sub.rb

require 'google/cloud/pubsub'
require 'json'

pubsub = Google::Cloud::Pubsub.new(project_id: ENV['GCP_PROJECT_ID'])

count = {}
data = []

sub = pubsub.subscription ENV['PUBSUB_SUBSCRIPTION']
retry_count = 0
1.step do |i|
  messages = sub.pull(max: 1000)
  messages.each do |m|
    data << { 'id' => m.data.to_i, 'index' => i }
    count[m.data] ||= 0
    count[m.data] += 1
  end

  sub.acknowledge messages

  puts messages.length
  if messages.empty?
    retry_count += 1
    # retry 3 times
    break if retry_count > 3
  end
end

File.open('count.json', 'w') do |f|
  JSON.dump(count, f)
end

File.open('data.json', 'w') do |f|
  JSON.dump(data, f)
end