In case anyone is looking to simplify cross-component communication using Pub/Sub on GCP, we've open sourced a gem to do just that. For those familiar with Sidekiq, writing publishers and subscribers is very similar to writing workers.
Full blog post: https://www.keypup.io/blog/gcp-pub-sub-with-ruby-on-rails
Gem documentation: https://github.com/keypup-io/cloudenvoy
Feedback on the gem is welcome! Feel to request any functionality.