使用Docker Compose安装FastAPI遇域名解析失败及版本匹配错误的解决方法

问题背景 #

尝试通过Docker Compose部署FastAPI+Angular项目，相关配置如下：

docker-compose.yml配置 #

version: "3.9"

services:
  fastapi_app:
    build:
      context: ./backend
    image: fastapi_app:latest
    ports:
      - target: 8000
        published: 8000
    volumes:
      - type: bind
        source: ./backend/app
        target: /app
    networks:
      - websocket

  angular:
    image: node:18.13.0-alpine
    working_dir: /frontend
    ports:
      - target: 4200
        published: 4200
    volumes:
      - type: bind
        source: ./frontend
        target: /frontend
    networks:
      - websocket
    command: npm start

networks:
  websocket:
    name: websocket
    driver: bridge

后端Dockerfile #

FROM python:3.11
WORKDIR /app
COPY ./requirements.txt /app/requirements.txt
RUN pip install --no-cache-dir --upgrade -r /app/requirements.txt
COPY ./app /app
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]

requirements.txt内容 #

fastapi>=0.89.0
uvicorn[standard]>=0.20.0,<0.21.0

错误信息 #

构建镜像执行pip安装依赖时出现以下错误：

> [4/5] RUN pip install --no-cache-dir --upgrade -r /app/requirements.txt:                                       
11.60 WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7fb48a1ad890>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution')': /simple/fastapi/                   

69.15 ERROR: Could not find a version that satisfies the requirement fastapi>=0.89.0 (from versions: none)
69.15 ERROR: No matching distribution found for fastapi>=0.89.0

解决方案 #

1. 修复Docker构建阶段的网络解析问题 #

错误提示里的Temporary failure in name resolution说明Docker容器在构建时无法解析PyPI域名，可通过两种方式修复：

方式A：给build阶段指定网络

修改docker-compose.yml中fastapi_app的build配置，添加网络参数，让构建过程使用已定义的websocket网络：

services:
  fastapi_app:
    build:
      context: ./backend
      network: websocket  # 添加该行配置
    # 其余配置保持不变

方式B：修改Docker全局DNS配置

编辑Docker守护进程配置文件（通常路径为/etc/docker/daemon.json），添加公共DNS服务器：

{
  "dns": ["8.8.8.8", "114.114.114.114"]
}

修改后重启Docker服务：

sudo systemctl restart docker

2. 切换国内PyPI镜像源加速安装 #

由于网络访问官方PyPI受限，可在pip命令中指定国内镜像源，修改Dockerfile中的RUN命令：

RUN pip install --no-cache-dir --upgrade -i https://pypi.tuna.tsinghua.edu.cn/simple -r /app/requirements.txt

常用国内镜像源还有阿里云https://mirrors.aliyun.com/pypi/simple/、豆瓣https://pypi.douban.com/simple/等。

3. 确认requirements.txt的合法性 #

检查依赖配置是否正确：

• fastapi>=0.89.0为有效稳定版本，确认无拼写错误（如误写为fastpi）
• uvicorn[standard]>=0.20.0,<0.21.0的版本范围合法，无需调整

内容的提问来源于stack exchange，提问作者MikiBelavista