fix(api): restore Alertmanager project context

apps/api/src/main.py

@@ -120,6 +120,26 @@ from src.workers import close_signal_worker, init_signal_worker
 setup_logging()
 logger = get_logger("awoooi.api")
 
+ALERTMANAGER_WEBHOOK_PATH = "/api/v1/webhooks/alertmanager"
+ALERTMANAGER_DEFAULT_PROJECT_ID = "awoooi"
+
+
+def _resolve_request_project_context(request: Request) -> tuple[str | None, str]:
+    """Resolve tenant context for RLS while keeping non-webhook routes fail-closed."""
+    for candidate in (
+        request.headers.get("X-Project-ID"),
+        request.headers.get("X-Tenant-ID"),
+        request.query_params.get("project_id"),
+    ):
+        project_id = candidate.strip() if candidate else None
+        if project_id:
+            return project_id, "request.header_or_query"
+
+    if request.url.path == ALERTMANAGER_WEBHOOK_PATH:
+        return ALERTMANAGER_DEFAULT_PROJECT_ID, "request.alertmanager.default_project"
+
+    return None, "request.project_id.missing"
+
 # =============================================================================
 # Sentry SDK Initialization (Error Tracking - 補強 SignOz)
 # Self-Hosted @ 192.168.0.110
@@ -905,15 +925,7 @@ async def request_logging_middleware(request: Request, call_next):
     from src.core.context import clear_project_context, get_current_project_context, set_project_context
 
     request_id = request.headers.get("X-Request-ID") or str(uuid4())
-    project_id = (
-        request.headers.get("X-Project-ID")
-        or request.headers.get("X-Tenant-ID")
-        or request.query_params.get("project_id")
-    )
-    project_id = project_id.strip() if project_id else None
-    source = "request.project_id.missing"
-    if project_id:
-        source = "request.header_or_query"
+    project_id, source = _resolve_request_project_context(request)
 
     context_tokens = set_project_context(
         project_id=project_id,

apps/api/tests/test_alertmanager_project_context.py

@@ -0,0 +1,55 @@
+from __future__ import annotations
+
+from starlette.requests import Request
+
+from src.main import _resolve_request_project_context
+
+
+def _request(
+    path: str,
+    *,
+    query_string: bytes = b"",
+    headers: list[tuple[bytes, bytes]] | None = None,
+) -> Request:
+    return Request(
+        {
+            "type": "http",
+            "method": "POST",
+            "path": path,
+            "scheme": "http",
+            "server": ("testserver", 80),
+            "client": ("127.0.0.1", 50000),
+            "query_string": query_string,
+            "headers": headers or [],
+        }
+    )
+
+
+def test_alertmanager_webhook_without_header_uses_awoooi_project_context():
+    project_id, source = _resolve_request_project_context(
+        _request("/api/v1/webhooks/alertmanager")
+    )
+
+    assert project_id == "awoooi"
+    assert source == "request.alertmanager.default_project"
+
+
+def test_alertmanager_webhook_keeps_explicit_project_context_priority():
+    project_id, source = _resolve_request_project_context(
+        _request(
+            "/api/v1/webhooks/alertmanager",
+            headers=[(b"x-project-id", b"tenant-a")],
+        )
+    )
+
+    assert project_id == "tenant-a"
+    assert source == "request.header_or_query"
+
+
+def test_non_alertmanager_route_without_header_still_fails_closed():
+    project_id, source = _resolve_request_project_context(
+        _request("/api/v1/security/db-context-guard")
+    )
+
+    assert project_id is None
+    assert source == "request.project_id.missing"