This example of aiohttp server in a thread fails with an RuntimeError: There is no current event loop in thread \'Thread-1\'.
error:
import thre
There's a new API intended for this use case:
https://docs.aiohttp.org/en/stable/web_advanced.html#application-runners
from aiohttp import web
import asyncio
async def healthz(request):
return web.Response(text="OK")
app = web.Application()
app.add_routes([web.get("/", healthz)])
async def runner():
runner = web.AppRunner(app)
await runner.setup()
site = web.TCPSite(runner, "localhost", 8080)
await site.start()
loop = asyncio.get_event_loop()
loop.run_until_complete(runner())
It's possible to use web.run_app
, just create a new event loop (and set handle_signals=False
to avoid RuntimeError: set_wakeup_fd only works in main thread
):
import threading
import asyncio
from aiohttp import web
def aiohttp_server():
def say_hello(request):
return web.Response(text='Hello, world')
asyncio.set_event_loop(asyncio.new_event_loop()) # create a new event loop here
app = web.Application(debug=True)
app.add_routes([web.get('/', say_hello)])
web.run_app(app, handle_signals=False)
Create handler
in main thread and manually create an event loop in child thread.
import asyncio
import threading
from aiohttp import web
def aiohttp_server():
def say_hello(request):
return web.Response(text='Hello, world')
app = web.Application(debug=True)
app.add_routes([web.get('/', say_hello)])
handler = app.make_handler()
return handler
def run_server(handler):
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
server = loop.create_server(handler, host='127.0.0.1', port=8089)
loop.run_until_complete(server)
loop.run_forever()
t = threading.Thread(target=run_server, args=(aiohttp_server(),))
t.start()
For new aiohttp
, use the following, thank @Auyer for notification.
import asyncio
import threading
from aiohttp import web
def aiohttp_server():
def say_hello(request):
return web.Response(text='Hello, world')
app = web.Application()
app.add_routes([web.get('/', say_hello)])
runner = web.AppRunner(app)
return runner
def run_server(runner):
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
loop.run_until_complete(runner.setup())
site = web.TCPSite(runner, 'localhost', 8080)
loop.run_until_complete(site.start())
loop.run_forever()
t = threading.Thread(target=run_server, args=(aiohttp_server(),))
t.start()
We must use app.make_handler
handler in main thread, example:
import asyncio
import threading
from aiohttp import web
loop = asyncio.get_event_loop()
def say_hello(request):
return web.Response(text='Hello, world')
app = web.Application(debug=True)
app.add_routes([web.get('/', say_hello)])
handler = app.make_handler()
server = loop.create_server(handler, host='127.0.0.1', port=8080)
def aiohttp_server():
loop.run_until_complete(server)
loop.run_forever()
t = threading.Thread(target=aiohttp_server)
t.start()