Every response carries X-Request-Id, the upstream fetch sends it, and
the "upstream fetched", "image converted" and "image served" lines log
it as request_id. pixa's own RequestID middleware keeps a request's own
ID only when it is at most 64 letters, digits, '-', '_' or '.', and
otherwise makes a random one with crypto/rand, so nothing a client
chooses freely and nothing about the host reaches upstream. /v1/e/ now
sets ETag, answers a matching If-None-Match with 304 and is routed for
HEAD, through notModified, which both image handlers call. No Vary is
added: go-chi/cors already sends Vary: Origin.
Model: opus-5-5
Each upstream host's semaphore now counts the fetches holding or waiting
for one of its slots, and is removed from hostSems when the last of them
gives its slot back or stops waiting, so a long-running pixad no longer
keeps one semaphore per host it ever fetched from.
VariantStorage.Delete removes the variant's .meta file too, a missing one
not being an error; DeleteWithMeta, which eviction called for that, is
gone.
Model: opus-5-5
Nothing bounded total in-flight work, so a burst of cache misses across
hosts could exhaust memory. Two settings now do: max_concurrent_processing
(default the CPUs Go uses) and upstream_connections (default 64, beside
the per-host limit). A request that finds either full waits up to 10
seconds, then gets 503; a slot is released on every path. No request
holds source bytes while it waits: a cached source is read only after
the processing slot is taken, and a fetched one only while it holds its
upstream connection. libvips runs one worker thread per image with its
operation cache off. Both waits count toward downstream_timeout, as the
README says.
Model: opus-5-5
Adds the blocked_networks config key: a list of CIDRs, parsed with net/netip, that is added to the built-in list of address ranges the fetcher refuses to contact and can never remove an entry from it. An invalid CIDR aborts startup naming the key and the value.
The built-in list gains CGNAT 100.64.0.0/10, IETF protocol assignments 192.0.0.0/24, benchmark 198.18.0.0/15 and NAT64 64:ff9b::/96. Resolved addresses are unmapped before matching, so IPv4-mapped IPv6 forms are caught too. Enforcement stays in the dial-time re-resolution, which is what closes the DNS rebinding window.
What a reader would trip over: 192.0.0.0/24 is now blocked but TEST-NET-1 (192.0.2.0/24), which the Fetch tests use as a public upstream, is a different range and stays dialable. The package-level dialer enforces the built-in ranges only; operator entries are applied by the fetcher.
Disclosure: one nolint:gochecknoglobals on the immutable built-in prefix list.
Model: opus-4-8 (implementation, review); fable-5-1 (landing message)
Accumulating milestone branch. One squashed commit per closed issue; `next` is kept green and mergeable to `main` at any time without notice.
Landed so far:
- `chore: update golangci-lint to v2.12.2 with canonical config` (#54) — canonical v2-schema `.golangci.yml`, pins bumped in `Dockerfile` and `script/bootstrap`, tree at `0 issues.`. Three behaviour deltas are recorded in that PR's body: `Cache.StoreVariant` takes a context, `MetadataStorage.Store` no longer leaks temp files on failure, and the `signing_key` too-short error text gained a `value too short:` prefix.
Sequencing for the milestone is tracked in #103.
Reviewed-on: #105
Co-authored-by: clawbot <clawbot@noreply.example.org>
Extracts the HTTP fetcher concern out of `internal/imgcache/` into its own `internal/httpfetcher/` package, per the plan in [issue #39](#39).
This is one of four planned extractions; only the fetcher is moved here so the diff stays reviewable. The remaining three (signature, magic, urlparser) will land in separate PRs.
## What moved
From `internal/imgcache/fetcher.go` and `internal/imgcache/mock_fetcher.go` into `internal/httpfetcher/`:
- `HTTPFetcher` type, its `New` constructor, and `Config` (formerly `FetcherConfig`) with `DefaultConfig`
- SSRF-safe dialer, `validateURL`, `isPrivateIP`, `isLocalhost`, `extractHost`
- Per-host connection semaphore (rate limiting) and `limitedReader`
- Content-type validation (`isAllowedContentType`, `detectContentTypeFromPath`)
- All related error values (`ErrSSRFBlocked`, `ErrUpstreamError`, `ErrUpstreamTimeout`, `ErrPayloadTooLarge`, `ErrDisallowedContentType`)
- All related constants (`DefaultFetchTimeout`, `DefaultMaxPayloadBytes`, `DefaultMaxConnectionsPerHost`, etc.)
- The `Fetcher` interface and `FetchResult` type (moved here to keep the import edge one-way: `imgcache` depends on `httpfetcher`, never the reverse)
- `MockFetcher` test helper
## Renames (no stuttering)
- `NewHTTPFetcher` → `httpfetcher.New`
- `FetcherConfig` → `httpfetcher.Config`
- `DefaultFetcherConfig` → `httpfetcher.DefaultConfig`
- `NewMockFetcher` → `httpfetcher.NewMock`
The `ServiceConfig.FetcherConfig` field name is retained — it describes what kind of config the field holds (not a stutter).
## Behavior
Pure refactor. No behavior changes. All existing tests pass; unit tests for the new package are included.
`docker build .` passes (fmt-check, lint, test, build).
refs #39
Co-authored-by: clawbot <clawbot@eeqj.de>
Co-authored-by: Jeffrey Paul <sneak@noreply.example.org>
Reviewed-on: #43
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
clawbot
