Failing test: with the only processing slot held, a request for a new
width of a cached image waits for the slot while the cached file is
rewritten; the answer must come from the rewritten file, so the request
read none of the source before it had a slot. Also a test that a fetch
whose request context ends while it waits for a connection shared by all
hosts gives its host's slot back; that one passes already.
Model: opus-5-5
max_concurrent_processing (default: the number of CPUs Go uses) bounds
the images processed at once, and upstream_connections (default 64) the
fetches from all upstream hosts together, beside the per-host limit. A
request that finds either full waits up to 10 seconds, then gets 503
"server busy, try again later". The processor holds its slot from before
it reads the input until it returns, and takes a free slot even after the
request context has ended; a fetch holds its connection until the
response body is closed, after its image is processed. libvips now starts
with one worker thread per image and no operation cache. Both settings
have PIXA_ variables and are in README.md and config.example.yml.
Model: opus-5-5
Failing tests for two limits that do not exist yet. Config:
max_concurrent_processing and upstream_connections, their defaults, and
valid and invalid values from the file and the environment. Image
processor: never more images at once than its limit, waiting and then
failing with ErrTooManyImages when no slot frees, and freeing its slot on
every error. Fetcher: connections to all hosts counted together, apart
from the per-host limit, and freed on errors. Both image routes answer
503 when either wait gives up. TestEnvironmentSetsEveryKey sets the two
new variables, as it compares the whole config. The tests do not compile
until the limits exist.
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)
internal/httpfetcher had only helper-level tests. This adds tests of the full Fetch path, with no non-test code changed: a redirect to a private address is refused and never dialed while public redirects and a two-hop chain still work; the per-host semaphore is released on error, after a full read and after a partial read; an oversized body yields ErrResponseTooLarge; non-2xx and disallowed content types are rejected; the dialer blocks private, link-local and loopback targets.
What a reader would trip over: the upstream host in the tests is the TEST-NET-1 literal 192.0.2.10, which the private-IP check treats as public; a recording dialer routes it to the local test server and records every dial.
Disclosure: DNS rebinding is not simulated end to end (it would mean changing the global resolver under parallel race tests); the dial-time re-resolution is tested directly instead.
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
