Websocket error using Django Channels with EC2 - django

Question

I'm trying to build an app in Django that uses Django Channels. I'm deploying on Elastic Beanstalk. My understanding is that the application load balancer supports websockets and I can route websocket traffic to the appropriate port. The websockets work on my localhost:8000. I'm using the free tier Redis Labs for my channel layer.
I followed this tutorial.
https://blog.mangoforbreakfast.com/2017/02/13/django-channels-on-aws-elastic-beanstalk-using-an-alb/#comment-43
Following this tutorial it appears I can get Daphne and the workers running on the correct ports. I SSHed into the EC2 instance to get the following output.
$ sudo /usr/local/bin/supervisorctl -c /opt/python/etc/supervisord.conf status
Daphne RUNNING pid 4240, uptime 0:05:51
Worker:Worker_00 RUNNING pid 4242, uptime 0:05:51
Worker:Worker_01 RUNNING pid 4243, uptime 0:05:51
Worker:Worker_02 RUNNING pid 4244, uptime 0:05:51
Worker:Worker_03 RUNNING pid 4245, uptime 0:05:51
httpd RUNNING pid 4248, uptime 0:05:51
My daphne.out.log and workers.out.log look fine.
$ cat daphne.out.log
2017-07-20 21:41:43,693 INFO Starting server at tcp:port=5000:interface=0.0.0.0, channel layer mysite.asgi:channel_layer.
2017-07-20 21:41:43,693 INFO HTTP/2 support not enabled (install the http2 and tls Twisted extras)
2017-07-20 21:41:43,694 INFO Using busy-loop synchronous mode on channel layer
2017-07-20 21:41:43,694 INFO Listening on endpoint tcp:port=5000:interface=0.0.0.0
$ cat workers.out.log
2017-07-20 21:41:44,114 - INFO - runworker - Using single-threaded worker.
2017-07-20 21:41:44,120 - INFO - runworker - Using single-threaded worker.
2017-07-20 21:41:44,121 - INFO - runworker - Running worker against channel layer default (asgi_redis.core.RedisChannelLayer)
2017-07-20 21:41:44,121 - INFO - worker - Listening on channels http.request, websocket.connect, websocket.disconnect, websocket.receive
2017-07-20 21:41:44,126 - INFO - runworker - Using single-threaded worker.
2017-07-20 21:41:44,126 - INFO - runworker - Running worker against channel layer default (asgi_redis.core.RedisChannelLayer)
2017-07-20 21:41:44,126 - INFO - runworker - Running worker against channel layer default (asgi_redis.core.RedisChannelLayer)
2017-07-20 21:41:44,127 - INFO - worker - Listening on channels http.request, websocket.connect, websocket.disconnect, websocket.receive
2017-07-20 21:41:44,127 - INFO - worker - Listening on channels http.request, websocket.connect, websocket.disconnect, websocket.receive
2017-07-20 21:41:44,133 - INFO - runworker - Using single-threaded worker.
2017-07-20 21:41:44,136 - INFO - runworker - Running worker against channel layer default (asgi_redis.core.RedisChannelLayer)
2017-07-20 21:41:44,136 - INFO - worker - Listening on channels http.request, websocket.connect, websocket.disconnect, websocket.receive
From here I updated the security group settings and configured the load balancer and tested my webpage. Instead of /ws/ as the path for rerouting, I used /table/* because those are the pages that need websockets.
If I use /ws/ I get this error.
WebSocket connection to 'ws://example.com/table/1/' failed: Error during WebSocket handshake: Unexpected response code: 404
If I use /table/* I get this error.
WebSocket connection to 'ws://example.com/table/1/' failed: Error during WebSocket handshake: Unexpected response code: 504
When I changed the security group settings of my load balancer to also allow TCP at port 5000, the worker log changes. With the /ws/ path rule in my load balancer, I now get this in the worker log:
...
2017-07-20 21:41:44,136 - INFO - worker - Listening on channels http.request, websocket.connect, websocket.disconnect, websocket.receive
Not Found: /ws/
Not Found: /ws/
Not Found: /ws/
Not Found: /ws/
Not Found: /ws/
Not Found: /ws/
If I use the /table/* path, I get a very long error in my log.
2017-07-21 01:22:05,270 - ERROR - worker - Error processing message with consumer deal.consumers.ws_connect:
Traceback (most recent call last):
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/contrib/sessions/backends/base.py", line 193, in _get_session
return self._session_cache
AttributeError: 'SessionStore' object has no attribute '_session_cache'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 199, in ensure_connection
