docs: def config_filename(filename):
      """
          Obtains the first filename found that is included in one of the configuration folders.
          This function returs the full path for the file.
          
          * It is useful for files that are not config-formatted (e.g. hosts files, json, etc.)
            that will be read using other mechanisms
      """
      global _ETC_PATHS
      if filename.startswith('/'):
          _LOGGER.info("using absolute path for filename \"%s\"" % filename)
          return filename
  
      import os.path
      for fpath in _ETC_PATHS:
          current_path = "%s/%s" % (fpath, filename)
          if os.path.isfile(current_path):
              current_path = os.path.realpath(current_path)
              _LOGGER.info("using path \"%s\" for filename \"%s\"" % (current_path, filename))
              return current_path
  
      _LOGGER.info("using path \"%s\" for filename \"%s\"" % (filename, filename))
      return filename