Anycable Rails

AnyCable allows you to use any WebSocket server (written in any language) as a replacement for built-in Rails ActionCable server.

With AnyCable you can use channels, client-side JS, broadcasting - (almost) all that you can do with ActionCable.

You can even use ActionCable in development and not be afraid of compatibility issues.

Example Application

For usage outside Rails see AnyCable repository.

Requirements

• Ruby ~> 2.3;
• Rails ~> 5.0;
• Redis

How It Works?

Links

• GitPitch Slides

• RailsClub Moscow 2016 slides and video (RU)

Compatible WebSocket servers

• Anycable Go
• ErlyCable

Installation

Add Anycable to your application's Gemfile:

gem 'anycable-rails'

# or if you want to use built-in Action Cable server
# for test and development (which is possible and recommended)
gem 'anycable-rails', group: :production

NOTE: if you want to require anycable-rails manually (i.e. with require: false in your Gemfile) make sure that it's loaded prior to Rails.application.initialize! call (see config/environment.rb).

And then run:

rails generate anycable

to create executable.

Configuration

Add config/anycable.ymlif you want to override defaults (see below):

production:
  # gRPC server host
  rpc_host: "localhost:50051"
  # Redis URL (for broadcasting) 
  redis_url: "redis://localhost:6379/2"
  # Redis channel name
  redis_channel: "anycable"

Anycable uses anyway_config, thus it is also possible to set configuration variables through secrets.yml or environment vars.

Usage

Run Anycable RPC server:

RAILS_ENV=production ./bin/anycable

and also run AnyCable-compatible WebSocket server, e.g. anycable-go:

anycable-go --host=localhost --port=3334

Don't forget to set cable url in your environment:

# For development it's likely the localhost

# config/environments/development.rb
config.action_cable.url = "ws://localhost:3334/cable"

# For production it's likely to have a sub-domain and secure connection

# config/environments/production.rb
config.action_cable.url = "wss://ws.example.com/cable"

Logging

Anycable uses Rails.logger as Anycable.logger by default, thus Anycable debug mode (ANYCABLE_DEBUG=1) is not available, you should configure Rails logger instead, e.g.:

# in Rails configuration
if Anycable.config.debug
  config.logger = Logger.new(STDOUT)
  config.log_level = :debug
end

You can also turn on access logging (Started <request data> / Finished <request data>):

# in anycable.yml
production:
  access_logs_disabled: false

ActionCable Compatibility

This is the compatibility list for the AnyCable gem, not for AnyCable servers (which may not support some of the features yet).

Feature	Status
Connection Identifiers	+
Connection Request (cookies, params)	+
Disconnect Handling	+
Subscribe to channels	+
Parameterized subscriptions	+
Unsubscribe from channels	+
Subscription Instance Variables	-
Performing Channel Actions	+
Streaming	+
Custom stream callbacks	-
Broadcasting	+
Periodical Timers	-
Disconnect remote clients	-

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/anycable/anycable-rails.

License

The gem is available as open source under the terms of the MIT License.