make Sanic.create_server return an asyncio.Server

docs/index.rst

@@ -33,6 +33,7 @@ Guides
    sanic/changelog
    sanic/contributing
    sanic/api_reference
+   sanic/asyncio_python37
 
 
 Module Documentation

docs/sanic/asyncio_python37.rst

@@ -0,0 +1,58 @@
+Python 3.7 AsyncIO examples
+###########################
+
+With Python 3.7 AsyncIO got major update for the following types:
+
+ - asyncio.AbstractEventLoop
+ - asyncio.AnstractServer
+
+
+This example shows how to use sanic with Python 3.7, to be precise: how to retrieve an asyncio server instance:
+
+.. code:: python
+
+    import asyncio
+    import socket
+    import os
+
+    from sanic import Sanic
+    from sanic.response import json
+
+    app = Sanic(__name__)
+
+
+    @app.route("/")
+    async def test(request):
+        return json({"hello": "world"})
+
+
+    server_socket = '/tmp/sanic.sock'
+
+    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+
+    try:
+        os.remote(server_socket)
+    finally:
+        sock.bind(server_socket)
+
+    if __name__ == "__main__":
+        loop = asyncio.get_event_loop()
+        srv_coro = app.create_server(
+            sock=sock,
+            return_asyncio_server=True,
+            asyncio_server_args=dict(
+                start_serving=False
+            )
+        )
+        srv = loop.run_until_complete(srv_coro)
+        try:
+            assert srv.is_serving() is False
+            loop.run_until_complete(srv.start_serving())
+            assert srv.is_serving() is True
+            loop.run_until_complete(srv.serve_forever())
+        except KeyboardInterrupt:
+            srv.close()
+            loop.close()
+
+
+Please note that uvloop does not support these features yet.

sanic/app.py

@@ -1121,6 +1121,8 @@ async def create_server(
         backlog: int = 100,
         stop_event: Any = None,
         access_log: Optional[bool] = None,
+        return_asyncio_server=False,
+        asyncio_server_kwargs=None,
     ) -> None:
         """
         Asynchronous version of :func:`run`.
@@ -1154,6 +1156,13 @@ async def create_server(
         :type stop_event: None
         :param access_log: Enables writing access logs (slows server)
         :type access_log: bool
+        :param return_asyncio_server: flag that defines whether there's a need
+                                      to return asyncio.Server or
+                                      start it serving right away
+        :type return_asyncio_server: bool
+        :param asyncio_server_kwargs: key-value arguments for
+                                      asyncio/uvloop create_server method
+        :type asyncio_server_kwargs: dict
         :return: Nothing
         """
 
@@ -1184,7 +1193,7 @@ async def create_server(
             loop=get_event_loop(),
             protocol=protocol,
             backlog=backlog,
-            run_async=True,
+            run_async=return_asyncio_server,
         )
 
         # Trigger before_start events
@@ -1193,7 +1202,9 @@ async def create_server(
             server_settings.get("loop"),
         )
 
-        return await serve(**server_settings)
+        return await serve(
+            asyncio_server_kwargs=asyncio_server_kwargs, **server_settings
+        )
 
     async def trigger_events(self, events, loop):
         """Trigger events (functions or async)

sanic/server.py

@@ -656,6 +656,7 @@ def serve(
     websocket_write_limit=2 ** 16,
     state=None,
     graceful_shutdown_timeout=15.0,
+    asyncio_server_kwargs=None,
 ):
     """Start asynchronous HTTP Server on an individual process.
 
@@ -700,6 +701,8 @@ def serve(
     :param router: Router object
     :param graceful_shutdown_timeout: How long take to Force close non-idle
                                       connection
+    :param asyncio_server_kwargs: key-value args for asyncio/uvloop
+                                  create_server method
     :return: Nothing
     """
     if not run_async:
@@ -734,7 +737,9 @@ def serve(
         state=state,
         debug=debug,
     )
-
+    asyncio_server_kwargs = (
+        asyncio_server_kwargs if asyncio_server_kwargs else {}
+    )
     server_coroutine = loop.create_server(
         server,
         host,
@@ -743,6 +748,7 @@ def serve(
         reuse_port=reuse_port,
         sock=sock,
         backlog=backlog,
+        **asyncio_server_kwargs
     )
 
