code: def is_host(s: str) -> bool:
      """
      >>> is_host("localhost")
      True
      >>> is_host("localhost:5000")
      True
      >>> is_host("ghcr.io")
      True
      >>> is_host("127.0.0.1")
      True
      >>> is_host("dstackai")
      False
      """
      return s == "localhost" or ":" in s or "." in s
  
file_path: dstack/src/dstack/_internal/server/services/docker.py
imports: from dataclasses import dataclass
  from enum import Enum
  from typing import Optional
  import requests
label_desc: Use image node_id 3 for calling a global function with example usage: is_host(s) and returns: unknown