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
The README told operators to set trusted_proxies to the proxy's own
address. A proxy on the Docker host that connects over 127.0.0.1 reaches
pixa from the Docker network's gateway, so that advice made pixa count
every user as one client for the login limit. The login-limit paragraph,
the trusted_proxies entry and config.example.yml now say to use the
address pixa sees for requests through the proxy, that a proxy connecting
through another host address is seen with that address, and how to read
it from the request log.
The signature section now says sig is base64url with the = padding
kept, since pixa compares it exactly, and shows the example's sig for a
stated key, computed with pixa's signer.
Model: opus-5-5
Cache.Stats read request_cache and output_content, which nothing
writes, so TotalItems and TotalSizeBytes were always 0. They now count
source_content plus variant_content and use UsageBytes; a disabled disk
cache reports 0 for both. The upstream fetch count and bytes and the
transform count never moved: Get now passes the bytes it fetched
(including those read before a failed body read) and counts each
successful transcode. Hits, misses and these counters are written with
context.WithoutCancel, so a client disconnect or the request timeout no
longer loses them. The unused tables stay; metaCache is #70.
Model: opus-5-5
adduser took the first free uid, 1000, and the entrypoint gives a
bind-mounted /var/lib/pixa to pixad, so on the host a person's login
account ended up owning pixa's database and cache. The image now creates
the pixad group with gid 65532 and the pixad user with uid 65532, which
host login and system accounts do not use. The first-run step of
"Running under upaas" in README.md names the uid and gid.
Model: opus-5-5
Both image routes sent Cache-Control: public, max-age=31536000,
immutable unconditionally, so a browser or proxy could keep serving an
image for a year after its signed or encrypted URL had expired. max-age
is now the whole seconds left until the URL expires, never negative and
at most one year; a URL with no expiry keeps one year. The 304 answer
uses the same value. An encrypted URL's expiry now reaches
ImageRequest.Expires through ToImageRequest. immutable stays: freshness
now ends no later than the URL's expiry. README.md documents the header.
Model: opus-5-5
Every output is exported with govips' StripMetadata, so it carries no
EXIF (GPS, serial numbers, embedded thumbnails), XMP, IPTC or ICC
profile, the orig format included: it is always re-encoded, and pixa
never serves the source bytes. The image is turned upright with
AutoRotate right after decoding, so dropping the orientation tag does
not leave it rotated, and a requested size applies to the upright
image. An image with an ICC profile is converted to sRGB before export.
No setting turns this off. README.md documents it.
Model: opus-5-5
POST / had no limit, so the signing key could be guessed at no cost. It
is now limited to 5 attempts per minute per client by a new RateLimit
middleware on github.com/go-chi/httprate; an attempt over the limit gets
429 with Retry-After. It counts by the address the ClientIP middleware
resolved through trusted_proxies (an IPv4-mapped address as its IPv4
address, IPv6 by its /64) and runs after the body-size and CSRF checks,
so every attempt that reaches the key comparison is counted. README says
that with the default trusted_proxies a client with a private address
can choose its counted address, and how to close that.
Model: opus-5-5
An exp that was not a whole number, or empty, was ignored, so a URL for
a host that needs a signature got 401 as if it had no exp. It is now a
400 naming exp and the value, on every host; only an exp missing from
the URL is unchanged.
A failed variant .meta write, source metadata JSON write, Stats count
query, stats counter update, negative cache write or expired negative
cache delete was discarded without a trace. Each is now logged at warn
with the path or key and the error, and stays non-fatal, with tests for
those that can be made to fail. VariantStorage takes the cache's logger.
Model: opus-5-5
A fit in the URL with an empty value (fit=) was treated as missing, so
it was served as cover and verified against a signature made for cover.
It is now a 400 naming fit, the same rule the route applies to an empty
q. It is checked before the existing fit-mode check, which takes an
empty fit as missing; any other value still goes through that check
unchanged. Only a fit missing from the URL is cover.
Model: opus-5-5
A q that was not a number or was outside 1-100 was dropped and 85 used,
so q=500 was served and verified against a signature made for 85. It is
now a 400 naming q and the value, read with the generator's quality
check; only a q missing from the URL is 85.
The route also refuses with 400 a query string that cannot be decoded
(r.URL.Query() drops such a pair, so q=80% arrived as no q) and any
parameter given more than once, which was read from its first value only
(q=80&q=500 was served at 80).
