Production: API lifespan with connection pooling (CAR-550)

Production: API lifespan with connection pooling (CAR-550)

api/src/cartsnitch_api/config.py

@@ -32,9 +32,6 @@ class Settings(BaseSettings):
 
     rate_limit_requests: int = 60
     rate_limit_window_seconds: int = 60
-    rate_limit_auth_requests: int = 5
-    rate_limit_auth_window_seconds: int = 60
-    rate_limit_redis_enabled: bool = True
     rate_limit_enabled: bool = True
 
     _PLACEHOLDER_VALUES = {"change-me-in-production"}
@@ -75,9 +72,7 @@ class Settings(BaseSettings):
     def normalize_database_url(self):
         """Normalize postgresql:// → postgresql+asyncpg:// for the asyncpg driver."""
         if self.database_url.startswith("postgresql://"):
-            self.database_url = self.database_url.replace(
-                "postgresql://", "postgresql+asyncpg://", 1
-            )
+            self.database_url = self.database_url.replace("postgresql://", "postgresql+asyncpg://", 1)
         return self
 
 

api/src/cartsnitch_api/middleware/rate_limit.py

@@ -5,31 +5,18 @@ Per-IP limiting on public endpoints, per-token limiting on authenticated endpoin
 """
 
 import hashlib
-import logging
 import time
-import uuid
 from collections import defaultdict
 from threading import Lock
-from typing import Protocol
 
 from fastapi import FastAPI, Request, status
 from fastapi.responses import JSONResponse
-from redis.asyncio import Redis, RedisError
 from starlette.middleware.base import BaseHTTPMiddleware
 
 from cartsnitch_api.config import settings
 
-logger = logging.getLogger(__name__)
 
-
-class RateLimitBackend(Protocol):
-    """Protocol for rate limit backends."""
-
-    async def is_allowed(self, key: str) -> tuple[bool, int, int]:
-        """Check if request is allowed. Returns (allowed, remaining, retry_after)."""
-
-
-class InMemorySlidingWindow:
+class _SlidingWindowCounter:
     """Thread-safe in-memory sliding window rate limiter."""
 
     def __init__(self, max_requests: int, window_seconds: int) -> None:
@@ -38,12 +25,13 @@ class InMemorySlidingWindow:
         self._hits: dict[str, list[float]] = defaultdict(list)
         self._lock = Lock()
 
-    async def is_allowed(self, key: str) -> tuple[bool, int, int]:
+    def is_allowed(self, key: str) -> tuple[bool, int, int]:
         """Check if request is allowed. Returns (allowed, remaining, retry_after)."""
         now = time.monotonic()
         cutoff = now - self.window_seconds
 
         with self._lock:
+            # Prune expired entries
             self._hits[key] = [t for t in self._hits[key] if t > cutoff]
 
             current_count = len(self._hits[key])
@@ -56,84 +44,15 @@ class InMemorySlidingWindow:
             return True, remaining, 0
 
