alternative deviantart frontend, no javascript. go. http://git.krz.sh/krz/skunky-art.git/atom?h=main 2026-08-02T13:30:01+00:00 2026-08-02T13:30:01+00:00 Christian Cleberg hello@cleberg.net 2026-08-02T06:51:22+00:00 urn:sha1:4178e3893f310425e76f6d4515af9e7d0ea36a0a 2026-07-15T16:41:18+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T16:41:18+00:00 urn:sha1:184ce2c6dcdd047d6888fd243b9189c797f58d38 * fix: make memcache concurrency-safe and stamp the version at link time memcache was a crash waiting for traffic. Readers touched tempFS without holding mx, while a per-entry goroutine deleted from it under the lock: a concurrent map read and map write, which the runtime treats as a fatal error that recover cannot catch. The option ships in config.example.json and was the one cache key SETUP.md never documented, so it read like a free win to enable. Put every map and field access behind the mutex, and age the whole map from one janitor instead of a goroutine per cached file, each of which looped forever holding its entry alive. mx is now a plain Mutex: every operation here mutates something, and the old code took an RLock to write. Document the option, and cover it with tests that run the readers, writers and janitor concurrently. Split the disk/origin fetch out of DownloadAndSendMedia while there, so the error path returns instead of falling through to write an empty body after the error page. Release.Version was hardcoded to 1.3.2, so images tagged v1.3.6 reported 1.3.2 from --help and /api/instance, and --help linked to the wrong release. Take it from a main.version string the release workflow links in from the git tag. * fix: reject forged subdomains in the media proxy DownloadAndSendMedia built its upstream URL by concatenation, pasting the subdomain segment of the request path straight into the host position. That segment reaches the handler already percent-decoded, so it can carry "@", "#", "?" and "/" — the characters that end a host. A request for /media/file/x@127.0.0.1:8080%2F/f/x.jpg built a URL whose host parsed as 127.0.0.1:8080, with images-wixmp-x demoted to userinfo, letting any caller aim the instance's fetcher at any address it could reach, including services behind the firewall. Validate the label against ^[a-zA-Z0-9-]+$ and refuse anything else with a 400. Rejecting rather than escaping is what closes this: the label is the host, and url.URL passes a host through verbatim, so building the URL structurally is not sufficient on its own. DeviantArt's own media URLs use a hex-and-dash label, and ParseMedia already splits on the first dot, so a legitimate label cannot contain one. Build the URL from url.URL fields as well, which escapes the path, and encode the token argument, which reached the request unescaped. Reported by CodeQL as go/request-forgery (CWE-918). 2026-07-15T16:13:25+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T16:13:25+00:00 urn:sha1:8e8c03891a17798067a8da0a034725bf44ece8d0 An unwritable cache directory degraded silently: media still served, because the download succeeds before the cache write is attempted, so the only symptom was one "permission denied" line per request and a cache that never filled. Every request re-fetched from the CDN. Probe the directory at startup and exit with the uid and the chown that fixes it. The container image runs as uid 10000, which is the usual cause with a bind-mounted cache, so say so in the message and in both compose examples. 2026-07-15T08:17:09+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T08:17:09+00:00 urn:sha1:83d9cd0b7a3e0ec6beb5c889102211567a6db03f Two independent faults made every image fail while pages still rendered. config.example.json shipped download-proxy=http://127.0.0.1:8080. Only media fetches go through that proxy — pages reach DeviantArt via devianter on the default transport — so when nothing listens there, images 502 and the rest of the page looks fine. In a scratch container 127.0.0.1 is the container itself, so the default could never work under Docker. Unset it and document that it must stay empty unless an operator really runs a proxy. Host was a package global reassigned by every request, so a concurrent request could overwrite it mid-render and emit URLs on another origin's host and port. The instance's own default-src 'self' CSP then blocked those images. Thread the request's host through skunkyart instead, and take it as an explicit argument in URLBuilder, ParseMedia, ParseDescription, BuildUserPlate and ConvertDeviantArtURLToSkunkyArt. Feeds keep their absolute URLs. Also start RefreshInstances after ExecuteConfig rather than before it: the goroutine read CFG while json.Unmarshal was writing it (a race the detector flags), and its fetch escaped both the throttle and the configured User-Agent. Verified: 300 concurrent requests with distinct Host headers now round-trip their own host (was 1 leak per 300), go test -race is clean, and cache+proxy both enabled serves 200 image/jpeg cold and from cache. 