rails rake task for backing up heroku database to s3 bucket

backup_db_to_s3.rake

# this gist was inspired by hopsoft's
#   https://gist.github.com/hopsoft/56ba6f55fe48ad7f8b90
# and a snippet given to me by mckbeardy on Midwest Dev Chat (Zach Mckenzie)

# put this file in lib/tasks
#   your_rails_project/lib/tasks/backup_db_to_s3.rake  (or whatever you want to name it)
#
# usage:
#
# rails db:backup_to_s3
#    or
# rake db:backup_to_s3
#
# personally, i made a task with heroku scheduler to automatically backup the db in the
# middle of the night
#
# feel free to ask any questions.



require 'aws-sdk'
namespace :db do

  task :backup_to_s3 => :environment do
    file_name = (->{
      time = Time.now
      host = ENV['HOST']
      host = host.instance_of?(String) ? host.split('.')[0] : nil

      [
        'DB backup',
        host,
        time.strftime("%Y-%m-%d"),
        time.strftime("%H.%M.%S.%L_%Z")
      ].compact.join('__') + '.dump'
    }).call

    file_name_with_full_path = "#{Rails.root}/db/#{file_name}"

    app = Rails.application.class.parent_name.underscore

    host, db, user, password = (->{
      config = ActiveRecord::Base.connection_config
      [:host, :database, :username, :password].map{|k| config[k]}
    }).call

    run("echo #{host}:5432:#{db}:#{user}:#{password} > ~/.pgpass")
    run([
      'pg_dump',
      "--host #{host}",
      "--username #{user}",
      '--verbose',
      '--clean',
      '--no-owner',
      '--no-acl',
      '--format=c',
      "--dbname #{db}",
      '--no-password',
      "> #{file_name_with_full_path}"
    ].join(' '))

    s3 = Aws::S3::Resource.new(region: ENV['AWS_REGION'])
    obj = s3.bucket(ENV['S3_BUCKET_NAME']).object(file_name)
    puts "Uploading file #{file_name}"
    obj.upload_file(file_name_with_full_path)
    puts "Done"
  end


  private

  def run(str)
    puts str
    system str
  end

end