code: def read_configuration(key, path=None, default=None, single_config=False, fallback_to_env=True):
      
  
      if path and os.path.exists(path):
          with open(path, 'r') as config_file:
              if single_config:
                  return config_file.read()
  
              for line in config_file:
                  if line.startswith('%s=' % key):
                      return line.split('=', 1)[1].strip()
  
      if fallback_to_env and key in os.environ:
          return os.environ[key]
  
      return default
docs: Read configuration from a file, Docker config or secret or from the environment variables.
  
      :param key: the configuration key
      :param path: the path of the configuration file (regular file or Docker config or secret)
      :param default: the default value when not found elsewhere (default: `None`)
      :param single_config: treat the configuration file as containing the full configuration,
          otherwise the file is expected to be a '=' separated key-value list line by line
          (default: `False`)
      :param fallback_to_env: look for the configuration key in the environment variables
          if not found elsewhere (default: `True`)