Github Actions+Docker Compose测试MySQL连接失败及环境变量配置求助

一、数据库连接失败的核心解决方案 #

1. 等待MySQL容器完全就绪 #

docker-compose up -d执行后，MySQL容器需要时间完成初始化（创建数据库、加载权限等），直接运行测试会因数据库未就绪导致连接失败。在CI环境中必须添加等待步骤，可通过以下方式实现：

- name: Wait for MySQL to be ready
  run: |
    while ! nc -z localhost 3306; do
      echo "Waiting for MySQL on port 3306..."
      sleep 2
    done

注意：需确保你的docker-compose.yml中MySQL服务已映射3306端口到主机，配置示例：ports: "3306:3306"

2. 对齐测试代码的数据库连接配置 #

如果测试在Github Runner主机上执行（而非容器内），测试代码中的数据库地址需设为localhost；若测试在容器内执行，需使用Docker Compose中MySQL服务的名称作为主机名（比如mysql，取决于你的docker-compose.yml服务定义）。同时要保证用户名、密码、数据库名与容器配置完全一致。

二、Github环境中配置环境变量的方法 #

本地.env中的敏感信息（如MySQL密码）需通过Github Secrets安全传递：

1. 添加仓库Secrets #

1. 进入你的Github仓库 → Settings → Secrets and variables → Actions
2. 点击New repository secret，依次添加所需机密，例如：
   • DB_USER：MySQL用户名
   • DB_PASSWORD：MySQL密码
   • DB_NAME：测试用数据库名称

2. 在Actions工作流中调用Secrets #

方式一：传递给Docker Compose

如果你的docker-compose.yml通过环境变量配置MySQL服务，可在启动时直接注入Secrets：

- name: Run the docker compose
  working-directory: ./project
  run: docker-compose up -d
  env:
    DB_USER: ${{ secrets.DB_USER }}
    DB_PASSWORD: ${{ secrets.DB_PASSWORD }}
    DB_NAME: ${{ secrets.DB_NAME }}

对应的docker-compose.yml服务配置示例：

services:
  mysql:
    environment:
      MYSQL_ROOT_PASSWORD: ${DB_PASSWORD}
      MYSQL_DATABASE: ${DB_NAME}
      MYSQL_USER: ${DB_USER}
      MYSQL_PASSWORD: ${DB_PASSWORD}

方式二：传递给测试步骤

如果测试代码直接读取环境变量，在测试步骤中注入Secrets：

- name: run servers test
  working-directory: ./project/server
  run: npm test
  env:
    DB_HOST: localhost
    DB_USER: ${{ secrets.DB_USER }}
    DB_PASSWORD: ${{ secrets.DB_PASSWORD }}
    DB_NAME: ${{ secrets.DB_NAME }}

修改后的完整Github Actions配置 #

name: Docker Image CI

on:
  push:
    branches: [ "main" ]
  pull_request:
    branches: [ "main" ]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v3
    
    - name: Build the Docker images 
      working-directory: ./project
      run: docker-compose build
    
    - name: Run the docker compose
      working-directory: ./project
      run: docker-compose up -d
      env:
        DB_USER: ${{ secrets.DB_USER }}
        DB_PASSWORD: ${{ secrets.DB_PASSWORD }}
        DB_NAME: ${{ secrets.DB_NAME }}
    
    - name: Wait for MySQL to be ready
      run: |
        while ! nc -z localhost 3306; do
          echo "Waiting for MySQL on port 3306..."
          sleep 2
        done
    
    - name: install server dependencies
      working-directory: ./project/server
      run: npm ci
    
    - name: run servers test
      working-directory: ./project/server
      run: npm test
      env:
        DB_HOST: localhost
        DB_USER: ${{ secrets.DB_USER }}
        DB_PASSWORD: ${{ secrets.DB_PASSWORD }}
        DB_NAME: ${{ secrets.DB_NAME }}
    
    - name: finish docker down
      working-directory: ./project
      run: docker-compose down

额外排查点 #

• 查看MySQL容器日志：在失败步骤前添加docker-compose logs mysql命令，排查容器启动报错
• 检查端口占用：添加netstat -tulpn | grep 3306步骤，确认Runner主机的3306端口未被占用

内容的提问来源于stack exchange，提问作者Romano