Update background Image to National Geographic Photo of the day

Rakefile

TODAY = Time.now.strftime("%Y-%m-%d")
USER = "MY_USER"
PICTURES_DIR = "/home/#{USER}/Pictures/national-geographic/"
TODAYS_PICTURE = "#{PICTURES_DIR}#{TODAY}-ngeo.jpg"
PROXY_HOST = 'proxy.example.net'
PROXY_PORT = 8443

desc "Fetch National Geographic Photo of the Day"
task :get_photo_of_the_day do
  # http://photography.nationalgeographic.com/photography/photo-of-the-day/

  NG_IMAGES_HOSTNAME = "images.nationalgeographic.com"
  page = ""
  proxy = Net::HTTP::Proxy(PROXY_HOST, PROXY_PORT)

  proxy.start("photography.nationalgeographic.com") do |http|
    page = http.get('/photography/photo-of-the-day/')
  end
  image_path = page.body.match(/#{NG_IMAGES_HOSTNAME}(.+\.jpg)/)[1]
  proxy.start(NG_IMAGES_HOSTNAME) do |http|
    image = http.get(image_path)
    File.open(TODAYS_PICTURE, "w") do |file|
      file.write image.body
    end
  end
end

desc "Update Background Image"
task :update_background_image do
  unless File.exists?(TODAYS_PICTURE)
    Rake::Task["get_photo_of_the_day"].invoke
  end
  system %Q{gsettings set org.gnome.desktop.background picture-uri file://#{TODAYS_PICTURE}}
end