BountyBoard/DECISIONS.md

Decisions

Spec-silent choices, recorded as required by the build instructions.

Phase 1

• Go toolchain 1.26.4 (latest stable; spec requires ≥ 1.22). Installed at /usr/local/go.
• Module name bountyboard — no remote repository exists; a single-word module keeps import paths short (bountyboard/internal/...).
• Package in internal/http is named httpx to avoid clashing with stdlib net/http inside its own files. The directory stays internal/http per spec §14; importers alias it (httpx "bountyboard/internal/http").
• /readyz uses a pluggable checker registry (AddReadinessCheck): required checks (Mongo, Phase 2) gate readiness with 503; optional checks (atomizer / work performer, Phase 11) are reported as degraded but stay 200, matching §6's "non-fatal, reported".
• Runtime image is alpine:3.21, not distroless — busybox wget enables the compose healthcheck without adding tooling, and ca-certificates is needed for outbound HTTPS to Jira/ADO/YouTrack. Non-root user.
• Config validation is strict and fail-fast: CREDENTIALS_ENC_KEY is mandatory at startup (base64, exactly 32 bytes) and SESSION_SECRET must be ≥ 16 chars, even before the features using them land — a misconfigured deployment should die at boot, not at first use. All validation errors are reported together via errors.Join.
• Trusted-proxy resolution walks X-Forwarded-For right-to-left, skipping addresses inside TRUSTED_PROXY_CIDRS; the first untrusted address is the client. A malformed entry stops the walk (everything left of it is attacker-controllable). If the whole chain is trusted, the leftmost entry is used. Headers are ignored entirely when the direct peer is untrusted.
• ULID: canonical 48-bit ms timestamp + 80-bit crypto randomness, no intra-millisecond monotonicity (spec only needs sortability at ms resolution; randomness makes collisions negligible).
• .env loader semantics: real environment variables win over .env values; unquoted values support trailing # comment; missing .env file is not an error (containers receive env via compose env_file).
• Makefile seed/backup/restore are failing stubs until Phase 12 so the targets exist but cannot be mistaken for working.

Phase 2

• Integration tests reach Mongo via docker-compose.test.yml, an explicit test-only overlay publishing Mongo on 127.0.0.1:27017. The normal compose file still never publishes Mongo (§12); the spec's integration-test requirement (§2.1) needs host access, and a loopback-only opt-in overlay is the smallest hole. Each run uses a bountyboard_test_<ulid> database and drops it on cleanup.
• UpdateVersioned rejects updates that touch version and merges updatedAt/$inc version into the caller's operators; it distinguishes ErrNotFound from ErrVersionConflict with a follow-up existence check.
• File MIME type = sniffed (http.DetectContentType) unless inconclusive (application/octet-stream), in which case the client-declared type is kept. A confident sniff overrides a lying declaration.
• sha256 of uploads is recorded post-upload via an update on fs.files metadata (GridFS metadata must be supplied before streaming; the hash is only known after).
• Signed file tokens are base64url(exp || hmac-sha256(fileID|exp)) with a key derived as sha256("bountyboard/file-url/v1" + SESSION_SECRET) so file tokens can never collide with other uses of the session secret.

Phase 3

• OIDC linking requires email_verified=true. An unverified IdP email matching an existing local account is rejected (oidc_email_unverified) instead of linking or creating a duplicate — linking on unverified email would allow account takeover via a rogue IdP account.
• OIDC provider discovery is lazy (first login attempt, retried on failure) so an unreachable IdP cannot block app startup.
• CSRF protection applies to authenticated mutations only; login and register are pre-session and protected by rate limiting + SameSite=Lax. The CSRF cookie is intentionally JS-readable (double-submit pattern).
• Password change revokes all other sessions of the user (recovery semantics) but keeps the current one. SetPassword is deliberately not version-checked: a password change must never lose an optimistic-locking race against a profile edit.
• Forced password change (mustChange) is enforced in requireAuth via a path allowlist (me, logout, logout-all, change-password).
• Sessions slide at most once per hour (refreshedAt watermark) instead of updating expiry on every request.
• Login rate-limit key is clientIP|email (and register|clientIP for registration), using the trusted-proxy-resolved IP.
• Mongo runs with --wiredTigerCacheSizeGB 0.5 in compose — the target host has 4 GB RAM; default cache (≈50% of RAM) caused a restart under the integration-test load.