In development mode things seemed to take care of themselves. Production mode was a different matter. Let’s just say it was a sensitive and delicate configuration. So in documenting this I’ve tried to condense things to the bare minimum and using the simplest configuration: hosting the “cable” within the host application (i.e. in the same virtual host). For full ActionCable documentation please visit: Rails Guides
Make sure you have a cable.js file (app/assets/javascripts/cable.js)
The “rails new” command should have created this for you.
Create a handler (app/assets/javascripts/channels/chat_channel.coffee)
App.chat = App.cable.subscriptions.create "ChatChannel",
connected: ->
alert 'connected'
disconnected: ->
alert 'disconnected'
received: (data) ->
# do you screen update stuff here
I’ve included popup alerts. These are quite useful when you’re doing this for the first time so you know your basic connection is working.
Make sure you have your channel and connection ActionCable files
Check for app/channels/application_cable/channel.rb and app/channels/application_cable/connection.rb. These should have been created for you. If you’re running ActionCable within your application (rather than on a separate server/vhost) you can add authentication for the connection thus:
module ApplicationCable
class Connection < ActionCable::Connection::Base
identified_by :current_user
def connect
self.current_user = find_verified_user
end
protected
def find_verified_user
if current_user = User.find_by(id: cookies.signed[:user_id])
current_user
else
reject_unauthorized_connection
end
end
end
end
Create your own channel file (app/channels/chat_channel.rb)
Here’s where you subscribe to your own broadcast.
class ChatChannel < ApplicationCable::Channel
def subscribed
stream_from 'chat_channel'
end
def unsubscribed
# Any cleanup needed when channel is unsubscribed
end
end
Set your configuration parameters
There are 2 files to change. First we must update config/environments/production.rb and set the config.action_cable constants:
config.action_cable.url = 'ws://myapp.spannersoftware.com/cable' # ws:// is non-secure, wss:// is secure config.action_cable.allowed_request_origins = [ 'http://myapp.spannersoftware.com' ]
Important: do not add a trailing slash to either of these!
Next update config/cable.yml and set the host and port for the redis server:
development: adapter: async test: adapter: async production: adapter: redis url: redis://localhost:6379/1
You may not need to change this.
Add the ActionCable metatag
In app/views/layouts/application.html.erb add the following line in the <head> section:
<%= action_cable_meta_tag %>
Install and fire up the Redis server
Redis is a cool bit of kit for providing efficient messaging, for more information go here: Redis.io.
apt-get install redis-server service redis-server start
Edit /etc/redis/redis.conf to set the port to 6379 and bind to 127.0.0.1.
Configure Nginx and Puma
Here is my Nginx virtual host example:
upstream my_app {
server unix:/home/myapp/tmp/myapp.sock;
}
server {
listen 10.10.10.10:80;
server_name myapp.spannersoftware.com;
access_log /home/myapp/log/access.log;
error_log /home/myapp/log/error.log;
root /home/myapp/public;
location / {
try_files /maint.html $uri @ruby;
}
location @ruby {
proxy_pass http://my_app;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
}
location /cable {
proxy_pass http://my_app;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
}
}
Here is my Puma config (config/puma.rb):
threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }.to_i
threads threads_count, threads_count
bind "unix:/home/myapp/tmp/bluebird2.sock"
environment ENV.fetch("RAILS_ENV") { "production" }
workers ENV.fetch("WEB_CONCURRENCY") { 2 }
daemonize true
pidfile '/home/myapp/tmp/pids/puma.pid'
I'm using a Unix socket here, the default environment is production, the process is daemonized and I've specified a pidfile location. The rest of the settings are default.
Set your app running
Assuming you have the puma gem installed correctly you should be able to run your application complete with working ActionCable.
cd /home/myapp puma -C config/puma.rb -e production
You should see the message “connected” pop up in your browser when you first load the page. Hopefully you’ve found this helpful but please let me know if I’ve missed anything.