Docker中运行Locust遇OSError: [Errno 97]地址族不支持协议问题

问题背景 #

在Docker 23.0.3中运行Locust 2.15.1时，当WebUI绑定0.0.0.0:8089时触发地址族不支持的错误，但Nginx容器绑定0.0.0.0:80可正常运行。容器内执行ip r l显示路由状态：

172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown

错误日志 #

[2023-04-08 02:12:15,725] 044913c8d54a/INFO/locust.main: Starting web interface at http://0.0.0.0:8089 (accepting connections from all network interfaces)
[2023-04-08 02:12:15,742] 044913c8d54a/INFO/locust.main: Starting Locust 2.15.1
Traceback (most recent call last):
  File "src/gevent/greenlet.py", line 908, in gevent._gevent_cgreenlet.Greenlet.run
  File "/opt/venv/lib/python3.10/site-packages/locust/web.py", line 478, in start_server
    self.server.serve_forever()
  File "/opt/venv/lib/python3.10/site-packages/gevent/baseserver.py", line 398, in serve_forever
    self.start()
  File "/opt/venv/lib/python3.10/site-packages/gevent/baseserver.py", line 336, in start
    self.init_socket()
  File "/opt/venv/lib/python3.10/site-packages/gevent/pywsgi.py", line 1545, in init_socket
    StreamServer.init_socket(self)
  File "/opt/venv/lib/python3.10/site-packages/gevent/server.py", line 180, in init_socket
    self.socket = self.get_listener(self.address, self.backlog, self.family)
  File "/opt/venv/lib/python3.10/site-packages/gevent/server.py", line 192, in get_listener
    return _tcp_listener(address, backlog=backlog, reuse_addr=cls.reuse_addr, family=family)
  File "/opt/venv/lib/python3.10/site-packages/gevent/server.py", line 284, in _tcp_listener
    sock = GeventSocket(family=family)
  File "/opt/venv/lib/python3.10/site-packages/gevent/_socket3.py", line 133, in __init__
    self._sock = self._gevent_sock_class(family, type, proto, fileno)
OSError: [Errno 97] Address family not supported by protocol
2023-04-08T02:12:15Z <Greenlet at 0x7fd349243c40: <bound method WebUI.start_server of <locust.web.WebUI object at 0x7fd34915e410>>> failed with OSError

问题分析 #

这个错误的核心原因是Locust依赖的gevent库在处理0.0.0.0时，默认尝试同时创建IPv4和IPv6套接字，但容器环境未启用或支持IPv6，导致IPv6套接字创建失败抛出Errno 97。

Nginx容器能正常运行是因为其默认仅监听IPv4，或对地址族的处理逻辑与gevent不同，不会强制尝试IPv6监听。而docker0网桥的linkdown状态可能加剧了网络栈异常，但不是直接触发错误的原因。

解决方法 #

• 强制Locust仅监听IPv4：启动Locust时添加环境变量禁用IPv6支持，或显式指定监听配置：

  # 容器内启动命令
  GEVENT_SUPPORT_IPV6=0 locust -f your_locustfile.py --web-host=0.0.0.0 --web-port=8089
  

  或在Docker run命令中注入环境变量：

  docker run -e GEVENT_SUPPORT_IPV6=0 -p 8089:8089 your-locust-image
  

• 禁用容器IPv6：创建容器时通过sysctl参数强制关闭IPv6：

  docker run --sysctl net.ipv6.conf.all.disable_ipv6=1 -p 8089:8089 your-locust-image
  

• 修复Docker网桥状态：重启Docker服务恢复docker0网桥的正常状态：

  systemctl restart docker
  

  之后重新创建Locust容器。

结论 #

该问题并非Docker本身或Locust核心功能的问题，而是gevent库与容器网络环境的兼容性问题，通过限制IPv4监听或调整容器网络配置即可解决。

内容的提问来源于stack exchange，提问作者Vivek Raut