An automated Ruby script for grabbing the latest Mac Chromium build

chromium_updater.rb

#!/usr/bin/env ruby

# A simple Ruby script to update Chromium from dev build.
# Currently only works on Mac.  You should be able extend it to Linux and Windows without much fuzz.  
# If you want progress bar, sudo gem install ruby-progressbar
# Usage:
#   ruby chromium_updater.rb 

require 'fileutils'
require 'open-uri'
require 'tmpdir'

module ChromiumBuild
  BUILD_SNAPSHOT_URL = 'http://build.chromium.org/f/chromium/snapshots.old'
  
  class Updater
    attr_accessor :install_path, :build_dir, :platform
    
    def initialize( install_path, build_dir, platform )
      self.install_path = install_path
      self.build_dir = build_dir
      self.platform = platform.to_s
      puts "#{BUILD_SNAPSHOT_URL}/#{@platform}/LATEST"
      @latest_revision_uri = URI.parse("#{BUILD_SNAPSHOT_URL}/#{@platform}/LATEST")
    end
    
    
    def update
      build
      unpack
      cleanup
    end
    
    
    def unpack
      ## platform specific
    end
    
    
    def cleanup
      ## platform specific
    end
    
    
    def build
      @build ||= get_build
    end
    
    
    begin
      # sudo gem install ruby-progressbar
      require 'rubygems'
      require 'progressbar'
      def get_build
        @build = File.open(File.join(build_dir, build_filename), 'w')
        progress_bar = nil
        Net::HTTP.start(latest_build_uri.host) do |http|
          progress_bar = ProgressBar.new('progress', http.head(latest_build_uri.path).content_length)
          progress_bar.file_transfer_mode
          http.get(latest_build_uri.path) do |data|
            @build.write(data) 
            progress_bar.inc(data.size)
          end
        end
      ensure
        @build.close
        progress_bar && progress_bar.finish
        return @build        
      end
    rescue LoadError => e
      def get_build
        @build = File.open(File.join(build_dir, build_filename), 'w')
        @build.write(latest_build_uri.read)
      ensure
        @build.close
        return @build
      end
    end
    
    
    def latest_revision
      @latest_revision ||= get_latest_revision
    end
    
    
    protected
      
      def latest_build_uri
        URI.parse "#{BUILD_SNAPSHOT_URL}/#{@platform}/#{latest_revision}/#{build_filename}"
      end
      
      
      def get_latest_revision
        @latest_revision = @latest_revision_uri.read
      end
      
      
      def build_filename
        "#{build_basename}.zip"
      end
      
      
      def build_basename
        "chrome-#{@platform.downcase}"
      end
      
  end
  
  
  class MacUpdater < Updater
    def initialize( install_path='/Applications/Chromium.app', build_dir=Dir.tmpdir )
      super(install_path, build_dir, 'Mac')
    end
    
    
    def unpack
      `unzip #{build.path} -d #{build_dir}`
      FileUtils.rm_rf install_path
      FileUtils.cp_r  extracted_app_path, install_path, :verbose => true
    end
    
    
    def cleanup
      FileUtils.rm_rf Dir.glob(File.join(build_dir, "#{build_basename}*")), :verbose => true
    end
    
    
    private 
          
      def extracted_app_path
        File.join build_dir, build_basename, 'Chromium.app'
      end
      
  end
  
end


if __FILE__ == $0
  updater = ChromiumBuild::MacUpdater.new
  puts "Downloading rev ##{updater.latest_revision}..."
  updater.get_build
  puts "Unpacking..."
  updater.unpack
  puts "Cleaning up..."
  updater.cleanup
  puts "All done!"
end