Class: Snapback::App::Snapshot

Inherits:
Object
  • Object
show all
Includes:
Singleton
Defined in:
lib/snapback/app/snapshot.rb

Instance Method Summary collapse

Instance Method Details

#go ⇒ Object 



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# File 'lib/snapback/app/snapshot.rb', line 8

def go
  # Ensure we have a size parameter
  if $options[:size].nil? then
    raise "You must specify a size attribute. E.g.: -s 100M"
  end

  if !$database.db_exists?($options[:database]) then
    raise "Database '#{$options[:database]}' does not exist"
  end

  volume_group_name = "#{$config['lvm']['volume_group']}"
  logical_volume_name = "#{$config['lvm']['prefix_database']}-#{$options[:database]}"
  mount_dir = get_mount_dir $options[:database]
  mysql_data_dir = $database.get_data_dir

  # Flush the MySQL Logs
  exec_flush

  # Stop the MySQL Server
  $database.server_stop

  on_rollback lambda {
    $database.server_start
  }

  # Unlink
  exec_unlink "#{mysql_data_dir}/#{$options[:database]}", mount_dir

  # Unmount
  exec_unmount "/dev/#{volume_group_name}/#{logical_volume_name}", mount_dir

  # Deactivate
  exec_deactivate "/dev/#{volume_group_name}/#{logical_volume_name}"
  
  # Branch the logical volume with a snapshot
  run "Snapshot the logical volume",
    "lvcreate -L #{$options[:size]} -s -n #{$config['lvm']['prefix_backup']}-#{$options[:database]} /dev/#{volume_group_name}/#{logical_volume_name}"

  on_rollback lambda {
    run "Remove the snapshot",
      "lvremove /dev/#{volume_group_name}/#{$config['lvm']['prefix_backup']}-#{$options[:database]}"
  }

  # Active the master drive
  exec_activate "/dev/#{volume_group_name}/#{logical_volume_name}"

  # Mount the master drive
  exec_mount "/dev/#{volume_group_name}/#{logical_volume_name}", mount_dir

  # Symbolic-link the MySQL data directory to the new logical volume
  # ln -s /mnt/mysql/{dbName} {mysql-data-dir}/{dbName}/
  exec_link "#{mysql_data_dir}/#{$options[:database]}", mount_dir

  # Change the permissions & ownership to MySQL
  exec_chown "#{mysql_data_dir}/#{$options[:database]}"
  exec_chown mount_dir

  # Start the MySQL Server
  $database.server_start

  on_rollback lambda {
    $database.server_stop
  }
end