Migrate from Heroku Shared DB to Postgres `dev` Plan

migrate.rb

#!/usr/bin/env ruby
#
# This script migrates your Heroku app from a Shared DB to a Postgres `dev` Plan
#
# Usage:
#   ruby migrate.rb [app_name]
#

def usage
  puts "migrate.rb [app_name]"
  exit 0
end

def app_name
  ARGV.first or usage
end

def heroku(cmd)
  full_cmd = "heroku #{cmd} -a #{app_name}"
  puts full_cmd

  system full_cmd
end

def heroku!(cmd)
  heroku(cmd) or exit 1
end

def db_name
  return @db_name if @db_name

  config_output = `heroku config -a #{app_name} | grep POSTGRESQL`
  @db_name = config_output.match(/(HEROKU_POSTGRESQL_\w+)_URL/)[1]
  raise "Can't extract db_color from config_output" if @db_name.nil?

  @db_name
end

puts "Let's migrate #{app_name} over to Heroku Postgres Dev Plan"

heroku "addons:add heroku-postgresql:dev"
heroku "addons:add pgbackups"
heroku! "maintenance:on"
heroku! "pgbackups:capture --expire"
heroku! "pgbackups:restore #{db_name} --confirm #{app_name}"
heroku! "pg:promote #{db_name}"
heroku! "maintenance:off"
heroku! "addons:remove shared-database --confirm #{app_name}"


puts "Done!"