self.connect()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 171, in connect
self.connection = self.get_new_connection(conn_params)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/postgresql/base.py", line 175, in get_new_connection
connection = Database.connect(**conn_params)
File "/opt/python/run/venv/local/lib64/python3.4/site-packages/psycopg2/__init__.py", line 130, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/opt/python/run/venv/local/lib/python3.4/site-packages/channels/worker.py", line 119, in run
consumer(message, **kwargs)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/channels/sessions.py", line 220, in inner
result = func(message, *args, **kwargs)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/channels/auth.py", line 71, in inner
message.user = auth.get_user(fake_request)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/contrib/auth/__init__.py", line 167, in get_user
user_id = _get_user_session_key(request)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/contrib/auth/__init__.py", line 59, in _get_user_session_key
return get_user_model()._meta.pk.to_python(request.session[SESSION_KEY])
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/contrib/sessions/backends/base.py", line 48, in __getitem__
return self._session[key]
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/contrib/sessions/backends/base.py", line 198, in _get_session
self._session_cache = self.load()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/contrib/sessions/backends/db.py", line 33, in load
expire_date__gt=timezone.now()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/models/manager.py", line 122, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/models/query.py", line 381, in get
num = len(clone)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/models/query.py", line 240, in __len__
self._fetch_all()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/models/query.py", line 1074, in _fetch_all
self._result_cache = list(self.iterator())
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/models/query.py", line 52, in __iter__
results = compiler.execute_sql()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/models/sql/compiler.py", line 846, in execute_sql
cursor = self.connection.cursor()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 231, in cursor
cursor = self.make_debug_cursor(self._cursor())
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 204, in _cursor
self.ensure_connection()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 199, in ensure_connection
self.connect()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/utils.py", line 95, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 199, in ensure_connection
self.connect()
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/base/base.py", line 171, in connect
self.connection = self.get_new_connection(conn_params)
File "/opt/python/run/venv/local/lib/python3.4/site-packages/django/db/backends/postgresql/base.py", line 175, in get_new_connection
connection = Database.connect(**conn_params)
File "/opt/python/run/venv/local/lib64/python3.4/site-packages/psycopg2/__init__.py", line 130, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
django.db.utils.OperationalError: could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
Unsurprisingly when I try to use the websockets I get this error:
WebSocket is already in CLOSING or CLOSED state.
Any idea what I'm doing wrong?

Answer 1

Ok so problem was when Daphne runs it doesn't see the environment variables. I added the following code to my supervisord.conf file and it worked:
[program:Daphne]
environment=PATH="/opt/python/run/venv/bin"
**command=/bin/bash -c "source /opt/python/current/env && /opt/python/run/venv/bin/daphne -b 0.0.0.0 -p 5000 mysite.asgi:channel_layer"**
directory=/opt/python/current/app
autostart=true
autorestart=true
redirect_stderr=true
stdout_logfile=/tmp/daphne.out.log
[program:Worker]
environment=PATH="/opt/python/run/venv/bin"
**command=/bin/bash -c "source /opt/python/current/env && python manage.py runworker"**
directory=/opt/python/current/app
process_name=%(program_name)s_%(process_num)02d
numprocs=4
autostart=true
autorestart=true
redirect_stderr=true
stdout_logfile=/tmp/workers.out.log