[serve] Fix nonblocking serve.init() (#8068)

python/ray/serve/BUILD

@@ -13,7 +13,7 @@ py_library(
 py_test(
     name = "test_serve",
     size = "medium",
-    srcs = glob(["tests/*.py"]),
+    srcs = glob(["tests/*.py"], exclude=["tests/test_nonblocking.py"]),
     tags = ["exclusive"],
     deps = [":serve_lib"],
 )
@@ -26,6 +26,14 @@ py_test(
     deps = [":serve_lib"]
 )
 
+py_test(
+    name = "test_nonblocking",
+    size = "small",
+    srcs = glob(["tests/test_nonblocking.py"]),
+    tags = ["exclusive"],
+    deps = [":serve_lib"],
+)
+
 # Make sure the example showing in doc is tested
 py_test(
     name = "quickstart_class",
@@ -41,4 +49,4 @@ py_test(
     srcs = glob(["examples/doc/*.py"]),
     tags = ["exclusive"],
     deps = [":serve_lib"]
-)
+)

python/ray/serve/http_proxy.py

@@ -26,11 +26,11 @@ class HTTPProxy:
     # blocks forever
     """
 
-    def __init__(self):
+    async def fetch_config_from_master(self):
         assert ray.is_initialized()
         master = ray.util.get_actor(SERVE_MASTER_NAME)
-        self.route_table, [self.router_handle] = ray.get(
-            master.get_http_proxy_config.remote())
+        self.route_table, [self.router_handle
+                           ] = await master.get_http_proxy_config.remote()
 
     def set_route_table(self, route_table):
         self.route_table = route_table
@@ -163,8 +163,9 @@ class HTTPProxy:
 
 @ray.remote
 class HTTPProxyActor:
-    def __init__(self, host, port):
+    async def __init__(self, host, port):
         self.app = HTTPProxy()
+        await self.app.fetch_config_from_master()
         self.host = host
         self.port = port
 

python/ray/serve/tests/test_nonblocking.py

@@ -0,0 +1,23 @@
+import requests
+import sys
+
+from ray import serve
+
+
+def test_nonblocking():
+    serve.init()
+    serve.create_endpoint("endpoint", "/api")
+
+    def function(flask_request):
+        return {"method": flask_request.method}
+
+    serve.create_backend(function, "echo:v1")
+    serve.set_traffic("endpoint", {"echo:v1": 1.0})
+
+    resp = requests.get("http://127.0.0.1:8000/api").json()["method"]
+    assert resp == "GET"
+
+
+if __name__ == "__main__":
+    import pytest
+    sys.exit(pytest.main(["-v", __file__]))