how to auto-mount an osx time machine sparsebundle over a nas drive

readme.md

installation

1. save the .rb file in ~/bin
2. save the .plist file in ~/Library/LaunchAgents
3. run brew install terminal-notifier terminal-notifier
4. change .plist parameters
5. run launchctl load ~/Library/LaunchAgents/local.timemachine.drive.plist

It will show a notification when mount is completed.

local.timemachine.drive.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Label</key>
	<string>local.timemachine.drive</string>
	<key>ProgramArguments</key>
	<array>
		<string>ruby</string>
    <!--  change these parameters -->
		<string>FULL_PATH_TO_THE_RUBY_FILE_|_YOU_CAN_SAVE_IN_HOME_BIN_DIR</string>
		<string>FULL_PATH_TO_YOUR_NAS_SAMBA_DIRECTORY_|_EX_//guest:@192.168.1.1/NAS_DRIVE_MOUNT_NAME</string>
		<string>NAS_DRIVE_MOUNT_NAME_|_EX_samba_drive</string>
		<string>TIME_MACHINE_MOUNT_NAME_|_EX_tm_drive</string>
		<string>/Volumes/NAS_DRIVE_MOUNT_NAME/PATH/TO/YOUR.sparsebundle</string>
    <!--  change these parameters -->
	</array>
	<key>RunAtLoad</key>
	<true/>
	<key>StartInterval</key>
	<integer>60</integer>
</dict>
</plist>

notification.png

timemachine.drive.rb

require "pathname"
require "shellwords"

class AutoTimeMachineDrive
  class << self
    def mount!
      new.mount_timemachine_drive
    rescue => ex
      notify(ex.message)
    end

    def notify(message)
      options = {
        group:   self.to_s,
        title:   self.to_s,
        message: message,
        sound:   :default
      }

      system "/usr/local/bin/terminal-notifier #{option_line options}"
    end

    def option_line(*options)
      options.collect do |element|
        case element
        when Hash
          element.collect{|k, v| "-#{k} #{Shellwords.escape v}"}.join " "
        when String, Pathname
          element.to_s
        end
      end.join " "
    end
  end

  def initialize
    @smb_url, @smb_mount_name,
    @time_machine_mount_name, @time_machine_sparsebundle_file_path = ARGV
  end

  def mount_timemachine_drive
    return if tm_mount_point.exist?

    ensure_smb_mount_point do
      ensure_tm_mount_point_is_missing do
        mount_timemachine_sparsebundle_file
        self.class.notify("#{time_machine_mount_name} mounted.") if tm_mount_point.exist?
      end
    end
  end

  private
    attr_reader :smb_url, :smb_mount_name,
                :time_machine_mount_name, :time_machine_sparsebundle_file_path

    def smb_mount_point
      Pathname "/Volumes/#{smb_mount_name}"
    end

    def tm_mount_point
      Pathname "/Volumes/#{time_machine_mount_name}"
    end

    def ensure_smb_mount_point
      prepare_smb_mount_point do
        mount_samba
        yield
      end
    end

    def ensure_tm_mount_point_is_missing
      yield unless tm_mount_point.exist?
    end

    def prepare_smb_mount_point
      if smb_mount_point.exist?
        if [smb_mount_point_not_network_drive?, smb_mount_point_not_empty?].all?
          return self.class.notify "unempty smb_mount_point (#{smb_mount_point}) exists. make sure this directory is removed before running."
        end
      else
        smb_mount_point.mkdir
      end

      yield
    end

    def smb_mount_point_not_network_drive?
      `mount`.lines.select{|line| line.include? smb_mount_point.to_s }.count == 0
    end

    def smb_mount_point_is_network_drive?
      not smb_mount_point_not_network_drive?
    end

    def smb_mount_point_not_empty?
      smb_mount_point.children.count > 0
    end

    def mount_samba
      return if smb_mount_point_is_network_drive?
      system "mount_smbfs #{self.class.option_line(smb_url, smb_mount_point)}"
    end

    def mount_timemachine_sparsebundle_file
      system "hdiutil attach #{self.class.option_line(
          {mountpoint: tm_mount_point},
          time_machine_sparsebundle_file_path
        )}"
    end

end


AutoTimeMachineDrive.mount!