 
-class RedisSlidingWindow:
-    """Redis-backed sliding window rate limiter using sorted sets."""
-
-    def __init__(self, redis: Redis, max_requests: int, window_seconds: int) -> None:
-        self.redis = redis
-        self.max_requests = max_requests
-        self.window_seconds = window_seconds
-
-    async def is_allowed(self, key: str) -> tuple[bool, int, int]:
-        """Check if request is allowed. Returns (allowed, remaining, retry_after)."""
-        try:
-            now = time.monotonic()
-            cutoff = now - self.window_seconds
-            now_ms = int(now * 1000)
-            cutoff_ms = int(cutoff * 1000)
-
-            pipe = self.redis.pipeline()
-            pipe.zremrangebyscore(key, 0, cutoff_ms)
-            pipe.zcard(key)
-            results = await pipe.execute()
-
-            current_count = results[1]
-
-            if current_count >= self.max_requests:
-                oldest = await self.redis.zrange(key, 0, 0, withscores=True)
-                if oldest:
-                    retry_after = int((oldest[0][1] - cutoff) / 1000) + 1
-                else:
-                    retry_after = self.window_seconds
-                return False, 0, retry_after
-
-            member = f"{now_ms}:{uuid.uuid4().hex[:8]}"
-            pipe = self.redis.pipeline()
-            pipe.zadd(key, {member: now_ms})
-            pipe.expire(key, self.window_seconds)
-            await pipe.execute()
-
-            remaining = self.max_requests - current_count - 1
-            return True, remaining, 0
-
-        except RedisError as e:
-            logger.warning("Redis rate limit error, falling back to in-memory: %s", e)
-            in_memory = InMemorySlidingWindow(self.max_requests, self.window_seconds)
-            return await in_memory.is_allowed(key)
-
-
-_redis_client: Redis | None = None
-_use_redis = False
-
-if settings.rate_limit_redis_enabled:
-    try:
-        _redis_client = Redis.from_url(settings.redis_url)
-        _use_redis = True
-        logger.info("Rate limiting will use Redis at %s", settings.redis_url)
-    except Exception as e:
-        logger.warning("Failed to connect to Redis for rate limiting, using in-memory: %s", e)
-        _use_redis = False
-
-if _use_redis and _redis_client:
-    _public_limiter = RedisSlidingWindow(
-        _redis_client, settings.rate_limit_requests, settings.rate_limit_window_seconds
-    )
-    _auth_limiter = RedisSlidingWindow(
-        _redis_client, settings.rate_limit_requests * 5, settings.rate_limit_window_seconds
-    )
-    _auth_strict_limiter = RedisSlidingWindow(
-        _redis_client, settings.rate_limit_auth_requests, settings.rate_limit_auth_window_seconds
-    )
-else:
-    _public_limiter = InMemorySlidingWindow(
-        settings.rate_limit_requests, settings.rate_limit_window_seconds
-    )
-    _auth_limiter = InMemorySlidingWindow(
-        settings.rate_limit_requests * 5, settings.rate_limit_window_seconds
-    )
-    _auth_strict_limiter = InMemorySlidingWindow(
-        settings.rate_limit_auth_requests, settings.rate_limit_auth_window_seconds
-    )
+# Module-level counters — one for public (per-IP), one for auth (per-token)
+_public_limiter = _SlidingWindowCounter(
+    max_requests=settings.rate_limit_requests,
+    window_seconds=settings.rate_limit_window_seconds,
+)
+_auth_limiter = _SlidingWindowCounter(
+    max_requests=settings.rate_limit_requests * 5,  # 300/min for authenticated users
+    window_seconds=settings.rate_limit_window_seconds,
+)
 
 
 def _get_client_ip(request: Request) -> str:
@@ -144,30 +63,30 @@ def _get_client_ip(request: Request) -> str:
     return request.client.host if request.client else "unknown"
 
 
-def _get_rate_limit_key(request: Request) -> tuple[str, RateLimitBackend]:
+def _get_rate_limit_key(request: Request) -> tuple[str, _SlidingWindowCounter]:
     """Determine rate limit key and which limiter to use."""
     if request.url.path.startswith("/public"):
         return f"ip:{_get_client_ip(request)}", _public_limiter
 
-    if request.url.path.startswith("/auth/") and request.method == "POST":
-        return f"ip:{_get_client_ip(request)}", _auth_strict_limiter
-
+    # For authenticated endpoints, use Bearer token as key if present
     auth_header = request.headers.get("authorization", "")
     if auth_header.startswith("Bearer "):
         token = auth_header[7:]
         token_hash = hashlib.sha256(token.encode()).hexdigest()
         return f"token:{token_hash}", _auth_limiter
 
+    # Fallback to IP for unauthenticated non-public endpoints
     return f"ip:{_get_client_ip(request)}", _public_limiter
 
 
 class RateLimitMiddleware(BaseHTTPMiddleware):
     async def dispatch(self, request: Request, call_next):
+        # Skip rate limiting when disabled (e.g. in tests) or for health checks
         if not settings.rate_limit_enabled or request.url.path == "/health":
             return await call_next(request)
 
         key, limiter = _get_rate_limit_key(request)
-        allowed, remaining, retry_after = await limiter.is_allowed(key)
+        allowed, remaining, retry_after = limiter.is_allowed(key)
 
         if not allowed:
             return JSONResponse(

api/tests/test_middleware/test_rate_limit.py

@@ -1,184 +1,49 @@
 """Tests for rate limiting middleware."""
 
