old_contents: class Service(object):
      """
      A service is a long-running process that provides chute functionality.
      """
  
      def __init__(self,
                   chute=None,
                   name=None,
                   type="normal",
                   image=None,
                   command=None,
                   dockerfile=None,
                   build=None,
                   environment=None,
                   interfaces=None,
                   requests=None):
          self.chute = chute
          self.name = name
  
          self.type = type
          self.image = image
          self.command = command
          self.dockerfile = dockerfile
  
          if build is None:
              self.build = {}
          else:
              self.build = build
  
          if environment is None:
              self.environment = {}
          else:
              self.environment = environment
  
          if interfaces is None:
              self.interfaces = {}
          else:
              self.interfaces = interfaces
  
          if requests is None:
              self.requests = {}
          else:
              self.requests = requests
  
      def get_container_name(self):
          """
          Get the name for the service's container.
  
          This will be a combination of the chute name and the service name.
          """
          if self.name is None:
              # name can be None for old-style single-service chutes where the
              # container name is expected to be the name of the chute.
              return self.chute.name
          else:
              return "{}-{}".format(self.chute.name, self.name)
  
      def get_image_name(self):
          """
          Get the name of the image to be used.
          """
          if self.image is not None:
              return self.image
          else:
              return "{}:{}".format(self.get_container_name(), self.chute.version)
  
new_contents: class Service(object):
      """
      A service is a long-running process that provides chute functionality.
      """
  
      def __init__(self,
                   chute=None,
                   name=None,
                   type="normal",
                   image=None,
                   command=None,
                   dockerfile=None,
                   build=None,
                   environment=None,
                   interfaces=None,
                   requests=None):
          self.chute = chute
          self.name = name
  
          self.type = type
          self.image = image
          self.command = command
          self.dockerfile = dockerfile
  
          if build is None:
              self.build = {}
          else:
              self.build = build
  
          if environment is None:
              self.environment = {}
          else:
              self.environment = environment
  
          if interfaces is None:
              self.interfaces = {}
          else:
              self.interfaces = interfaces
  
          if requests is None:
              self.requests = {}
          else:
              self.requests = requests
  
      def get_container_name(self):
          """
          Get the name for the service's container.
  
          This will be a combination of the chute name and the service name.
          """
          if self.name is None:
              # name can be None for old-style single-service chutes where the
              # container name is expected to be the name of the chute.
              return self.chute.name
          else:
              return "{}-{}".format(self.chute.name, self.name)
  
      def get_image_name(self):
          """
          Get the name of the image to be used.
          """
          # Light chute services have a shorthand image name like "python2" that
          # should not be interpreted as an actual Docker image name.
          if self.image is None or self.type == "light":
              return "{}:{}".format(self.get_container_name(), self.chute.version)
          else:
              return self.image
  
subject: Fix get_image_name for light chutes.