rake database dump

namespace :db do
  desc "Backup database to #{RAILS_ROOT}/db/backup"
  task :backup => :environment do
    max_backups = (ENV["MAX"] || 14).to_i
    timestamp = Time.now.strftime("%Y%m%d_%H%M%S")
    backup_folder = File.join("db", "backup")
    backup_file = File.join(backup_folder, "#{RAILS_ENV}_dump_#{timestamp}.sql.gz")
    FileUtils.makedirs(backup_folder)
    db_config = ActiveRecord::Base.configurations[RAILS_ENV]
    command = "mysqldump -u #{db_config['username']} -p#{db_config['password']} --default-character-set=utf8 --single-transaction --quick #{db_config['database']} | gzip -c > #{backup_file}"
    command = command.sub(/mysqldump/, "mysqldump -h #{db_config['host']}") unless db_config['host'].nil?
    sh command
    puts "+ Created backup: #{backup_file}"
    dir = Dir.new(backup_folder)
    all_backups = dir.entries.select {|e| e.to_s =~ /#{RAILS_ENV}/}.sort.reverse
    unwanted_backups = all_backups[max_backups..-1] || []
    unwanted_backups.each do |unwanted_backup|
      FileUtils.rm_rf(File.join(backup_folder, unwanted_backup))
      puts "- Deleted backup: #{unwanted_backup}"
    end
  end
end