Background Worker

Provides a worker abstraction with an additional status channel.

Start by making a worker class which extends from BackgroundWorker::Base

    class MyWorker < BackgroundWorker::Base
      def perform(options={})
        report_progress('Starting')
        if options[:message].blank?
          report_failed("No message provided")
          return
        end

        puts options[:message]
        {original_message: message}
      end
    end

Then, when you want to perform a task in the background, use klass#perform_in_background which exists in Base:

    worker_id = MyWorker.perform_later(message: "hello!")

Backgrounded

By default this will call your instance method in the foreground -- you have to provide an #enqueue_with configuration like so:

    BackgroundWorker.configure(
      enqueue_with: -> klass, options {
        Resque.enqueue(klass, options)
      }
    )

This is independent of the status reporting which (currently) always uses Redis.

Getting the status

The worker_id you are returned can be used to get the status and whether the worker has finished successfully, failed, or is still in progress:

    state = BackgroundWorker.get_state_of(worker_id)

The state is represented by a hash with the following keys:

key	description
message	Reported message
detailed_message	Detailed version of above when provided
status	:successful, :failed, or null if still processing
completed	True if report_failed, report_successful called (or worker
finished without exception -- which calls report_successful)
data	Arbitrary data returned by worker method on success or report_failed

If an exception is raised, the worker will call #report_failed with the details. You can provide a callback with #after_exception in the config.

Installation

Add to your Gemfile:

    gem 'background_worker'

Release

To publish a new version of this gem the following steps must be taken.

• Update the version in the following files

    CHANGELOG.md
    lib/background_worker/version.rb
  

• Create a tag using the format v0.1.0
• Follow build progress in GitHub actions