Connecting ActionCable to different host - ruby-on-rails

Question

I'm running a rails 5 app as a backend server, and an ember application for a front-end application. They are two separate applications hosted on two different domains - say, backend.dev and frontend.dev
The rails application has a simple connection class found at app/channels/application_cable/connection.rb that looks like the following:
module ApplicationCable
class Connection < ActionCable::Connection::Base
def connect
Rails.logger.debug("env: #{env.inspect}")
Rails.logger.info("cookies.signed: #{cookies.signed.inspect}")
end
end
end
I have a simple base channel class at app/channels/application_cable/channel.rb with the following:
module ApplicationCable
class Channel < ActionCable::Channel::Base
end
end
And a single implementation of that class at app/channels/events_channel.rb:
class EventsChannel < ApplicationCable::Channel
def subscribed
Rails.logger.debug("env: #{env.inspect}")
Rails.logger.info("cookies.signed: #{cookies.signed.inspect}")
stream_from 'events'
end
end
On the ember side of things, I'm using the ember-cable package. I've setup my consumer in my frontend by extending the controller class with the following:
cableService: Ember.inject.service('cable'),
setupConsumer: Ember.on('init', function() {
let service = this.get('cableService');
let consumer = service.createConsumer(`ws://backend.dev`);
let channel = 'EventsChannel';
consumer.subscriptions.create(channel, {
disconnected() {
Ember.debug(`${channel}#disconnected`);
},
connected() {
Ember.debug(`${channel}#connected`);
},
I'm fairly sure that my consumer is setup correctly, as I'm seeing some debug output when I get the following output to my js console:
DEBUG: EventsChannel#disconnected
However, I'm also seeing an odd error in the console as well:
WebSocket connection to 'ws://backend.dev/' failed: Error during WebSocket handshake: Unexpected response code: 200
I'm not sure what to make of the response code error here, and there's absolutely nothing being logged in my rails app. Is there anything additional that I need to setup to have actioncable work across domains? Any idea of what the 200 response code means here?

Answer 1

Try this:
# routes.rb
Rails.application.routes.draw do
# your code
mount ActionCable.server => '/cable'
end
Then in your app:
let consumer = service.createConsumer(`ws://backend.dev/cable`);
If you face handshake problems, there are few solutions:
Check if your frontend app is compatible with protocol 07 or newer.
Check if your website is in config.action_cable.allowed_request_origins
Add config.web_socket_server_url = 'ws://backend.dev/cable' to your ENV cofig file.
You can use a fast "dirty" hack. Just add following to your ENV cofig file:
config.action_cable.disable_request_forgery_protection = true