuse them.
- add a mergedRepo interface (index + referenced files) implemented by RPMRepo
- key the merge cache by type-scoped string and serve files from both retained generations via cachedFile
- extract parallel fail-closed member fetching into a generic fetchMembers
- add tests for generation retention and per-key isolation
Reviewed-on: #147
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>
Virtual repos only merge helm and pypi, so several rpm repos (e.g. many github_rpm remotes) cannot be served as one yum repo.
- merge member primary/filelists/other into one repodata set; member order wins duplicate NEVRAs
- read member repodata through local, github_rpm and proxied remote paths
- prefix package locations (incl. xml:base under a member upstream) with the member name and 302 them to the member route
- reject absolute and dot-segment member paths; escape the redirect and keep its query
- return 502 when any member's repodata is unavailable
- reuse each virtual's merge for 60s behind singleflight; serve data files from its current and previous merge (per replica)
- add merger/engine unit tests and a dockerised dnf e2e case
Reviewed-on: #131
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>
unkin-agent