docs: def apply_minion_config(overrides=None,
                          defaults=None,
                          cache_minion_id=False,
                          minion_id=None):
      '''
      Returns minion configurations dict.
      '''
      if defaults is None:
          defaults = DEFAULT_MINION_OPTS.copy()
      if overrides is None:
          overrides = {}
  
      opts = defaults.copy()
      opts['__role'] = 'minion'
      _adjust_log_file_override(overrides, defaults['log_file'])
      if overrides:
          opts.update(overrides)
  
      if 'environment' in opts:
          if opts['saltenv'] is not None:
              log.warning(
                  'The \'saltenv\' and \'environment\' minion config options '
                  'cannot both be used. Ignoring \'environment\' in favor of '
                  '\'saltenv\'.',
              )
              # Set environment to saltenv in case someone's custom module is
              # refrencing __opts__['environment']
              opts['environment'] = opts['saltenv']
          else:
              log.warning(
                  'The \'environment\' minion config option has been renamed '
                  'to \'saltenv\'. Using %s as the \'saltenv\' config value.',
                  opts['environment']
              )
              opts['saltenv'] = opts['environment']
  
      for idx, val in enumerate(opts['fileserver_backend']):
          if val in ('git', 'hg', 'svn', 'minion'):
              new_val = val + 'fs'
              log.debug(
                  'Changed %s to %s in minion opts\' fileserver_backend list',
                  val, new_val
              )
              opts['fileserver_backend'][idx] = new_val
  
      opts['__cli'] = salt.utils.stringutils.to_unicode(
          os.path.basename(sys.argv[0])
      )
  
      # No ID provided. Will getfqdn save us?
      using_ip_for_id = False
      if not opts.get('id'):
          if minion_id:
              opts['id'] = minion_id
          else:
              opts['id'], using_ip_for_id = get_id(
                      opts,
                      cache_minion_id=cache_minion_id)
  
      # it does not make sense to append a domain to an IP based id
      if not using_ip_for_id and 'append_domain' in opts:
          opts['id'] = _append_domain(opts)
  
      for directory in opts.get('append_minionid_config_dirs', []):
          if directory in ('pki_dir', 'cachedir', 'extension_modules'):
              newdirectory = os.path.join(opts[directory], opts['id'])
              opts[directory] = newdirectory
          elif directory == 'default_include' and directory in opts:
              include_dir = os.path.dirname(opts[directory])
              new_include_dir = os.path.join(include_dir,
                                             opts['id'],
                                             os.path.basename(opts[directory]))
              opts[directory] = new_include_dir
  
      # pidfile can be in the list of append_minionid_config_dirs, but pidfile
      # is the actual path with the filename, not a directory.
      if 'pidfile' in opts.get('append_minionid_config_dirs', []):
          newpath_list = os.path.split(opts['pidfile'])
          opts['pidfile'] = os.path.join(newpath_list[0], 'salt', opts['id'], newpath_list[1])
  
      if len(opts['sock_dir']) > len(opts['cachedir']) + 10:
          opts['sock_dir'] = os.path.join(opts['cachedir'], '.salt-unix')
  
      # Enabling open mode requires that the value be set to True, and
      # nothing else!
      opts['open_mode'] = opts['open_mode'] is True
      opts['file_roots'] = _validate_file_roots(opts['file_roots'])
      opts['pillar_roots'] = _validate_pillar_roots(opts['pillar_roots'])
      # Make sure ext_mods gets set if it is an untrue value
      # (here to catch older bad configs)
      opts['extension_modules'] = (
          opts.get('extension_modules') or
          os.path.join(opts['cachedir'], 'extmods')
      )
      # Set up the utils_dirs location from the extension_modules location
      opts['utils_dirs'] = (
          opts.get('utils_dirs') or
          [os.path.join(opts['extension_modules'], 'utils')]
      )
  
      # Insert all 'utils_dirs' directories to the system path
      insert_system_path(opts, opts['utils_dirs'])
  
      # Prepend root_dir to other paths
      prepend_root_dirs = [
          'pki_dir', 'cachedir', 'sock_dir', 'extension_modules', 'pidfile',
      ]
  
      # These can be set to syslog, so, not actual paths on the system
      for config_key in ('log_file', 'key_logfile'):
          if urlparse(opts.get(config_key, '')).scheme == '':
              prepend_root_dirs.append(config_key)
  
      prepend_root_dir(opts, prepend_root_dirs)
  
      # if there is no beacons option yet, add an empty beacons dict
      if 'beacons' not in opts:
          opts['beacons'] = {}
  
      if overrides.get('ipc_write_buffer', '') == 'dynamic':
          opts['ipc_write_buffer'] = _DFLT_IPC_WBUFFER
  
      # Make sure hash_type is lowercase
      opts['hash_type'] = opts['hash_type'].lower()
  
      # Check and update TLS/SSL configuration
      _update_ssl_config(opts)
      _update_discovery_config(opts)
  
      return opts