ActionCable - Failed to upgrade to WebSocket in production
<p>ActionCable doesn't work in production. Works well in development, but not in production.</p>

<p>Running Nginx with Puma on Ubuntu 14.04. I have checked that redis-server is up and running.</p>

<p>Rails -v 5.0.0.1</p>

<p><code>production.log</code>:</p>

<pre><code>INFO -- : Started GET "/cable/"[non-WebSocket] for 178.213.184.193 at 2016-11-25 14:55:39 +0100
ERROR -- : Failed to upgrade to WebSocket (REQUEST_METHOD: GET, HTTP_CONNECTION: close, HTTP_UPGRADE: )
INFO -- : Finished "/cable/"[non-WebSocket] for 178.213.184.193 at 2016-11-25 14:55:39 +0100
</code></pre>

<p>Request from client:</p>

<pre><code>GET ws://mityakoval.com/cable HTTP/1.1
Host: mityakoval.com
Connection: Upgrade
Pragma: no-cache
Cache-Control: no-cache
Upgrade: websocket
Origin: http://mityakoval.com
Sec-WebSocket-Version: 13
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36
Accept-Encoding: gzip, deflate, sdch
Accept-Language: ru-RU,ru;q=0.8,en-US;q=0.6,en;q=0.4,uk;q=0.2,nb;q=0.2
Cookie: _vaktdagboka_session=******
Sec-WebSocket-Key: *******
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits
Sec-WebSocket-Protocol: actioncable-v1-json, actioncable-unsupported
</code></pre>

<p>Response: </p>

<pre><code>HTTP/1.1 404 Not Found
Server: nginx/1.4.6 (Ubuntu)
Date: Fri, 25 Nov 2016 13:52:21 GMT
Content-Type: text/plain
Transfer-Encoding: chunked
Connection: keep-alive
Cache-Control: no-cache
X-Request-Id: d6374238-69ef-476e-8fc5-e2f8bbb663de
X-Runtime: 0.002500
</code></pre>

<p><code>nginx.conf</code>:</p>

<pre><code>upstream puma {
  server unix:///home/mityakoval/apps/vaktdagboka/shared/tmp/sockets/vaktdagboka-puma.sock;
}

server {
  listen 80 default_server deferred;
  # server_name example.com;

  root /home/mityakoval/apps/vaktdagboka/current/public;
  access_log /home/mityakoval/apps/vaktdagboka/current/log/nginx.access.log;
  error_log /home/mityakoval/apps/vaktdagboka/current/log/nginx.error.log info;

  location ^~ /assets/ {
    gzip_static on;
    expires max;
    add_header Cache-Control public;
  }

  try_files $uri/index.html $uri @puma;
  location @puma {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;

    proxy_pass http://puma;
  }

  location /cable {
    proxy_pass http://puma;
    proxy_http_version 1.1;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "Upgrade";
  }

  error_page 500 502 503 504 /500.html;
  client_max_body_size 10M;
  keepalive_timeout 10;
}
</code></pre>

<p><code>cable.yml</code>:</p>

<pre><code>redis: &amp;redis
  adapter: redis
  url: redis://127.0.0.1:6379

production: *redis

development:
  adapter: async

test:
  adapter: async
</code></pre>

<p>in <code>production.rb</code>:</p>

<pre><code>config.action_cable.allowed_request_origins = ["http://mityakoval.com"]
</code></pre>

<p>in <code>routes.rb</code>:</p>

<pre><code>mount ActionCable.server, at: '/cable'
</code></pre>

<p><strong>UPDATE:</strong></p>

<p>Don't forget to restart nginx :) That was the problem for me.</p>