Running background workers on Heroku without paying for extra dynos

daemonized-worker

# Adjust according to your own needs
# Be sure to chmod +x before committing
# Store this in your app's 'bin/' directory
if [[ $DAEMONIZED_WORKER_CONCURRENCY -gt 0 ]]; then
  # Adjust the '-q' flags as you need them, or swap this out for Resque or Delayed::Job
  bundle exec sidekiq --concurrency $DAEMONIZED_WORKER_CONCURRENCY -q mailer,2 -q default --verbose;
fi;

Procfile

console: bundle exec rails console
rake: bundle exec rake
web: daemonized-worker & web
worker: worker

web

# Adjust according to your own needs
# Be sure to chmod +x before committing
# Store this in your app's 'bin/' directory
bundle exec unicorn -c config/unicorn.rb -E $RACK_ENV -p $PORT config.ru --no-default-middleware