2026-07-15T07:34:41+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T07:34:41+00:00 urn:sha1:bc9c79be7824252f385b9d052595ed8d7460f43f The copyright on /about and in the CLI help credited only lost+skunk and linked to their matrix account. Credit this fork alongside the original, as the X11 license requires retaining the upstream notice, and point the attribution at the upstream repo rather than the stale matrix link. Replace the upstream matrix room link with this fork's issue tracker. 2026-07-15T07:25:20+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T07:25:20+00:00 urn:sha1:d6789522d3dd076f7c98dafa3e7d42df09252093 The remaining golangci-lint findings. These land together because the Url -> URL rename spans util.go, parsers.go and wrapper.go, and splitting it would leave an intermediate commit that does not compile. Download() carried the most serious bug here: try() only prints an error, it does not return, so a failed request fell through to resp.Body.Close() on a nil resp and panicked. Every failure path now returns the zero Downloaded, and callers check Status. ReturnHTTPError guards against the resulting status 0, which would otherwise panic WriteHeader. Requests carry a context with a timeout (noctx), and a download-proxy now routes through ProxiedTransport so it keeps the DA throttle and timeouts. Also: - doc comments on all 48 exported symbols (revive's exported rule, with checkPrivateReceivers, since most of app is exported methods on the unexported skunkyart type), plus package docs in new doc.go files so both the embed and non-embed builds are covered. - ST1003 naming: UrlBuilder -> URLBuilder, id_search -> idSearch, cache_config -> cacheConfig, TXT_RAW -> TxtRaw, mediaUrl -> mediaURL. - explicit json tags on structs that are unmarshaled (musttag); the hyphenated keys already had tags, the rest relied on case-insensitive fallback. Behaviour is unchanged. - modernization: range-over-int, WaitGroup.Go, stale +build lines, interface{} -> any, strings.Builder over string concatenation in a loop. 2026-07-15T07:24:58+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T07:24:58+00:00 urn:sha1:7eb5e5e2230b6fb5b1bed6f0eaa03279aa61555b Correctness and security findings surfaced by golangci-lint, plus two latent panics found alongside them. - router: http.ListenAndServe has no timeouts at all (gosec G114), so a slow client could hold a connection and its handler open indefinitely. Replace it with an explicit http.Server carrying read/write/idle timeouts. - httpclient: InstallDAThrottle asserted http.DefaultTransport was a *http.Transport and would panic outright if anything had already wrapped it -- which is precisely what that function does. Check the assertion and fall back to a fresh transport. Expose ProxiedTransport so a configured download-proxy can inherit the same throttle and timeouts instead of silently bypassing them. - cache: the Sys() assertion to *syscall.Stat_t is only valid on unix and would panic elsewhere; skip rotation instead. Indexing Headers["Content-Type"][0] panics when the header is absent; use Headers.Get. Cache files are written 0600 rather than 0700, as they are never executed. - cli, api: check error returns, and exit rather than nil-dereference a file handle that failed to open. SHA-1 and math/rand keep //nolint:gosec with reasons: they are cache-key hashes and random-artwork picks, not security primitives. 2026-07-15T07:23:59+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T07:23:59+00:00 urn:sha1:40d405f318a109aad5e7de7ad71fedcc04bb0e86 max-size is documented in SETUP.md as megabytes, but the conversion was `*= 1024 ^ 2`. In Go `^` is XOR, not exponentiation, so this multiplied by 1026 rather than 1048576 -- a configured max-size of 200 produced a ~205 KB cap instead of 200 MB, wiping the cache almost immediately. This changes runtime behaviour: the cache will now grow to the size the config actually asks for. 2026-07-15T06:58:41+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T06:54:26+00:00 urn:sha1:b1ad14553277d9d72a5e4b4462a52a2e2d0fdbb1 2026-07-15T01:28:02+00:00 Christian Cleberg hello@cleberg.net 2026-07-15T01:28:02+00:00 urn:sha1:0aff13949a8e9e120a585f00627ef6959f8e0635 Upstream references still pointed at git.macaw.me, which is unmaintained and whose instances.json is a dead link. Repoint them at this repo: - RefreshInstances now fetches instances.json from raw.githubusercontent - source/version links in index.htm, about.htm, and CLI help use the GitHub releases tag URL - SETUP.md/SETUP-RU.md language switch links were Gitea-absolute paths that 404 on GitHub; make them relative - --add-instance message says 'main' branch, matching this repo The fork attribution in README.md is left as-is: it credits upstream rather than pointing at the source.