Add cache_max_bytes to config.example.yml and the README key settings
list. TODO.md: move cache size management and eviction to Completed
Steps, promote P1 blocked networks configuration into Next Step, and
note in Status that the unbounded disk growth DoS vector is closed.
closes#52
Implements startup configuration validation per the plan on #52. Two commits, TDD: the first commit adds the enforcement tests (red — six test functions fail against the lenient behavior) plus a mechanical extraction of `newFromSmartConfig` from `config.New` so construction is testable without fx; the second commit makes them green and carries the `TODO.md` bookkeeping.
## Behavior
- **No silent fallbacks**: a config value that is SET but unparseable or invalid aborts startup with an error naming the key and value. Defaults apply only to OMITTED keys. The old `getString`/`getInt`/`getBool` helpers swallowed every conversion error and returned the default; they are now strict. Fractional ports are rejected, not truncated (smartconfig's `GetInt` would have turned `8080.5` into `8080`).
- **Unknown keys abort**: unknown top-level keys and unknown `metrics` subkeys are fatal, each named in the error (`unknown config keys: whitelist_hosts`). The `env` section stays permitted because smartconfig consumes it for environment injection.
- **Malformed config file aborts**: a config file that exists at a standard location but fails to parse was previously logged as a warning and skipped (the server would start on defaults); it is now fatal.
- **Range/sanity checks**: `port` in 1-65535; `upstream_connections_per_host` at least 1; `signing_key` required, at least 32 characters (keyless mode was never implemented; the stale "leave empty" comment in `config.example.yml` is corrected); `allowlist_hosts` entries must be bare hostnames (leading-dot suffix patterns still allowed; schemes, paths, whitespace, non-string and empty entries rejected); `state_dir` non-empty and verified creatable+writable with a probe file before the listener binds; `sentry_dsn` must be a URL with scheme and host when set; `metrics.username`/`metrics.password` must be set together.
## Verification
- `make check` green on the branch head (all tests, golangci-lint 0 issues, fmt-check clean).
- End-to-end: `./bin/pixad` with `port: banana` exits 1 printing `config key "port": value "banana" is not an integer`; with `whitelist_hosts:` it exits 1 printing `unknown config keys: whitelist_hosts`.
## Notes for review
- `getStringSlice` keeps its lenient signature because the existing tests in `config_test.go` exercise it and modifying existing tests requires explicit approval. Strictness for `allowlist_hosts` is instead enforced up front on the raw value by `validateAllowlistHostsValue`, so nothing is silently skipped; extraction then reuses the existing parser. If you prefer the helper folded into a single strict function, that requires retargeting those three tests — happy to do that as a follow-up with approval.
- `TODO.md` here is edited against current `main`; PR #50 (merge-ready) edits adjacent lines, so whichever merges second will need a trivial rebase of `TODO.md` only.
- The README Configuration section lists keys that have never existed in the code (`access_control_allow_origin`, `upstream_fetch_timeout`, `upstream_max_response_size`, `downstream_timeout`). Under this change a config using them now fails fast instead of silently doing nothing — that is the intended behavior. Implementing them is already tracked as the P2 "add all configuration options from README" item in `TODO.md`.
Co-authored-by: sneak <sneak@sneak.berlin>
Reviewed-on: #53
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
Extracts HMAC-SHA256 request signing out of `internal/imgcache/` into its own `internal/signature/` package, per the plan in [issue #39](#39).
This is one of the remaining "easily separable" extractions (`imageprocessor`, `allowlist`, `magic`, and `httpfetcher` already landed). Only the signer is moved here so the diff stays reviewable.
## What moved
From `internal/imgcache/signature.go` and its tests into `internal/signature/`:
- `Signer` type, its `New` constructor, `Sign`, `Verify`, `GenerateSignedURL`
- `ParseParams` (query-string signature/expiration parsing)
- Signature error sentinels
## One-way import edge
To keep the import edge one-way (`imgcache` depends on `signature`, never the reverse), the package defines a standalone `Request` type carrying just the fields the signature covers, instead of importing `imgcache.ImageRequest`. `imgcache` projects its `ImageRequest` onto `signature.Request` via a small unexported `signatureRequest` helper. This mirrors how the `magic` extraction defined its own `ImageFormat` type.
## Renames (no stuttering)
- `NewSigner` -> `signature.New`
- `ParseSignatureParams` -> `signature.ParseParams`
- `ErrSignatureRequired`/`Invalid`/`Expired` -> `signature.ErrRequired`/`Invalid`/`Expired`
The `ErrRequired` message is updated from "non-whitelisted host" to "non-allowlisted host" for inclusive terminology, consistent with the `allowlist` rename.
## Rework (post-review)
Three commits added after review feedback:
- `d69019b` — golden known-answer test pinning the exact HMAC signatures and signed URL paths for three fixed vectors (resized, resized+query, orig size), cross-validated against an independent HMAC implementation. Any change to the signed byte format now fails loudly.
- `43b9f1c` — whitelist→allowlist rename completed across `internal/imgcache` and `internal/handlers` (`ServiceConfig.Allowlist`, `Allowlist` interface, `IsAllowlisted`, test helpers and test names).
- `3dc1999` — one-pass config surface rename, no back-compat alias: YAML key `whitelist_hosts` → `allowlist_hosts`, `Config.WhitelistHosts` → `Config.AllowlistHosts`, `config.example.yml`, `scripts/manual-test.sh`, and `README.md` (which also documented a nonexistent `source_host_whitelist` key — now fixed to the real one).
## Behavior
Pure refactor apart from the config key rename above. The bytes fed to the HMAC are unchanged (`host:path:query:width:height:format:expiration`), so previously issued signatures remain valid — now enforced by the golden test. All existing tests move with the package. `script/cibuild` passes at head `3dc1999` (fmt-check, lint, test, build).
refs #39
Co-authored-by: sneak <sneak@sneak.berlin>
Co-authored-by: Jeffrey Paul <sneak@noreply.example.org>
Reviewed-on: #46
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
- Add config validation: signing_key required, minimum 32 characters
- Server now fails to start without valid signing_key (no more runtime errors)
- Add config.example.yml with default whitelist hosts
- Copy config to /etc/pixa/config.yml in Docker image
- Update entrypoint to use --config /etc/pixa/config.yml
- Add config.dev.yml for local Docker development
- Mount dev config in make devserver
