Add AI engine load balancer authentication

engine/tests/test_user_context.py

@@ -0,0 +1,50 @@
+"""Tests for UserIdMiddleware - X-User-Id propagates as context.
+
+X-Tenant-Id is deliberately NOT accepted from the wire: the Java proxy does not stamp
+one and a client-supplied tenant id would be spoofable. If/when tenant scoping arrives
+it must be derived from the server-side security context, not from request headers.
+"""
+from __future__ import annotations
+
+from fastapi import FastAPI, Request
+from fastapi.testclient import TestClient
+
+from stirling.api.middleware import UserIdMiddleware
+from stirling.services.tracking import current_user_id
+
+
+def _app() -> FastAPI:
+    app = FastAPI()
+    app.add_middleware(UserIdMiddleware)
+
+    @app.get("/me")
+    async def me(request: Request):
+        return {
+            "user_id": current_user_id.get(),
+            "tenant_id": getattr(request.state, "tenant_id", None),
+        }
+
+    return app
+
+
+def test_user_id_header_is_propagated():
+    client = TestClient(_app())
+    res = client.get("/me", headers={"X-User-Id": "alice"})
+    assert res.status_code == 200
+    assert res.json()["user_id"] == "alice"
+
+
+def test_tenant_id_header_is_ignored():
+    client = TestClient(_app())
+    res = client.get("/me", headers={"X-User-Id": "alice", "X-Tenant-Id": "acme"})
+    assert res.status_code == 200
+    body = res.json()
+    assert body["user_id"] == "alice"
+    assert body["tenant_id"] is None
+
+
+def test_missing_user_id_returns_no_user_in_context():
+    client = TestClient(_app())
+    res = client.get("/me")
+    assert res.status_code == 200
+    assert res.json()["user_id"] in ("", None)