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
