channels/consumer.py: encoding with 'idna' codec failed (UnicodeError: label empty or too long)

Cloned https://github.com/andrewgodwin/channels-examples/tree/master/multichat, ran successfully on local, but failed on Heroku, ERROR is "encoding with ‘idna’ codec failed "

From the error pint out, I suspect that channels may have issue to handle very LONG DATABASE_URL, because the DATABASE_URL in Heroku is very LONG, like: postgres://abcdefgijjldfadslfas:1234567890123456[e-mail]:5432/abcdefg12344567 Running successfully in local because local DATABASE_URL is SHORT, like postgresql://postgres@postgres/postgres

• Your OS and runtime environment, and browser if applicable Heroku, py3.6

• The versions of Channels, Daphne, Django, Twisted, and your ASGI backend (channels_redis normally)

aioredis==1.0.0
arrow==0.12.1
asgiref==2.2.0
async-timeout==2.0.1
attrs==17.4.0
autobahn==18.3.1
Automat==0.6.0
binaryornot==0.4.4
certifi==2018.1.18
channels==2.0.2
channels-redis==2.1.1
chardet==3.0.4
click==6.7
constantly==15.1.0
cookiecutter==1.6.0
daphne==2.1.0
dj-database-url==0.5.0
Django==2.0.4
django-environ==0.4.4
django-heroku==0.3.1
future==0.16.0
hiredis==0.2.0
hyperlink==18.0.0
idna==2.6
incremental==17.5.0
Jinja2==2.10
jinja2-time==0.2.0
MarkupSafe==1.0
msgpack==0.5.6
poyo==0.4.1
psycopg2==2.7.4
python-dateutil==2.7.0
pytz==2018.3
requests==2.18.4
six==1.11.0
Twisted==17.9.0
txaio==2.9.0
urllib3==1.22
whichcraft==0.4.1
whitenoise==3.3.1
zope.interface==4.4.3

• What you expected to happen vs. what actually happened Depoly on Heroku should working as local

• How you’re running Channels (runserver? daphne/runworker? Nginx/Apache in front?) Procfile: web: daphne -b 0.0.0.0 -p $PORT multichat.asgi:application

• Console logs and full tracebacks of any errors

2018-04-05T10:51:09.963017+00:00 app[web.1]: [2018/04/05 10:51:09] WebSocket DISCONNECT /chat/stream/ [10.148.31.26:12204]
2018-04-05T10:51:09.963413+00:00 heroku[router]: at=info method=GET path="/chat/stream/" host=dj-.herokuapp.com request_id=24997cac-1ae3-4182-95fb-9fc160fcdbae fwd="23.105.202.100" dyno=web.1 connect=0ms service=1050ms status=101 bytes=145 protocol=https
2018-04-05T10:51:11.911270+00:00 app[web.1]: [2018/04/05 10:51:11] WebSocket HANDSHAKING /chat/stream/ [10.33.239.90:28093]
2018-04-05T10:51:11.921067+00:00 app[web.1]: [2018/04/05 10:51:11] WebSocket CONNECT /chat/stream/ [10.33.239.90:28093]
2018-04-05T10:51:12.737859+00:00 app[web.1]: 2018-04-05 10:51:12,737 - ERROR - server - Exception inside application: encoding with 'idna' codec failed (UnicodeError: label empty or too long)
2018-04-05T10:51:12.737872+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/channels/consumer.py", line 54, in __call__
2018-04-05T10:51:12.737875+00:00 app[web.1]:     await await_many_dispatch([receive, self.channel_receive], self.dispatch)
2018-04-05T10:51:12.737876+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/channels/utils.py", line 47, in await_many_dispatch
2018-04-05T10:51:12.737878+00:00 app[web.1]:     result = task.result()
2018-04-05T10:51:12.737880+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/channels_redis/core.py", line 185, in receive
2018-04-05T10:51:12.737882+00:00 app[web.1]:     self.receive_loop_task.result()
2018-04-05T10:51:12.737884+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/channels_redis/core.py", line 204, in receive_loop
2018-04-05T10:51:12.737885+00:00 app[web.1]:     real_channel, message = await self.receive_single(general_channel)
2018-04-05T10:51:12.737887+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/channels_redis/core.py", line 220, in receive_single
2018-04-05T10:51:12.737889+00:00 app[web.1]:     async with self.connection(index) as connection:
2018-04-05T10:51:12.737890+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/channels_redis/core.py", line 399, in __aenter__
2018-04-05T10:51:12.737892+00:00 app[web.1]:     self.conn = await aioredis.create_redis(**self.kwargs)
2018-04-05T10:51:12.737893+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/aioredis/commands/__init__.py", line 174, in create_redis
2018-04-05T10:51:12.737895+00:00 app[web.1]:     loop=loop)
2018-04-05T10:51:12.737897+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/aioredis/connection.py", line 107, in create_connection
2018-04-05T10:51:12.737899+00:00 app[web.1]:     timeout, loop=loop)
2018-04-05T10:51:12.737900+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/asyncio/tasks.py", line 333, in wait_for
2018-04-05T10:51:12.737902+00:00 app[web.1]:     return (yield from fut)
2018-04-05T10:51:12.737903+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/aioredis/stream.py", line 19, in open_connection
2018-04-05T10:51:12.737905+00:00 app[web.1]:     lambda: protocol, host, port, **kwds)
2018-04-05T10:51:12.737907+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/asyncio/base_events.py", line 732, in create_connection
2018-04-05T10:51:12.737908+00:00 app[web.1]:     infos = f1.result()
2018-04-05T10:51:12.737910+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/concurrent/futures/thread.py", line 55, in run
2018-04-05T10:51:12.737911+00:00 app[web.1]:     result = self.fn(*self.args, **self.kwargs)
2018-04-05T10:51:12.737913+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/socket.py", line 743, in getaddrinfo
2018-04-05T10:51:12.737915+00:00 app[web.1]:     for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
2018-04-05T10:51:12.737922+00:00 app[web.1]:   encoding with 'idna' codec failed (UnicodeError: label empty or too long)

[kevinqqnj]

Thanks @andrewgodwin & @matthiask ! You’re right, REDIS URL is wrong in my settings.py.

Sorry, I blindly followed the tutorial of Channels. Actually if deploying to VPS (e.g. Heroku) other than localhost, should update CHANNEL_LAYERS from Tuple to String, to include username and password:

# settings.py
CHANNEL_LAYERS = {
    "default": {
        "BACKEND": "channels_redis.core.RedisChannelLayer",
        "CONFIG": {
            # in tutorial it says: "hosts": [('127.0.0.1', 6379)],
            "hosts": [os.environ.get('REDIS_URL', 'redis://redis:6379')],
        },
    },
}

Now it’s working.

[iMerica]

Opened https://github.com/django/channels/issues/1054