setup for Active Storage direct upload ( Google Cloud Storage )

active_storage.rake

# lib/tasks/active_storage.rake

require 'google/cloud/storage'

namespace :active_storage do
  desc 'create bucket'
  task :create_bucket, [:bucket_name, :domain] => :environment do |task, args|
    storage.create_bucket(args.bucket_name, location: 'us-east1') do |b|
      b.cors.add_rule ["http://#{args.domain}", "https://#{args.domain}"],
                      '*',
                      headers: ['Content-Type', 'Content-Md5'],
                      max_age: 3600
    end
  end

  desc 'cleanup buckets'
  task :cleanup_bucket, [:bucket_name] => :environment do |task, args|
    ActiveStorage::Attachment.in_batches.each_record(&:purge)
    storage.bucket(args.bucket_name).delete
  end
end

private

def storage
  Google::Cloud::Storage.new(credentials: credentials)
end


def credentials
  Google::Cloud::Storage::Credentials.new(
    {
      project_id: ENV.fetch('GCS_PROJECT_ID'),
      private_key: ENV.fetch('GCS_PRIVATE_KEY').gsub("\\n", "\n"),
      private_key_id: ENV.fetch('GCS_PRIVATE_KEY_ID'),
      client_email: ENV.fetch('GCS_CLIENT_EMAIL'),
      client_id: ENV.fetch('GCS_CLIENT_ID'),
      client_x509_cert_url: ENV.fetch('GCS_X509_CERT_URL')
    }
  )
end

app.json

{
  "scripts": {
    "postdeploy": "bin/rails heroku_review_apps:setup",
    "pr-predestroy": "bin/rails heroku_review_apps:cleanup"
  },
}

heroku_review_apps.rake

# lib/tasks/heroku_review_apps.rake
# need ENV['HEROKU_APP_NAME']
namespace :heroku_review_apps do
  desc 'create bucket for Heroku Reivew Apps'
  task setup: :environment do
    Rake::Task['active_storage:create_bucket'].invoke(ENV['HEROKU_APP_NAME'], "#{ENV['HEROKU_APP_NAME']}.herokuapp.com")
    ENV['FIXTURES'] = 'users,projects,tracks' # Workaround ActiveRecord::InvalidForeignKey: PG::ForeignKeyViolation: ERROR: insert or update on table "tracks" violates foreign key constraint "fk_rails_xxxxx"
    Rake::Task['db:fixtures:load'].invoke
  end

  desc 'cleanup buckets using Heroku Review Apps'
  task cleanup: :environment do
    Rake::Task['active_storage:cleanup_bucket'].invoke(ENV['HEROKU_APP_NAME'], "#{ENV['HEROKU_APP_NAME']}.herokuapp.com")
  end
end