On a cache miss the proxy stored the whole artifact before sending any of
it, so clients with an idle timeout gave up on large artifacts: git-lfs
after 30 seconds, pacman after 10. The caller that starts a shared fetch
now gets the bytes as they arrive while they are stored; requests joining
the fetch, HEAD and range requests still wait for the stored copy.
The client's copy is checked against the upstream's digest as it is read,
and a mismatch aborts the response before it completes. A client going
away leaves the copy to storage running. A storage error leaves the
client's copy running: the client gets the artifact, and the failure is
logged at error level and counted in proxy_artifacts_served_uncached_total.
A block-mode scanner has to see the whole artifact first, so with one
configured for the ecosystem a miss is handled as before.
Package files outside Hashed/, such as All/{name}-{version}.pkg from
repositories built without pkg repo --hash and the bootstrap
Latest/pkg.pkg, were relayed without any checks. They are still passed
through uncached, since their names can be reused for rebuilds, but a
versioned name is now checked against the denylist first, and while a
scanner covers freebsd they are refused, because only cached artifacts
can be scanned.
- Failure recorders take a FailureDetail: PURL, filename, URL, storage path, error
- Keep the last 20 failures per counter series in memory, reset on restart
- Strip userinfo, query and fragment from URLs, including those inside error text
- Pass the detail from upstream, storage, integrity, health probe and scan call sites
- Package names and URLs stay out of Prometheus labels
Runs fetched artifacts through pluggable external scanners after they're
staged in storage but before they're committed to the cache DB, so a
block verdict deletes the object instead of ever exposing it to a
client. Scanners pull the staged bytes themselves via a short-lived
HMAC-signed internal route rather than the proxy pushing bytes to them,
keeping the mechanism storage-backend-agnostic and avoiding uploading
potentially huge artifacts through the proxy's own egress.
Hardening baked in from the start: the internal scan-fetch route is
gated both at router-mount time and in the handler so it's inert
whenever scanning is disabled or unsigned; the signing key is mandatory
whenever scanning is enabled, enforced directly in scanner.NewGroup
rather than relying on callers to invoke config validation; the scan
call and the delete-on-block cleanup both run on a context detached
from the client's, so a client disconnecting mid-scan can't be mistaken
for a scanner failure, doesn't cause a legitimate artifact to be
deleted, and doesn't leave a genuinely blocked artifact's bytes
orphaned in storage; and scanner infrastructure errors (connection
failures, internal hostnames) are never forwarded verbatim to anonymous
clients, only a generic message. The scan-error metric also correctly
distinguishes a scanner's own timeout from being cancelled because a
sibling scanner already decided the verdict.
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
