Sidekiq worker for publishing queue size metric to AWS CloudWatch

sidekiq-worker-cloudwatch-queue-size.rb

class QueueSizeMetricWorker
  include Sidekiq::Worker
  include Sidetiq::Schedulable

  recurrence { minutely }
  sidekiq_options retry: false

  # Publish a custom metric on CloudWatch with the Sidekiq queue size
  def perform
    cloudwatch = Aws::CloudWatch::Client.new(
      region: 'us-east-1',
      credentials: Aws::Credentials.new(ENV['AWS_KEY'], ENV['AWS_SECRET'])
    )
    cloudwatch.put_metric_data(
      namespace: 'Worker',
      metric_data: [{
        metric_name: 'QueueSize',
        dimensions: [{
          name: 'Environment',
          value: Rails.env
        }],
        value: queue_size,
        unit: 'Count'
      }]
    )
  end

  def queue_size
    stats = Sidekiq::Stats.new
    stats.queues.values.inject 0, :+
  end
end