Google Cloud Pub/Sub adapter and worker for ActiveJob

gem 'activejob-google_cloud_pubsub'

First, change the ActiveJob backend.

Rails.application.config.active_job.queue_adapter = :google_cloud_pubsub

Write the Job class and code to use it.

class HelloJob < ApplicationJob
  def perform(name)
    puts "hello, #{name}!"
  end
end

class HelloController < ApplicationController
  def say
    HelloJob.perform_later params[:name]
  end
end

In order to test the worker in your local environment, it is a good idea to use the Pub/Sub emulator provided by gcloud command. Refer to this document for the installation procedure.

When the installation is completed, execute the following command to start up the worker.

$ gcloud beta emulators pubsub start

(Switch to another terminal)

$ eval `gcloud beta emulators pubsub env-init`
$ cd path/to/your-app
$ bundle exec activejob-google_cloud_pubsub-worker

If you hit the previous action, the job will be executed. (Both the emulator and the worker stop with Ctrl+C)

When passing options to the adapter, you need to create the object instead of a symbol.

Rails.application.config.active_job.queue_adapter = ActiveJob::GoogleCloudPubsub::Adapter.new(
  async:  false,
  logger: Rails.logger,

  pubsub: Google::Cloud::Pubsub.new(
    project: 'MY-PROJECT-ID',
    keyfile: 'path/to/keyfile.json'
  )
)

Whether to publish messages asynchronously.

Default: true

The logger that outputs a message publishing error. Specify nil to disable logging.

Default: Logger.new($stdout)

The instance of Google::Cloud::Pubsub::Project. Please see Google::Cloud::Pubsub.new for details.

Default: Google::Cloud::Pubsub.new

The following command line flags can be specified. All flags are optional.

The path of the file to load before the worker starts up.

Default: ./config/environment

The name of the queue the worker handles.

Note: One worker can handle only one queue. If you use multiple queues, you need to launch multiple worker processes.

Default: default

Minimum number of worker threads.

Default: 0

Maximum number of worker threads.

Default: number of logical cores

Credentials of Google Cloud Platform. Please see the document for details.

$ bundle exec rake spec

Bug reports and pull requests are welcome on GitHub at https://github.com/ursm/activejob-google_cloud_pubsub.

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