mysql-backup.rb

#!/usr/bin/env ruby
#Pre-requisite: gem install mail (https://github.com/mikel/mail)
require 'mail'

mysql_username = 'root'
mysql_password = '123456'
mysql_database = 'your database'  # consider use of ARGV

file_suffix = Time.new.strftime('%Y%m%d_%H%M%S')
mysql_backup_file = "backup-#{mysql_database}-#{file_suffix}.sql.gz" 

user_email='xxxxx@gmail.com'
user_password='your gmail password  or app specific password'  #see https://support.google.com/mail/answer/1173270?hl=en

# MySql Dump and compress backup in .gz
print "Executing backup... "
cmd = "mysqldump --user=#{mysql_username} --password=#{mysql_password} #{mysql_database} | gzip -c  > #{mysql_backup_file}"
ok = system(cmd)
exit(1) if !ok 

print "Send backup to email... "
# Credit to : 
# http://stackoverflow.com/questions/12884711/how-to-send-email-via-smtp-with-rubys-mail-gem
options = { 
    :address              => "smtp.gmail.com",
    :port                 => 587,
    :domain               => user_email,
    :user_name            => user_email,
    :password             => user_password,
    :authentication       => 'plain',
    :enable_starttls_auto => true  
}

Mail.defaults do
  delivery_method :smtp, options
end

Mail.deliver do
  from     options[:user_name]
  to       options[:user_name]
  subject  "Database #{mysql_database} backup #{Time.new}"
  body     "Database #{mysql_database} backup #{Time.new}"
  add_file mysql_backup_file
end

File.delete mysql_backup_file
print "Finish ok"