Wisper::Sidekiq

Provides Wisper with asynchronous event publishing using Sidekiq.

Installation

Sidekiq 5+

gem 'wisper-sidekiq', '~> 1.0'

Sidekiq 4-

gem 'wisper-sidekiq', '~> 0.0'

Usage

publisher.subscribe(MyListener, async: true)

The listener must be a class (or module), not an object. This is because Sidekiq can not reconstruct the state of an object. However a class is easily reconstructed.

Additionally, you should also ensure that your methods used to handle events under MyListener are all declared as class methods:

class MyListener
  def self.event_name
  end
end

When publishing events the arguments must be simple as they need to be serialized. For example instead of sending an ActiveRecord model as an argument use its id instead.

See the Sidekiq best practices for more information.

YAML permitted classes

The gem internally uses YAML serialization/deserialization to pass your event data and subscribers to a sidekiq worker through redis.

By default, for security reasons, only a few basic classes like String or Array are permitted for deserialization.

If you are using custom types as your event data, you might run into

Psych::DisallowedClass:
   Tried to load unspecified class: MyEventData1

In that case, you can explicitly allow custom types using

Wisper::Sidekiq.configure do |config|
  config.register_safe_types(MyEventData1, MyEventData2)
end

Alternatively, you can opt-in for unsafe YAML loading that allows the deserialization of all classes using

Wisper::Sidekiq.configure do |config|
  config.use_unsafe_yaml!
end

Keep in mind that doing this can lead to RCE vulneraibility if an unauthorised actor gets the write access to your redis server.

Passing down sidekiq options

In order to define custom sidekiq_options you can add sidekiq_options class method in your subscriber definition - those options will be passed to Sidekiq's set method just before scheduling the asynchronous worker.

Passing down schedule options

In order be able to schedule jobs to be run in the future following Scheduled Jobs you can add sidekiq_schedule_options class method in your subscriber definition - those options will be passed to Sidekiq's perform_in method when the worker is called.

This feature is not as powerful as Sidekiq's API that allows you to set this on every job enqueue, in this case you're able to set this for the whole listener class like:

class MyListener
  #...

  def self.sidekiq_schedule_options
    { perform_in: 5 }
  end

  #...
end

Or you can set this per event (method called on the listener), like so:

class MyListener
  #...

  def self.sidekiq_schedule_options
    { event_name: { perform_in: 5 } }
  end

  def self.event_name
    #...
  end

  #...
end

In both cases the perform_at option is also available.

Compatibility

The same Ruby versions as Sidekiq are officially supported, but it should work with any 2.x syntax Ruby including JRuby and Rubinius.

See the build status for details.

Running Specs

scripts/sidekiq
bundle exec rspec

Contributing

To run sidekiq use scripts/sidekiq. This wraps sidekiq in rerun which will restart sidekiq when specs/dummy_app changes.