Rails 5, action-cable, docker and nginx

Question

This question has been asked many times but I am not able to figure out problem even after trying all solutions.

I am getting

[a9736d85-6b19-425f-b9b0-50070ad6ca5f] Started GET "/api/v1/notifications/"[non-WebSocket] for 172.18.0.8 at 2017-10-16 18:30:31 +0000
[a9736d85-6b19-425f-b9b0-50070ad6ca5f] Failed to upgrade to WebSocket (REQUEST_METHOD: GET, HTTP_CONNECTION: close, HTTP_UPGRADE: )
[a9736d85-6b19-425f-b9b0-50070ad6ca5f] Finished "/api/v1/notifications/"[non-WebSocket] for 172.18.0.8 at 2017-10-16 18:30:31 +0000

In my development.rb I have

config.action_cable.allowed_request_origins = [ 'http://172.18.0.8:3000', 'http://0.0.0.0:3000', '0.0.0.0', '0.0.0.0:3000']

In nginx.config, I have

 location @rails {
    proxy_set_header  X-Real-IP  $remote_addr;
    proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto http;
    proxy_set_header Host $http_host;
    proxy_redirect off;
    proxy_pass http://unicorn;
  }

  location /cable {
    proxy_pass http://unicorn;
    proxy_http_version 1.1;
    proxy_set_header Upgrade websocket;
    proxy_set_header Connection Upgrade;

    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-Proto https;
    proxy_redirect off;
  }
}

cable.yml looks like

development:
  adapter: redis
  url: redis://localhost:6379/1

Please tell me why I am getting this error?

Thanks in advance.

Answer 1

I got it running (with Puma) using the following nginx.conf:

upstream app {
    server app:3000 fail_timeout=0;
}

server {
    listen 80;
    server_name localhost;

    root /usr/src/app/public;

    location / {
        proxy_pass http://app;
        proxy_set_header  Host $host;
        proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header  X-Forwarded-Proto $scheme;
        proxy_set_header  X-Forwarded-Port $server_port;
        proxy_set_header  X-Forwarded-Host $host;
    }

    location /cable {
        proxy_pass         http://app;
        proxy_http_version 1.1;
        proxy_set_header   Upgrade $http_upgrade;
        proxy_set_header   Connection "upgrade";
        proxy_set_header   Host $http_host;
        break;
    }

    error_page 500 502 503 504 /500.html;
    client_max_body_size 4G;
    keepalive_timeout 10;
}