     # Instead of pulling time at the end of every request,

tests/test_app.py

@@ -1,12 +1,22 @@
 import asyncio
 import logging
+import sys
 
+from inspect import isawaitable
 import pytest
 
 from sanic.exceptions import SanicException
 from sanic.response import text
 
 
+def uvloop_installed():
+    try:
+        import uvloop
+        return True
+    except ImportError:
+        return False
+
+
 def test_app_loop_running(app):
     @app.get("/test")
     async def handler(request):
@@ -17,6 +27,32 @@ async def handler(request):
     assert response.text == "pass"
 
 
+@pytest.mark.skipif(sys.version_info < (3, 7),
+                    reason="requires python3.7 or higher")
+def test_create_asyncio_server(app):
+    if not uvloop_installed():
+        loop = asyncio.get_event_loop()
+        asyncio_srv_coro = app.create_server(
+            return_asyncio_server=True)
+        assert isawaitable(asyncio_srv_coro)
+        srv = loop.run_until_complete(asyncio_srv_coro)
+        assert srv.is_serving() is True
+
+
+@pytest.mark.skipif(sys.version_info < (3, 7),
+                    reason="requires python3.7 or higher")
+def test_asyncio_server_start_serving(app):
+    if not uvloop_installed():
+        loop = asyncio.get_event_loop()
+        asyncio_srv_coro = app.create_server(
+            return_asyncio_server=True,
+            asyncio_server_kwargs=dict(
+                start_serving=False
+            ))
+        srv = loop.run_until_complete(asyncio_srv_coro)
+        assert srv.is_serving() is False
+
+
 def test_app_loop_not_running(app):
     with pytest.raises(SanicException) as excinfo:
         app.loop

tests/test_config.py

@@ -231,10 +231,12 @@ async def test_config_access_log_passing_in_create_server(app):
     async def _request(sanic, loop):
         app.stop()
 
-    await app.create_server(port=1341, access_log=False)
+    await app.create_server(port=1341, access_log=False,
+                            return_asyncio_server=True)
     assert app.config.ACCESS_LOG == False
 
-    await app.create_server(port=1342, access_log=True)
+    await app.create_server(port=1342, access_log=True,
+                            return_asyncio_server=True)
     assert app.config.ACCESS_LOG == True
 
 

tests/test_keep_alive_timeout.py

@@ -51,7 +51,9 @@ def _sanic_endpoint_test(
         uri="/",
         gather_request=True,
         debug=False,
-        server_kwargs={},
+        server_kwargs={
+            "return_asyncio_server": True,
+        },
         *request_args,
         **request_kwargs
     ):

tests/test_logo.py

@@ -12,7 +12,8 @@
 
 
 def test_logo_base(app, caplog):
-    server = app.create_server(debug=True)
+    server = app.create_server(
+        debug=True, return_asyncio_server=True)
     loop = asyncio.new_event_loop()
     asyncio.set_event_loop(loop)
     loop._stopping = False
@@ -31,7 +32,8 @@ def test_logo_base(app, caplog):
 def test_logo_false(app, caplog):
     app.config.LOGO = False
 
-    server = app.create_server(debug=True)
+    server = app.create_server(
+        debug=True, return_asyncio_server=True)
     loop = asyncio.new_event_loop()
     asyncio.set_event_loop(loop)
     loop._stopping = False
@@ -50,7 +52,8 @@ def test_logo_false(app, caplog):
 def test_logo_true(app, caplog):
     app.config.LOGO = True
 
-    server = app.create_server(debug=True)
+    server = app.create_server(
+        debug=True, return_asyncio_server=True)
     loop = asyncio.new_event_loop()
     asyncio.set_event_loop(loop)
     loop._stopping = False
@@ -69,7 +72,8 @@ def test_logo_true(app, caplog):
 def test_logo_custom(app, caplog):
     app.config.LOGO = "My Custom Logo"
 
-    server = app.create_server(debug=True)
+    server = app.create_server(
+        debug=True, return_asyncio_server=True)
     loop = asyncio.new_event_loop()
     asyncio.set_event_loop(loop)
     loop._stopping = False

tests/test_server_events.py

@@ -83,7 +83,8 @@ class MySanicDb:
     async def init_db(app, loop):
         app.db = MySanicDb()
 
-    await app.create_server()
+    await app.create_server(
+        debug=True, return_asyncio_server=True)
 
     assert hasattr(app, "db")
     assert isinstance(app.db, MySanicDb)