Retry n times on specified exceptions

with_retries.rb

# USAGE: retry 3 times on specified errors and wait 5s between retries
# when maximum retries is run then raise exception

# with_retries(on: [Errno::EHOSTUNREACH], tries: 3, interval: 5) do
#   Net::HTTP.get('example.com', '/index.html')
# end

module WithRetries
  def with_retries(on: [StandardError], tries: 3, interval: 0.5)
    interval = 0 if Rails.env.test? # speed up tests
    retries = 0

    begin
      yield
    rescue *on => e
      if retries < tries
        retries += 1
        Rails.logger.info "Retry ##{retries} due to error: #{e.class}"
        sleep(interval) and retry
      else
        Rails.logger.info "Failed after #{retries} retries: #{e.class}"
        raise
      end
    end
  end
end