commit inital example

examples/fastapi.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env python
+
+# This is just hello_world.py integrated with a FastAPI application
+
+import mode.loop.uvloop  # noqa
+
+import faust
+
+from contextlib import asynccontextmanager
+
+from fastapi import FastAPI
+
+
+def fake_answer_to_everything_ml_model(x: float):
+    return x * 42
+
+
+ml_models = {}
+
+
+# You MUST have "app" defined
+app = faust_app = faust.App(
+    'hello-world-fastapi',
+    broker='kafka://localhost:9092',
+)
+
+greetings_topic = faust_app.topic('greetings', value_type=str)
+
+
+@faust_app.agent(greetings_topic)
+async def print_greetings(greetings):
+    async for greeting in greetings:
+        print(greeting)
+
+
+@faust_app.timer(5)
+async def produce():
+    for i in range(100):
+        await greetings_topic.send(value=f'hello {i}')
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    # Load the ML model
+    ml_models["answer_to_everything"] = fake_answer_to_everything_ml_model
+    await faust_app.start()
+    yield
+    # Clean up the ML models and release the resources
+    ml_models.clear()
+    await faust_app.stop()
+
+
+fastapi_app = FastAPI(lifespan=lifespan)
+
+
+@fastapi_app.get("/predict")
+async def predict(x: float):
+    result = ml_models["answer_to_everything"](x)
+    return {"result": result}
+
+if __name__ == '__main__':
+    faust_app.main()