backup.rb

require 'fog'
require 'net/ssh'

pretend = false

backup_volumes = {
  'hostname' => [
    {
      :device => '/dev/xvdf',
      :mount  => '/srv/mongo'
    }
  ]
}

now           = Time.now
now_date      = now.strftime('%Y-%m-%d')
now_time      = now.strftime('%H:%M:%S')
now_datetime  = [ now_date, now_time ].join(' ')

puts '. Starting Backup Process %s' % now_datetime

AWS = Fog::Compute.new({
  :provider              => 'AWS',
  :aws_access_key_id     => '',
  :aws_secret_access_key => ''
})

ssh_user    = 'ec2_user'
ssh_options = {
  :auth_methods   => [ 'publickey' ],
  :forward_agent  => false
}

puts '. Grabbing Server Info'
servers = {}
AWS.servers.each do |server|
  servers[server.tags['Name']] = server
end

backup_volumes.each_pair do |srv, volumes|
  volumes.each do |volume|
    start         = Time.now
    server        = servers[srv]
    device        = volume[:device]
    mount         = volume[:mount]
    snapshots     = []

    puts '.. Connecting to %s as %s' % [ srv, ssh_user ]
    Net::SSH.start(srv, ssh_user, ssh_options) do |ssh|
      puts '.. MongoDB Flushing to Disk'
      ssh.exec!("mongo --eval 'db.runCommand({fsync:1,lock:1});' admin") unless pretend

      puts '.. Syncing disks'
      ssh.exec!('sync') unless pretend

      server.volumes.all('tag-value' => '%s %s' % [ srv, mount ]).each do |vol|
        puts '... %s [ %s => %s ]' % [ srv, mount, vol.id ]
        snapshots << vol.snapshots.create unless pretend
      end

      puts '.. MongoDB Unlocking Tables'
      ssh.exec!("mongo --eval 'db.$cmd.sys.unlock.findOne();' admin") unless pretend
    end

    puts '.. Tagging Snapshots'
    snapshots.each do |snapshot|
      snapshot.reload
      {
        'Name'        => '%s %s' % [ srv, mount ],
        'backup_date' => now_date,
        'backup_time' => now_time
      }.each_pair do |k,v|
        AWS.tags.create(
          :key            => k,
          :value          => v,
          :resource_id    => snapshot.id,
          :resource_type  => 'snapshot'
        )
      end
    end

    puts '.. Done (%.2f)' % (Time.now - start)
  end
end