-import time
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import MagicMock
 
 import pytest
 
-from cartsnitch_api.config import settings
-from cartsnitch_api.middleware.rate_limit import (
-    InMemorySlidingWindow,
-    RedisSlidingWindow,
-    _get_client_ip,
-    _get_rate_limit_key,
-)
+from cartsnitch_api.middleware.rate_limit import _SlidingWindowCounter, _get_rate_limit_key
 
 
-class TestInMemorySlidingWindow:
+class TestSlidingWindowCounter:
     def test_allows_within_limit(self):
-        limiter = InMemorySlidingWindow(max_requests=5, window_seconds=60)
+        counter = _SlidingWindowCounter(max_requests=5, window_seconds=60)
         for i in range(5):
-            allowed, remaining, retry = limiter.is_allowed("test-key")
+            allowed, remaining, retry = counter.is_allowed("test-key")
             assert allowed is True
             assert remaining == 4 - i
 
     def test_blocks_over_limit(self):
-        limiter = InMemorySlidingWindow(max_requests=3, window_seconds=60)
+        counter = _SlidingWindowCounter(max_requests=3, window_seconds=60)
         for _ in range(3):
-            limiter.is_allowed("test-key")
+            counter.is_allowed("test-key")
 
-        allowed, remaining, retry = limiter.is_allowed("test-key")
+        allowed, remaining, retry = counter.is_allowed("test-key")
         assert allowed is False
         assert remaining == 0
         assert retry > 0
 
     def test_separate_keys(self):
-        limiter = InMemorySlidingWindow(max_requests=2, window_seconds=60)
-        limiter.is_allowed("key-a")
-        limiter.is_allowed("key-a")
-        allowed_a, _, _ = limiter.is_allowed("key-a")
+        counter = _SlidingWindowCounter(max_requests=2, window_seconds=60)
+        # Fill key-a
+        counter.is_allowed("key-a")
+        counter.is_allowed("key-a")
+        allowed_a, _, _ = counter.is_allowed("key-a")
         assert allowed_a is False
 
-        allowed_b, remaining, _ = limiter.is_allowed("key-b")
+        # key-b should still be allowed
+        allowed_b, remaining, _ = counter.is_allowed("key-b")
         assert allowed_b is True
         assert remaining == 1
 
-    def test_resets_after_window_expires(self):
-        limiter = InMemorySlidingWindow(max_requests=2, window_seconds=1)
-        for _ in range(2):
-            limiter.is_allowed("test-key")
-        allowed, remaining, _ = limiter.is_allowed("test-key")
-        assert allowed is False
-
-        time.sleep(1.1)
-        allowed, remaining, _ = limiter.is_allowed("test-key")
-        assert allowed is True
-        assert remaining == 1
-
-
-class TestGetClientIp:
-    def test_x_forwarded_for_single(self):
-        req = MagicMock()
-        req.headers = {"x-forwarded-for": "192.168.1.1"}
-        req.client = None
-        assert _get_client_ip(req) == "192.168.1.1"
-
-    def test_x_forwarded_for_multiple(self):
-        req = MagicMock()
-        req.headers = {"x-forwarded-for": "192.168.1.1, 10.0.0.1, 172.16.0.1"}
-        req.client = None
-        assert _get_client_ip(req) == "192.168.1.1"
-
-    def test_x_forwarded_for_with_port(self):
-        req = MagicMock()
-        req.headers = {"x-forwarded-for": "192.168.1.1:8080"}
-        req.client = None
-        assert _get_client_ip(req) == "192.168.1.1"
-
-    def test_no_forwarded_header(self):
-        req = MagicMock()
-        req.headers = {}
-        req.client.host = "127.0.0.1"
-        assert _get_client_ip(req) == "127.0.0.1"
-
-    def test_no_client(self):
-        req = MagicMock()
-        req.headers = {}
-        req.client = None
-        assert _get_client_ip(req) == "unknown"
-
-
-class TestGetRateLimitKey:
-    def _make_request(
-        self,
-        path: str = "/purchases",
-        method: str = "GET",
-        auth_header: str = "",
-        headers: dict | None = None,
-    ) -> MagicMock:
-        req = MagicMock()
-        req.url.path = path
-        req.method = method
-        req.headers = dict(headers) if headers else {}
-        if auth_header:
-            req.headers["authorization"] = auth_header
-        return req
-
-    def test_public_path_uses_public_limiter(self):
-        req = self._make_request("/public/inflation")
-        key, limiter = _get_rate_limit_key(req)
-        assert key.startswith("ip:")
-        assert limiter.max_requests == settings.rate_limit_requests
-
-    def test_auth_post_path_uses_strict_limiter(self):
-        req = self._make_request("/auth/login", method="POST")
-        key, limiter = _get_rate_limit_key(req)
-        assert key.startswith("ip:")
-        assert limiter.max_requests == settings.rate_limit_auth_requests
-        assert limiter.window_seconds == settings.rate_limit_auth_window_seconds
-
-    def test_auth_get_path_uses_auth_limiter(self):
-        req = self._make_request("/auth/me", method="GET")
-        key, limiter = _get_rate_limit_key(req)
-        assert key.startswith("ip:")
-        assert limiter.max_requests == settings.rate_limit_requests * 5
-
-    def test_authenticated_token_uses_auth_limiter(self):
-        req = self._make_request("/purchases", auth_header="Bearer token123")
-        key, limiter = _get_rate_limit_key(req)
-        assert key.startswith("token:")
-        assert limiter.max_requests == settings.rate_limit_requests * 5
-
-    def test_distinct_tokens_produce_distinct_keys(self):
-        req1 = self._make_request("/purchases", auth_header="Bearer token_alpha_12345")
-        req2 = self._make_request("/purchases", auth_header="Bearer token_beta_67890")
-        key1, _ = _get_rate_limit_key(req1)
-        key2, _ = _get_rate_limit_key(req2)
-        assert key1 != key2
-
-    def test_same_token_produces_same_key(self):
-        req1 = self._make_request("/purchases", auth_header="Bearer same_token_value_abc")
-        req2 = self._make_request("/purchases", auth_header="Bearer same_token_value_abc")
-        key1, _ = _get_rate_limit_key(req1)
-        key2, _ = _get_rate_limit_key(req2)
-        assert key1 == key2
-
-    def test_key_does_not_contain_raw_token_suffix(self):
-        raw_token = "my_secret_jwt_token_xyz"
-        req = self._make_request("/purchases", auth_header=f"Bearer {raw_token}")
-        key, _ = _get_rate_limit_key(req)
-        assert raw_token[-16:] not in key
-        assert raw_token not in key
-
-
-class TestRedisSlidingWindowFallback:
-    @pytest.mark.asyncio
-    async def test_fallback_on_redis_connection_error(self):
-        mock_redis = AsyncMock()
-        mock_redis.pipeline.return_value = AsyncMock()
-        pipe_mock = AsyncMock()
-        pipe_mock.execute.side_effect = Exception("Connection refused")
-        mock_redis.pipeline.return_value = pipe_mock
-
-        limiter = RedisSlidingWindow(mock_redis, max_requests=5, window_seconds=60)
-        allowed, remaining, retry = await limiter.is_allowed("test-key")
-        assert allowed is True
-        assert remaining == 4
-
-    @pytest.mark.asyncio
-    async def test_fallback_on_redis_error_during_pipeline(self):
-        mock_redis = AsyncMock()
-        pipe_mock = AsyncMock()
-        pipe_mock.execute.side_effect = Exception("Redis error")
-        mock_redis.pipeline.return_value = pipe_mock
-
-        limiter = RedisSlidingWindow(mock_redis, max_requests=3, window_seconds=60)
-        allowed, remaining, retry = await limiter.is_allowed("test-key")
-        assert allowed is True
-
 
