Docker环境下Laravel出现SQLSTATE[HY000][2002]连接拒绝错误求助

首次使用Docker搭建Laravel开发环境，配置了Dockerfile、docker-compose.yaml及.env文件，但执行php artisan migrate时出现SQLSTATE[HY000] [2002] Connection refused错误，尝试相关方案仍未解决，以下是配置文件及错误详情，附排查与修正方法：

相关配置文件 #

Dockerfile #

FROM php:8-fpm

COPY . /app
WORKDIR /app

COPY composer.lock composer.json ./
RUN apt-get update -y && apt-get install -y sendmail libpng-dev

RUN apt-get update && apt-get install -y \
    build-essential \
    curl

RUN curl -sSL https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions -o - | sh -s \
      gd \
      zip 
RUN docker-php-ext-install mysqli pdo pdo_mysql
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
RUN composer update
RUN composer install

docker-compose.yaml #

version: '3.9'
name: caas-portal
services:
      
  front:
    build:
      context: ./webapp
      target: builder
    ports:
      - 4200:4200
    volumes:
      - ./webapp:/project
      - /project/node_modules

  mysql:
    container_name: mysql
    image: mysql:latest
    environment:
      - MYSQL_ROOT_PASSWORD=password
      - MYSQL_DATABASE=db
    ports:
      - 3307:3306/tcp
    networks:
      - laravel

  elasticsearch:
    container_name: elasticsearch
    image: docker.elastic.co/elasticsearch/elasticsearch:7.17.7
    environment:
      - discovery.type=single-node
    ports:
      - 9200:9200/tcp
      - 9300:9300/tcp
    volumes:
        - 'elasticsearch:/usr/share/elasticsearch/data'
    networks:
      - laravel

  app:
    container_name: back
    build: .
    ports:
      - 8000:80
    networks:
      - laravel
      
networks:
  laravel:
    driver: bridge

volumes:
    elasticsearch:
        driver: local

.env相关配置 #

DB_CONNECTION=mysql
DB_HOST=mysql
DB_PORT=3307
DB_DATABASE=db
DB_USERNAME=root
DB_PASSWORD=password

错误信息 #

执行docker exec -it <container> sh进入容器后运行php artisan migrate，报错：

SQLSTATE[HY000] [2002] Connection refused (SQL: select * from information_schema.tables where table_schema = db and table_name = migrations and table_type = 'BASE TABLE')

排查与修正方法 #

1. 修正.env中的数据库端口 #

Docker容器间通信使用容器内部端口，而非宿主机映射的端口。你的MySQL容器内部端口是3306，因此.env里的DB_PORT需改为3306：

DB_PORT=3306

2. 确保MySQL容器完全初始化后再执行migrate #

MySQL容器启动需要时间完成初始化，直接执行migrate会因服务未就绪导致连接拒绝。两种解决方式：

• 手动等待：启动容器后等待1-2分钟再执行migrate命令
• 配置健康检查自动等待：修改docker-compose.yaml，给MySQL添加健康检查，让app服务等待MySQL就绪后再启动

  # mysql服务添加健康检查
  mysql:
    container_name: mysql
    image: mysql:latest
    environment:
      - MYSQL_ROOT_PASSWORD=password
      - MYSQL_DATABASE=db
    ports:
      - 3307:3306/tcp
    networks:
      - laravel
    healthcheck:
      test: ["CMD", "mysqladmin", "ping", "-h", "localhost", "-u", "root", "-ppassword"]
      timeout: 20s
      retries: 10
  
  # app服务添加依赖等待
  app:
    container_name: back
    build: .
    ports:
      - 8000:80
    networks:
      - laravel
    depends_on:
      mysql:
        condition: service_healthy
  

3. 优化Dockerfile构建顺序（可选，但提升开发效率） #

当前Dockerfile先复制整个项目目录，会导致代码修改后需重新安装依赖。调整顺序，先处理依赖再复制代码，利用Docker缓存加速构建：

FROM php:8-fpm

WORKDIR /app

# 先复制composer文件，缓存依赖安装层
COPY composer.lock composer.json ./
RUN apt-get update -y && apt-get install -y sendmail libpng-dev build-essential curl

RUN curl -sSL https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions -o - | sh -s \
      gd \
      zip 
RUN docker-php-ext-install mysqli pdo pdo_mysql
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
RUN composer install --no-dev # 开发环境可移除--no-dev参数

# 最后复制项目代码
COPY . /app

4. 验证容器间网络连通性 #

进入app容器，测试与MySQL容器的网络连通：

docker exec -it back ping mysql

若ping不通，执行docker-compose down -v清理旧容器和网络，再重新启动：docker-compose up -d

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