使用Sequelize与Docker连接MySQL数据库时遭遇连接拒绝错误

错误信息 #

ConnectionRefusedError [SequelizeConnectionRefusedError]: connect ECONNREFUSED 192.168.32.2:3306

当前配置文件 #

docker-compose.yml #

version: '3.9'

services:
  db:
    image: 'mysql'
    ports:
      - '3306:3306'
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: 12345678
      MYSQL_DATABASE: sweeft
      MYSQL_USER: sweeft_user
      MYSQL_PASSWORD: 12345678

  server:
    build: .
    ports:
      - '3000:3000'
    depends_on:
      - db
    environment:
      DB_HOST: db
      DB_USER: sweeft_user
      DB_PASSWORD: 12345678
      DB_NAME: sweeft

Sequelize连接代码 #

import Sequelize from 'sequelize';

const sequelize = new Sequelize('sweeft', 'sweeft_user', 12345678, {
  host: 'db',
  dialect: 'mysql',
});

export default sequelize;

问题原因与解决方法 #

核心原因 #

depends_on仅保证容器启动顺序，无法确保MySQL服务完全初始化完成。Node服务启动时，MySQL可能还在初始化数据库、创建用户，导致连接被拒绝。

解决方案1：添加MySQL健康检查 #

在docker-compose.yml的db服务中配置健康检查，确保MySQL服务就绪后再启动Node服务：

db:
  image: 'mysql'
  ports:
    - '3306:3306'
  restart: always
  environment:
    MYSQL_ROOT_PASSWORD: 12345678
    MYSQL_DATABASE: sweeft
    MYSQL_USER: sweeft_user
    MYSQL_PASSWORD: 12345678
  healthcheck:
    test: ["CMD", "mysqladmin", "ping", "-h", "localhost", "-u", "root", "-p12345678"]
    interval: 5s
    timeout: 5s
    retries: 5

server:
  build: .
  ports:
    - '3000:3000'
  depends_on:
    db:
      condition: service_healthy
  environment:
    DB_HOST: db
    DB_USER: sweeft_user
    DB_PASSWORD: 12345678
    DB_NAME: sweeft

解决方案2：在代码中添加连接重试逻辑 #

修改Sequelize连接代码，添加自动重试机制，直到连接成功：

import Sequelize from 'sequelize';

const sequelize = new Sequelize('sweeft', 'sweeft_user', 12345678, {
  host: 'db',
  dialect: 'mysql',
});

async function initDBConnection() {
  try {
    await sequelize.authenticate();
    console.log('数据库连接成功');
    // 后续初始化模型等操作
  } catch (error) {
    console.error('连接失败，10秒后重试:', error.message);
    setTimeout(initDBConnection, 10000);
  }
}

initDBConnection();

export default sequelize;

解决方案3：使用等待脚本 #

在Node服务的Dockerfile中引入等待脚本，等待MySQL端口就绪后再启动服务：

1. 将wait-for-it.sh脚本下载到项目根目录
2. 修改Dockerfile：

FROM node:18-alpine

WORKDIR /app

COPY package*.json ./
RUN npm install

COPY . .
COPY wait-for-it.sh /usr/local/bin/
RUN chmod +x /usr/local/bin/wait-for-it.sh

CMD ["wait-for-it.sh", "db:3306", "--", "node", "your-entry-file.js"]

额外检查项 #

• 确认Sequelize连接参数（数据库名、用户名、密码）与docker-compose环境变量完全一致
• 进入Node容器执行ping db，验证内部网络是否能解析MySQL服务主机名

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