Implement Phase 0b base project against the frozen test contract
All seven services (gateway, ledger, fraud, sanctions, insights, notifier, audit), db/schema.sql plus optional_indexes.sql, scripts/seed.py and smoke.py, the gateway-served frontend, and docker-compose.yml. Plain-text stdlib logging and a weak manual X-Request-Id only -- no observability yet, by design, per test_no_observability.py. Implements all 13 named chaos-flag pathologies from docs/PATHOLOGIES.md behind Redis-backed runtime flags. make smoke and make test-contract pass; make test-baseline and make test-pathology pass except for a handful of load-sensitive tests documented in tests/README.md rather than papered over.
This commit is contained in:
Movses Aslanyan
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import logging
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import time
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import uuid
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import httpx
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from common.http import downstream_client
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from common.redis_client import redis_client
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from common.settings import settings
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from . import chaos
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logger = logging.getLogger("gateway")
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REJECT_THRESHOLD = 0.8
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class UpstreamFailure(Exception):
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def __init__(self, status_code: int, message: str):
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self.status_code = status_code
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self.message = message
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async def _post(client: httpx.AsyncClient, url: str, json: dict) -> httpx.Response:
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try:
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return await client.post(url, json=json)
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except httpx.TimeoutException as exc:
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raise UpstreamFailure(504, f"{url} timed out") from exc
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except httpx.RequestError as exc:
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raise UpstreamFailure(502, f"{url} unreachable") from exc
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async def _score_once(client: httpx.AsyncClient, payload: dict) -> dict:
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resp = await _post(client, f"{settings.fraud_url}/internal/score", payload)
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if resp.status_code >= 300:
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status = resp.status_code if resp.status_code in (502, 504) else 502
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raise UpstreamFailure(status, "fraud scoring failed")
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return resp.json()
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async def _score_with_retry(client: httpx.AsyncClient, payload: dict, retry_storm: bool) -> dict:
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"""retry_storm: on any non-2xx from fraud, retry 3 times immediately --
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no backoff, no jitter, no circuit breaker (phase-0-base-project-spec.md §7).
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"No circuit breaker" is taken literally here: once triggered, it fires all
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3 retries unconditionally rather than stopping early on the first success
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-- it never checks whether it still needs to. The last attempt's outcome
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wins."""
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attempts = 4 if retry_storm else 1
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result = None
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last_exc = None
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for _ in range(attempts):
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try:
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result = await _score_once(client, payload)
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last_exc = None
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except UpstreamFailure as exc:
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last_exc = exc
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if last_exc is not None:
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raise last_exc
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return result
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async def _run_chatty_health_probe(client: httpx.AsyncClient) -> None:
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"""chatty_health: GET /healthz on all five downstreams, sequentially,
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before doing any real work."""
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headers = {"X-Ledgerline-Probe": "chatty-health"}
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for name in chaos.DOWNSTREAMS:
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url = getattr(settings, f"{name}_url")
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try:
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await client.get(f"{url}/healthz", headers=headers, timeout=2.0)
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except httpx.RequestError:
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pass
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async def create_transaction(payload: dict, request_id: str) -> dict:
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start = time.perf_counter()
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logger.info(f"start transaction for account {payload['account_id']} request_id={request_id}")
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retry_storm = await chaos.retry_storm_enabled()
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no_batching = await chaos.no_batching_enabled()
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chatty_health = await chaos.chatty_health_enabled()
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async with downstream_client(request_id) as client:
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if chatty_health:
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await _run_chatty_health_probe(client)
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create_resp = await _post(
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client,
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f"{settings.ledger_url}/internal/transactions",
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{**payload, "request_id": request_id},
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)
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if create_resp.status_code == 404:
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raise UpstreamFailure(404, "account not found")
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if create_resp.status_code >= 500:
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raise UpstreamFailure(create_resp.status_code, "ledger failed unexpectedly")
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if create_resp.status_code >= 300:
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raise UpstreamFailure(502, "ledger rejected the transaction")
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created = create_resp.json()
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tx_id = created["transaction_id"]
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score_payload = {
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"account_id": created["account_id"],
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"holder_name": created["holder_name"],
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"category_id": created["category_id"],
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"request_id": request_id,
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}
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if no_batching:
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item_count = chaos.synthetic_line_item_count()
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scores = []
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for _ in range(item_count):
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item_payload = {**score_payload, "amount_minor": max(1, created["amount_minor"] // item_count)}
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scores.append(await _score_with_retry(client, item_payload, retry_storm))
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risk_score = max(s["risk_score"] for s in scores)
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else:
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score_payload["amount_minor"] = created["amount_minor"]
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scored = await _score_with_retry(client, score_payload, retry_storm)
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risk_score = scored["risk_score"]
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decision = "rejected" if risk_score > REJECT_THRESHOLD else "settled"
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action = "reject" if decision == "rejected" else "settle"
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settle_resp = await _post(
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client,
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f"{settings.ledger_url}/internal/transactions/{tx_id}/{action}",
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{"risk_score": risk_score, "request_id": request_id},
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)
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if settle_resp.status_code >= 300:
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raise UpstreamFailure(502, "ledger failed to finalise the transaction")
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settled = settle_resp.json()
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try:
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await redis_client.xadd(
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settings.stream_name,
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{
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"transaction_id": tx_id,
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"account_id": created["account_id"],
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"kind": created["kind"],
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"amount_minor": str(created["amount_minor"]),
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"status": settled["status"],
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"risk_score": str(risk_score),
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},
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)
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except Exception:
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logger.exception(f"failed to publish transaction {tx_id} to the stream")
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summary = {}
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try:
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summary_resp = await client.get(
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f"{settings.insights_url}/internal/accounts/{created['account_id']}/quick_summary"
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)
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if summary_resp.status_code == 200:
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summary = summary_resp.json()
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except httpx.RequestError:
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logger.exception(f"insights summary unavailable for request_id={request_id}")
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elapsed_ms = (time.perf_counter() - start) * 1000
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logger.info(f"finished transaction {tx_id} status={settled['status']} request_id={request_id}")
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return {
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"transaction_id": tx_id,
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"status": settled["status"],
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"risk_score": risk_score,
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"balance_minor": settled["balance_minor"],
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"summary": summary,
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"request_id": request_id,
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"elapsed_ms": elapsed_ms,
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}
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