docs: def file_exists(path, saltenv=None):
      '''
      .. versionadded:: 2016.3.0
  
      This is a master-only function. Calling from the minion is not supported.
  
      Use the given path and search relative to the pillar environments to see if
      a file exists at that path.
  
      If the ``saltenv`` argument is given, restrict search to that environment
      only.
  
      Will only work with ``pillar_roots``, not external pillars.
  
      Returns True if the file is found, and False otherwise.
  
      path
          The path to the file in question. Will be treated as a relative path
  
      saltenv
          Optional argument to restrict the search to a specific saltenv
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' pillar.file_exists foo/bar.sls
      '''
      pillar_roots = __opts__.get('pillar_roots')
      if not pillar_roots:
          raise CommandExecutionError('No pillar_roots found. Are you running '
                                      'this on the master?')
  
      if saltenv:
          if saltenv in pillar_roots:
              pillar_roots = {saltenv: pillar_roots[saltenv]}
          else:
              return False
  
      for env in pillar_roots:
          for pillar_dir in pillar_roots[env]:
              full_path = os.path.join(pillar_dir, path)
              if __salt__['file.file_exists'](full_path):
                  return True
  
      return False