gistfile1.rb

require 'octopi'
require 'pp'

module Github; end

class Github::Backup

  include Octopi

  attr_reader :backup_root, :debug

  def initialize(backup_root)
    @backup_root = backup_root
    @debug = false
  end

  def config
    read_gitconfig["github"]
  end

  def execute
    FileUtils::mkdir_p(backup_root)
    authenticated do |api|
      repositories = User.find(config["user"]).repositories.sort_by { |r| r.name }
      repositories.each do |repository|
        puts "Backing up: #{repository.name}"
        backup_repository repository
      end
    end
  rescue Errno::ENOENT
    puts "Please install git and create a ~/.gitconfig"
    puts "  See: http://github.com/guides/tell-git-your-user-name-and-email-address"
  rescue NoMethodError
    puts "Please add a [github] section to your ~/.gitconfig"
    puts "  See: http://github.com/guides/tell-git-your-user-name-and-email-address"
  end

private ######################################################################

  def backup_directory_for(repository)
    File.join(backup_root, repository.name)
  end

  def backup_repository(repository)
    if File.exists?(backup_directory_for(repository))
      backup_repository_incremental(repository)
    else
      backup_repository_initial(repository)
    end
  end

  def backup_repository_initial(repository)
    FileUtils::cd(backup_root) do
      shell("git clone -n #{repository.clone_url}")
    end
  end

  def backup_repository_incremental(repository)
    FileUtils::cd(backup_directory_for(repository)) do
      shell("git remote update")
    end
  end

  def shell(command)
    puts "EXECUTING: #{command}" if debug
    IO.popen(command, 'r') do |io|
      output = io.read
      puts "OUTPUT:" if debug
      puts output if debug
    end
  end

end