M1芯片MacOS下Docker Compose host网络模式失效问题咨询

环境信息 #

• Docker Compose版本：v2.23.3
• Docker(podman)版本：

  Client:       Podman Engine
  Version:      4.9.3
  API Version:  4.9.3
  Go Version:   go1.21.7
  Git Commit:   8d2b55ddde1bc81f43d018dfc1ac027c06b26a7f
  Built:        Tue Feb 13 14:55:17 2024
  OS/Arch:      darwin/arm64
  
  Server:       Podman Engine
  Version:      4.9.0
  API Version:  4.9.0
  Go Version:   go1.21.6
  Built:        Wed Jan 24 05:07:09 2024
  OS/Arch:      linux/arm64
  

• 操作系统：MacOS 14.3.1 (23D60)
• 芯片：M1

场景与配置 #

有一个名为app的服务，预期监听1997端口接收主机消息。文件夹结构：

tree .
.
├── Dockerfile
├── app
│   ├── app.py
│   ├── received.txt
│   └── send.py
└── docker-compose.yaml

各文件内容 #

Dockerfile

FROM python:3.9-slim

# Set the working directory in the container
WORKDIR /app

# Command to run the application
CMD sh -c 'pwd && ls && exec python app.py'

app.py

import socket

def write_to_file(message):
    with open("/app/received.txt", "a") as f:  # Use mode 'a' to append to the file
        f.write(message + "\n")  # Write the message followed by a newline

def start_server(host='0.0.0.0', port=1997):
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.bind((host, port))
        s.listen()
        print(f"Listening on {host}:{port}")
        while True:
            conn, addr = s.accept()
            with conn:
                print(f"Connected by {addr}")
                while True:
                    data = conn.recv(1024)
                    if not data:
                        break
                    message = data.decode('utf-8')
                    write_to_file(message)
                    if message.strip().lower() == "bye":
                        print("Received 'bye', shutting down the server.")
                        return  # Exit the function and terminate the server

if __name__ == "__main__":
    start_server()

send.py

import socket
import sys

def send_message(host, port, message):
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.connect((host, port))
        s.sendall(message.encode('utf-8'))
        # If you want to wait for a response, uncomment the next line
        # data = s.recv(1024)
    print(f"Message sent: {message}")

if __name__ == "__main__":
    if len(sys.argv) > 1:
        message = ' '.join(sys.argv[1:])  # Join all arguments into a single message, separated by spaces
        send_message('localhost', 1997, message)
    else:
        print("Usage: python send_message.py <message>")

初始docker-compose.yaml

version: '3.8'
services:
  app:
    build:
      context: .
      network: host
    volumes:
      - ./app:/app

问题现象 #

启动服务后，本地执行python3 ./app/send.py hello hello gello触发连接拒绝错误：

python3 ./app/send.py hello hello gello
Traceback (most recent call last):
  File "/~~~/draft/./app/send.py", line 15, in <module>
    send_message('localhost', 1997, message)
  File "/~~~/draft/./app/send.py", line 6, in send_message
    s.connect((host, port))
ConnectionRefusedError: [Errno 61] Connection refused

但在容器内部执行相同命令可正常工作：

docker exec -it draft-app-1  python /app/send.py jillo 
Message sent: jillo

改用network_mode: "host"配置后，问题依旧存在。

解决方法 #

M1 Mac上的Podman基于虚拟机运行，network_mode: host仅作用于虚拟机内部，无法直接让Mac主机访问容器端口。提供两种解决方案：

方案1：使用端口映射（推荐） #

修改docker-compose.yaml，添加端口映射规则，将容器1997端口映射到主机同端口：

version: '3.8'
services:
  app:
    build: .
    ports:
      - "1997:1997"
    volumes:
      - ./app:/app

修改后重启服务，本地执行send.py即可正常连接。

方案2：连接Podman虚拟机IP #

若必须使用host网络，先获取Podman虚拟机的IP地址：

podman machine inspect --format '{{.IPAddress}}'

将send.py中的localhost替换为该IP，或执行命令时指定对应主机地址即可。

内容的提问来源于stack exchange，提问作者IsaIkari