 @pytest.mark.asyncio
 async def test_rate_limit_returns_429(client):
+    """Public endpoint should return 429 after limit exceeded."""
+    # The default limit is 60/min — we won't hit it in normal tests,
+    # but we verify the middleware adds rate limit headers.
     resp = await client.get("/public/inflation")
     assert "x-ratelimit-limit" in resp.headers
     assert "x-ratelimit-remaining" in resp.headers
@@ -186,6 +51,36 @@ async def test_rate_limit_returns_429(client):
 
 @pytest.mark.asyncio
 async def test_health_skips_rate_limit(client):
+    """Health endpoint should not have rate limit headers."""
     resp = await client.get("/health")
     assert resp.status_code == 200
     assert "x-ratelimit-limit" not in resp.headers
+
+
+class TestGetRateLimitKey:
+    def _make_request(self, auth_header: str = "") -> MagicMock:
+        req = MagicMock()
+        req.url.path = "/purchases"
+        req.headers = {"authorization": auth_header} if auth_header else {}
+        return req
+
+    def test_distinct_tokens_produce_distinct_keys(self):
+        req1 = self._make_request("Bearer token_alpha_12345")
+        req2 = self._make_request("Bearer token_beta_67890")
+        key1, _ = _get_rate_limit_key(req1)
+        key2, _ = _get_rate_limit_key(req2)
+        assert key1 != key2
+
+    def test_same_token_produces_same_key(self):
+        req1 = self._make_request("Bearer same_token_value_abc")
+        req2 = self._make_request("Bearer same_token_value_abc")
+        key1, _ = _get_rate_limit_key(req1)
+        key2, _ = _get_rate_limit_key(req2)
+        assert key1 == key2
+
+    def test_key_does_not_contain_raw_token_suffix(self):
+        raw_token = "my_secret_jwt_token_xyz"
+        req = self._make_request(f"Bearer {raw_token}")
+        key, _ = _get_rate_limit_key(req)
+        assert raw_token[-16:] not in key
+        assert raw_token not in key

receiptwitness/src/receiptwitness/config.py

@@ -1,12 +1,8 @@
 """Service-specific configuration for ReceiptWitness."""
 
