Docker部署Laravel多租户应用遭遇502 Bad Gateway错误求助

问题背景 #

配置了包含PHP、Nginx、MySQL和Redis的Docker环境用于运行Laravel多租户应用，但执行docker-compose up时出现502 Bad Gateway错误，相关配置详情如下：

PHP服务Dockerfile #

# Use the official PHP image as the base image with PHP 8.2
FROM php:8.2-fpm

# Set the working directory in the container
WORKDIR /var/www/html

# Copy composer.lock and composer.json to install dependencies
COPY composer.lock composer.json /var/www/html/

# Install Composer (PHP dependency manager)
RUN apt-get update && apt-get install -y \
    git \
    zip \
    unzip \
    libfreetype6-dev \
    libjpeg62-turbo-dev \
    libpng-dev \
    zlib1g-dev \
    && docker-php-ext-configure gd --with-freetype --with-jpeg \
    && docker-php-ext-install -j$(nproc) gd \
    && docker-php-ext-install pdo_mysql \
    && pecl install redis \
    && docker-php-ext-enable redis \
    && curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
# Copy the Laravel application files to the working directory in the container
COPY . /var/www/html

# Install dependencies
RUN composer install


# Expose port 9000 and start php-fpm server
EXPOSE 9001
CMD ["php-fpm"]

Docker Compose文件（docker-compose.yml） #

version: '3'

services:
    nginx:
        container_name: nginx_container
        image: nginx:latest
        ports:
            - "80:80"
        volumes:
            - ./nginx/default.conf:/etc/nginx/conf.d/default.conf
        depends_on:
            - php
        networks:
            - app-network

    php:
        container_name: php_container
        build:
            context: .
            dockerfile: Dockerfile
        volumes:
            - .:/var/www/html
        ports:
            - "9001:9000"
        depends_on:
            - mysql
            - redis
        networks:
            - app-network

    mysql:
        container_name: mysql_container
        image: mysql:5.7
        platform: linux/amd64
        restart: always
        environment:
            MYSQL_DATABASE: zmenu
            MYSQL_USER: user
            MYSQL_PASSWORD: password
            MYSQL_ROOT_PASSWORD: root_password
        volumes:
            - mysql_data:/var/lib/mysql
        networks:
            - app-network

    redis:
        container_name: redis_container
        image: redis:latest
        ports:
            - "6379:6379"
        networks:
            - app-network

networks:
    app-network:
        driver: bridge
        external: true

volumes:
    mysql_data:

Nginx配置（nginx/default.conf） #

server {
    listen 80 default_server;
    server_name ~^(?<subdomain>.+)\.zmenu\.test$;

    location / {
        proxy_pass http://php:9001;
        proxy_set_header Host $subdomain.zmenu.test;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

排查与解决建议 #

1. 修正Nginx与PHP-FPM的通信逻辑 #

PHP-FPM使用FastCGI协议而非HTTP协议，当前Nginx配置用proxy_pass是错误的，需改为fastcgi_pass，同时容器间通信使用PHP容器内部的9000端口（而非主机映射的9001），还要添加Laravel必要的路由转发规则：

修正后的nginx/default.conf：

server {
    listen 80 default_server;
    server_name ~^(?<subdomain>.+)\.zmenu\.test$;

    # 指定Laravel的public目录为根目录
    root /var/www/html/public;
    index index.php index.html index.htm;

    # 处理静态文件与Laravel路由
    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }

    # 处理PHP请求
    location ~ \.php$ {
        fastcgi_pass php:9000;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        include fastcgi_params;
        # 传递子域名信息给Laravel
        fastcgi_param HTTP_HOST $subdomain.zmenu.test;
    }
}

2. 修正PHP容器的端口暴露配置 #

PHP-FPM默认在容器内部监听9000端口，Dockerfile中EXPOSE 9001是错误的，需改为暴露内部实际运行的端口：

修改Dockerfile末尾：

# Expose port 9000 and start php-fpm server
EXPOSE 9000
CMD ["php-fpm"]

3. 检查PHP容器的运行状态与权限 #

• 查看PHP容器日志，确认PHP-FPM是否正常启动：

  docker logs php_container
  

• 确保Laravel的storage和bootstrap/cache目录权限正确，在Dockerfile中添加权限配置：

  # 添加到composer install之后
  RUN chown -R www-data:www-data /var/www/html/storage /var/www/html/bootstrap/cache
  RUN chmod -R 775 /var/www/html/storage /var/www/html/bootstrap/cache
  

4. 验证Docker网络连通性 #

• 检查外部网络app-network是否存在：

  docker network ls
  

  如果不存在，先创建网络：

  docker network create app-network
  

• 进入Nginx容器测试与PHP容器的连通性：

  docker exec -it nginx_container ping php
  

  若无法连通，检查compose文件中所有服务的networks配置是否统一为app-network。

5. 确认Laravel环境配置 #

在项目根目录的.env文件中配置正确的数据库和Redis连接信息（使用容器名称作为主机名）：

APP_URL=http://your-subdomain.zmenu.test

DB_CONNECTION=mysql
DB_HOST=mysql
DB_PORT=3306
DB_DATABASE=zmenu
DB_USERNAME=user
DB_PASSWORD=password

REDIS_HOST=redis
REDIS_PORT=6379

内容的提问来源于stack exchange，提问作者rabih mh