Model: opus-5-5
A variable whose name starts with PIXA_ but is neither a setting's
variable, from the list pairing each config key with its variable, nor
PIXA_CONFIG_PATH now aborts startup naming it, as an unknown config key
does. PIXA_PORT is named with a pointer to PORT. The check runs after
the config file loads, so the variables the file's env section sets are
checked too. README.md says so under Configuration.
Model: opus-5-5
The old comment said the flag stops the image's 30-second interval from
delaying the first probe past the wait. From Docker 25 on, the first
probe runs 5 seconds after start either way; the flag makes probes
after the 10-second start period come every second instead of every
30. Only the comment changes; TODO.md is left alone because the issue
limits the change to this script.
Model: opus-5-5
The encrypted /v1/e/ route used the decrypted payload unchecked, so a
token could request an over-limit size or an unknown fit mode; the
generator turned unparseable numbers into 0.
imgcache.ValidateDimension alone holds the MaxDimension bound and is
used by the path parser, by the new ValidateImageRequest (which adds
ValidateFitMode) and by the generator. Both image routes call
ValidateImageRequest, so each answers 400. The generator answers 400
naming the field for a width or height that is not a number or fails
that check, a quality that is not a number from 1 to 100, a ttl that is
not a number from 0 to the largest the expiry calculation can hold, or
an unknown fit. Empty quality is 85; empty ttl never expires. The
form's size inputs stop at 8192.
Model: opus-4-8 (implementation); opus-5-5 (rework)
upaas bind-mounts an existing host directory and sets no container
user, so a directory made with mkdir as root left pixad unable to
write /var/lib/pixa, and the container exited at startup.
The image now starts as root: deploy/docker-entrypoint.sh gives
/var/lib/pixa to pixad when pixad does not own it, then runs the
server as pixad through su-exec (alpine's package), so the server
never runs as root. README.md gains a "Running under upaas" section:
port, volume, environment variables, health check, first-run step.
Model: opus-5-5
make lint calls script/lint, the only way golangci-lint is run. Inside a
container it runs the linter; anywhere else it builds Dockerfile.lint,
whose last step runs script/lint again. Both Dockerfiles set
container=docker to mark the container, since /.dockerenv is missing in
build steps and present on hosts that are themselves containers. The
Dockerfile lint stage runs make lint.
A new CACHEBUST build-arg on every run keeps the lint step from being
served from cache; a tmpfs mount keeps Go's and golangci-lint's caches
out of that step's layer, so runs do not pile up build cache.
script/bootstrap and the nix-shell package lists no longer carry
golangci-lint. golangci-lint config verify is not run: it fetches its
schema over an unpinned live HTTPS call.
Model: opus-4-8 (implementation); opus-5-5 (rework)
Each config key can now be set by PIXA_ plus the key in upper case
("." written as "_"), and the port by PORT. A present variable, even
an empty one, is read before the config file through the existing
typed getters, so every existing check covers it; errors name the key
and the variable, never the signing key or metrics password. A
variable named in the file's env: section overrides both. An empty
string for blocked_networks or trusted_proxies is now an empty list.
The image no longer bakes in config.docker.yml or passes --config; its
HEALTHCHECK probes ${PORT:-8080}. The config file is looked for under
/etc/pixa rather than /etc/pixad. Also covers #99.
Model: opus-5-5
The signed data is now
host:path:query:width:height:format:expiration:quality:fit. The route
turns a missing q into 85 and a missing fit into cover before checking
the signature, so those are the values signed for a URL without them;
imgcache fills both from the parsed request.
imgcache.Service.GenerateSignedURL now writes q and fit into the URL
next to sig and exp, first setting an unset quality or fit to 85 or
cover, so a generated URL verifies for the values it signed.
The known-answer vectors in golden_test.go, including one for quality
40 and fit contain, and the README signature section describe the new
format.
Model: opus-4-8 (implementation); opus-5-5 (rework)
The runtime stage declares a HEALTHCHECK that probes
/.well-known/healthcheck.json with busybox wget. script/docker-smoke
(make docker-smoke) builds the image with script/docker, starts it with
a random PIXA_SIGNING_KEY, and passes only once Docker reports the
container healthy within 30 seconds; the container is removed on exit
and its log printed on failure. The Gitea workflow runs it after
script/cibuild; it is not part of make check.
It waits on Docker's health status instead of polling a published host
port because the Gitea job runs in its own container on its own
network, where such a port is not reachable at localhost.
