AUDIT-WP-0005-T01, built and verified against PostgreSQL 16 locally in
Docker; the Railiance cluster was not needed.
tests/test_backend_conformance.py is one suite run against every backend, so
"the Postgres backend is done" means it satisfies the same contract SQLite
already does rather than having its own green tests. It skips cleanly with no
server reachable; make pg-test-up and make test-pg run it. Suite 50 -> 71.
RetentionPolicy declares immutable=True and earns it: migration 0002 installs
a trigger rejecting UPDATE and DELETE on the events table, so a leaked runtime
credential can append but cannot rewrite or erase the trail. That materially
narrows the residual risk ADR-0001 section 5 called out. tamper_evidence stays
False because nothing here would prove a database owner had dropped the
trigger - hash-chaining or external anchoring would be needed and is not
implemented.
Idempotency is one statement (INSERT ... ON CONFLICT DO NOTHING RETURNING),
verified to behave identically to the SQLite backend under 12 concurrent
submissions of the same event. Migrations are ordered, recorded and
idempotent. Replay reconciles rather than duplicating - the piece deferred out
of WP-0004-T05 - and is tested to leave exactly one custody record.
Backend selection is by AUDIT_CORE_DATABASE_URL; the SQLite fallback logs a
warning so a deployment that lost its URL is visible rather than quietly
running on the wrong store.
Also fixed: ingestion had no __main__ guard, so python -m audit_core.ingestion
silently did nothing. Found during end-to-end smoke.
Counting semantics documented: occurrences counts transmissions, not stored
events, so a retry of a secret-shaped field increments it again. That is the
sender behaviour being optimized away.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
AUDIT-WP-0004 T01, T02, T07.
T01 - ingestion wrote to SQLite directly and never called the AuditBackend
contract, so a 202 meant a row existed rather than that a backend with a
declared retention policy had accepted the event. Adds IdempotentAuditBackend
to the contract: duplicate detection lives inside the backend so custody and
idempotency state share a transaction and cannot diverge. SQLiteAuditBackend
implements it with WAL, synchronous=FULL and a busy timeout. Ingestion now
refuses any backend declaring durable=False, so the development file backend
cannot silently become the production sink.
The atomicity claim was tested rather than asserted, and the first attempt
failed: with a single shared connection, 16 racing submissions of one event
told two callers they were first. Storage was correct but the response was
not. Fixed with per-thread connections and BEGIN IMMEDIATE around the
insert/read pair, and locked in by a test.
T02 - storage errors previously escaped the handler with start_response never
called, and the auth check sat outside the try block so a non-ASCII
Authorization header crashed the request. Adds a catch-all, maps conflict to
409, backend unavailability to 503 and unexpected faults to 500, and
documents the full response contract with the retry semantics each status
implies, since senders key their behaviour off it.
T07 - ingestion tests 2 -> 23, suite 15 -> 36. accepted_at is now UTC rather
than local time, and naive timestamps are rejected instead of silently
assumed.
Remaining in WP-0004: T03 tenant/source binding, T04 redaction policy,
T05 operator read surface, T06 production serving layer.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A pre-deploy review found the receiver is not deployable as built. The
ingestion path never calls AuditBackend.emit(), so a 202 means a SQLite row
exists, not that a backend with a declared retention policy accepted the
event. Storage exceptions escape the handler with start_response never
called. Tenant isolation and source binding are recorded as done but are not
implemented. There is no read, replay, or correlation-lookup surface, so the
failure matrix cannot produce the evidence NK-WP-0024 needs.
WP-0003 closes as finished on its narrowed scope (contract + reference
implementation, T01/T02). T03 and T04 are cancelled with rationale.
WP-0004 covers receiver correctness and hardening, storage-agnostic so it
runs in parallel with the database platform work.
WP-0005 covers the Postgres backend, deployment, SQLite record migration,
and the live failure matrix. Production storage moves from SQLite-on-a-volume
to the Railiance PostgreSQL platform (RAPP-POSTGRES-WP-0002).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