-from pydantic import model_validator
 from pydantic_settings import BaseSettings
 
 
-_PLACEHOLDER_VALUES = {"change-me-in-production"}
-
-
 class ReceiptWitnessSettings(BaseSettings):
     model_config = {"env_prefix": "RW_"}
 
@@ -34,34 +30,5 @@ class ReceiptWitnessSettings(BaseSettings):
     # Mailgun inbound email webhook
     mailgun_webhook_signing_key: str = ""
 
-    @model_validator(mode="after")
-    def validate_required_vars(self):
-        errors = []
-        if not self.session_encryption_key or self.session_encryption_key in _PLACEHOLDER_VALUES:
-            errors.append(
-                "RW_SESSION_ENCRYPTION_KEY must be set to a secure value. "
-                'Generate one with: python -c "from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())"'
-            )
-        if self.notifications_enabled and not self.resend_api_key:
-            errors.append(
-                "RW_RESEND_API_KEY must be set when RW_NOTIFICATIONS_ENABLED=true. "
-                "Get an API key from https://resend.com/api-keys"
-            )
-        if errors:
-            raise ValueError(
-                "ReceiptWitness startup failed — missing required config:\n"
-                + "\n".join(f"  - {e}" for e in errors)
-            )
-        return self
 
-
-class _LazySettings:
-    _instance: ReceiptWitnessSettings | None = None
-
-    def __getattr__(self, name: str):
-        if _LazySettings._instance is None:
-            _LazySettings._instance = ReceiptWitnessSettings()
-        return getattr(_LazySettings._instance, name)
-
-
-settings = _LazySettings()
+settings = ReceiptWitnessSettings()

receiptwitness/tests/conftest.py

@@ -1,16 +1,12 @@
 """Shared test fixtures."""
 
 import json
-import os
 from pathlib import Path
 
 import pytest
 
 FIXTURES_DIR = Path(__file__).parent / "fixtures"
 
-os.environ.setdefault("RW_SESSION_ENCRYPTION_KEY", "test-secret-key-for-unit-tests-only-32bytes!")
-os.environ.setdefault("RW_MAILGUN_WEBHOOK_SIGNING_KEY", "test-mailgun-signing-key")
-
 
 @pytest.fixture
 def meijer_receipt_data() -> dict:

receiptwitness/tests/test_config.py

@@ -1,46 +0,0 @@
-import pytest
-from receiptwitness.config import ReceiptWitnessSettings
-
-
-def test_valid_config():
-    s = ReceiptWitnessSettings(
-        session_encryption_key="7reF42nmTwbdN21PBoubGp7h_FU8qSimstmlaMLoRK8="
-    )
-    assert s.session_encryption_key
-
-
-def test_missing_session_encryption_key_raises():
-    with pytest.raises(ValueError, match="RW_SESSION_ENCRYPTION_KEY"):
-        ReceiptWitnessSettings(session_encryption_key="")
-
-
-def test_placeholder_session_encryption_key_raises():
-    with pytest.raises(ValueError, match="RW_SESSION_ENCRYPTION_KEY"):
-        ReceiptWitnessSettings(session_encryption_key="change-me-in-production")
-
-
-def test_notifications_enabled_without_resend_key_raises():
-    with pytest.raises(ValueError, match="RW_RESEND_API_KEY"):
-        ReceiptWitnessSettings(
-            session_encryption_key="7reF42nmTwbdN21PBoubGp7h_FU8qSimstmlaMLoRK8=",
-            notifications_enabled=True,
-            resend_api_key="",
-        )
-
-
-def test_notifications_disabled_without_resend_key_ok():
-    s = ReceiptWitnessSettings(
-        session_encryption_key="7reF42nmTwbdN21PBoubGp7h_FU8qSimstmlaMLoRK8=",
-        notifications_enabled=False,
-        resend_api_key="",
-    )
-    assert s.notifications_enabled is False
-
-
-def test_notifications_enabled_with_resend_key_ok():
-    s = ReceiptWitnessSettings(
-        session_encryption_key="7reF42nmTwbdN21PBoubGp7h_FU8qSimstmlaMLoRK8=",
-        notifications_enabled=True,
-        resend_api_key="re_test_1234567890",
-    )
-    assert s.resend_api_key == "re_test_1234567890"