Model: opus-5-5
RFC1918 ranges are the default trusted proxy set on an omitted key; an explicit list replaces the default; an explicit empty list trusts no one; unparseable values abort startup; forwarded headers honored only from trusted peers. Independent review passed: #127 (comment)
model: claude-opus-4-8 (implementation and review); merged by claude-fable-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)
The Docker image now ships config.docker.yml, which sets only signing_key (read from the PIXA_SIGNING_KEY environment variable), state_dir and port. The placeholder key and the five-host allowlist from config.example.yml are no longer in the image; anything else is configured by mounting a file over /etc/pixa/config.yml. A container started without PIXA_SIGNING_KEY exits naming it.
Startup now refuses the exact placeholder signing_key from config.example.yml. It is 45 characters long and used to pass the length check, so a deployment could sign URLs with a key that is public in this repository. README Getting Started is corrected to match.
What a reader would trip over: the unset-variable error comes from config interpolation, not from validate(); the signing key checks moved into validateSigningKey to stay under the complexity limit.
Disclosure: TODO.md is not updated by this change.
Model: opus-4-8 (implementation, review); fable-5-1 (landing message)
The http.Server now sets ReadHeaderTimeout (10s), which bounds the slow header dribble that ReadTimeout alone does not, and IdleTimeout (120s), which bounds keep-alive reuse. Server construction moved into a small helper so a test can assert the timeouts without binding a listener.
POST / and POST /generate bodies are capped at 1 MiB and an oversized body returns 413.
What a reader would trip over: the CSRF library reads its token from the form and swallows a parse error, so a cap applied only inside it would surface as 403. The body limit therefore parses the form under the cap before the CSRF check; the parsed form is reused afterwards. A test covers an oversized body that carries a valid token.
Judgement call: WriteTimeout stays at 60s; it also bounds how long a large image may take to send over a slow link.
Model: opus-4-8 (implementation, review); fable-5-1 (landing message)
SecurityHeaders() now also sets Strict-Transport-Security (one year, includeSubDomains), a Content-Security-Policy (default-src self, frame-ancestors none) and a Permissions-Policy denying the browser features pixa does not use. X-Frame-Options stays as the legacy fallback.
What a reader would trip over: HSTS is sent on every response even though pixa listens on plain HTTP behind a TLS-terminating proxy; browsers ignore the header over plaintext, and this avoids trusting a forwarded-proto header. The clipboard feature is left unlisted so the copy button on the generator page keeps working.
Disclosure: script-src and style-src carry unsafe-inline because the generator template has inline onclick handlers and the bundled Tailwind script injects a style element at runtime; removing it needs template changes and is tracked separately.
Model: opus-4-8 (implementation, review); fable-5-1 (landing message)
The Workflow section of TODO.md still told contributors to branch from main and merge there. It now describes the current model: one branch per issue cut from next, a PR based on next, an independent reviewer, a squash-merge into next by the manager, and only the owner merging next into main through the milestone PR. The Status paragraph no longer claims work is green on main.
Disclosure: only the wrong lines are touched; reflowing the whole file is left to #100.
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)
script/test now runs the suite quietly first (with -race and -cover, 30s timeout) and re-runs it with -v only when that run fails, then exits non-zero. This is the pattern REPO_POLICIES.md mandates; before, every green run printed full per-test output.
What a reader would trip over: the whole compound command is passed as one string to run_with_cgo_deps, so it behaves the same on the host path and under the nix-shell fallback. -cover is on the first run only; the verbose rerun exists for diagnostics.
Disclosure: no test was written for the wrapper script itself; the failure path was exercised by hand by author and reviewer.
Disclosure: the nix-shell fallback is kept; moving tests into Docker belongs to #101 and #104.
Model: opus-4-8 (implementation, review); fable-5-1 (landing message)
Adds CSRF protection to the two cookie-authenticated form posts, POST / (login) and POST /generate, using github.com/gorilla/csrf, the recorded default for this job.
The token key is derived from signing_key with its own HKDF salt, so it needs no new config and survives restarts. The token cookie is separate from the session cookie, which also covers login CSRF, where no session exists yet. Both templates carry the hidden token field.
What a reader would trip over: outside debug mode the library enforces its https Referer origin check, so the TLS-terminating proxy must preserve the Host and Referer headers from the browser or form posts are rejected.
Disclosure: one nolint:gosec on a test constant holding the library field name (G101 false positive).
Model: opus-4-8 (implementation, review); fable-5-1 (landing message)
clawbot