fix(api): await Kafka acknowledgements and bound HTTP requests

tests/test_api_delivery.py

@@ -0,0 +1,72 @@
+import asyncio
+import json
+import unittest
+from concurrent.futures import Future
+
+from app.api.producer import MockMessageProducer
+from app.api.server import IngestionAPIServer
+
+
+def payload():
+    return dict(raw_id="delivery-test", device_id="123", caller_num="+19875551234",
+                svc="4G_DATA", rat=6, lac="1", ci="2", up_bytes=10,
+                down_bytes=20, epoch_start=1726070000, epoch_end=1726070300)
+
+
+class PendingProducer(MockMessageProducer):
+    def __init__(self):
+        super().__init__()
+        self.pending = []
+
+    def produce(self, topic, key, value):
+        future = Future()
+        self.pending.append(future)
+        return future
+
+
+class Writer:
+    def __init__(self):
+        self.data = b""
+
+    def write(self, value):
+        self.data += value
+
+    async def drain(self):
+        pass
+
+
+class TestAcknowledgedAPI(unittest.IsolatedAsyncioTestCase):
+    async def test_response_waits_for_delivery_and_bounds_outstanding(self):
+        producer = PendingProducer()
+        server = IngestionAPIServer(producer=producer, queue_max_size=1)
+        writer = Writer()
+        task = asyncio.create_task(server._handle_raw_cdr_ingestion(writer, json.dumps(payload()).encode()))
+        await asyncio.sleep(0.02)
+        self.assertEqual(writer.data, b"", "202 must await the broker")
+        other = Writer()
+        await server._handle_raw_cdr_ingestion(other, json.dumps(payload()).encode())
+        self.assertIn(b"429", other.data)
+        producer.pending[0].set_result(None)
+        await task
+        self.assertIn(b"202", writer.data)
+
+    async def test_missing_fields_wrong_types_and_utf8_return_400(self):
+        server = IngestionAPIServer(producer=MockMessageProducer())
+        for body in (b"{}", b"\xff", json.dumps(payload() | {"raw_id": 42}).encode(),
+                     json.dumps(payload() | {"rat": True}).encode()):
+            with self.subTest(body=body):
+                writer = Writer()
+                await server._handle_raw_cdr_ingestion(writer, body)
+                self.assertIn(b"400", writer.data)
+
+    async def test_failed_delivery_returns_503_and_next_request_recovers(self):
+        producer = MockMessageProducer()
+        server = IngestionAPIServer(producer=producer)
+        producer.set_healthy(False)
+        writer = Writer()
+        await server._handle_raw_cdr_ingestion(writer, json.dumps(payload()).encode())
+        self.assertIn(b"503", writer.data)
+        producer.set_healthy(True)
+        writer = Writer()
+        await server._handle_raw_cdr_ingestion(writer, json.dumps(payload()).encode())
+        self.assertIn(b"202", writer.data)