Docker化Laravel 7应用无法显示首页，Nginx返回502错误

问题现象 #

• 按教程搭建MySQL、Nginx、PHP容器后，src/public/index.html可正常加载显示
• 清空src目录并创建Laravel应用后，访问返回502 Bad Gateway错误
• Nginx容器内/var/log/nginx目录下的日志文件存在但无内容，容器日志显示连接PHP服务被拒绝

相关配置文件 #

default.conf #

server {
    listen 81;
    index index.php index.html;
    server_name localhost;
    error_log /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;
    root /var/www/html/public;

    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }

    location ~ \.php$ {
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass php:9001;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }
}

docker-compose.yml #

version: '3'

networks:
  laravel:

services:
  nginx:
    image: nginx:stable-alpine
    container_name: nginx-laravel
    ports:
      - "8088:81"
    volumes:
      - ./src:/var/www/html
      - ./nginx/default.conf:/etc/nginx/conf.d/default.conf
    depends_on:
      - php
      - mysql
    networks:
      - laravel

  mysql:
    platform: linux/x86_64
    image: mysql:5.7.34
    container_name: mysql-laravel
    restart: unless-stopped
    tty: true
    ports:
      - "4306:3306"
    volumes:
      - ./mysql:/var/lib/mysql
    environment:
      MYSQL_DATABASE: homestead
      MYSQL_USER: homestead
      MYSQL_PASSWORD: secret
      MYSQL_ROOT_PASSWORD: secret
      SERVICE_TAGS: dev
      SERVICE_NAME: mysql
    networks:
      - laravel

  php:
    build:
      context: .
      dockerfile: Dockerfile
    container_name: php-laravel
    volumes:
      - ./src:/var/www/html
    ports:
      - "9001:9001"
    networks:
      - laravel

Dockerfile #

FROM php:7.2-fpm-alpine

RUN docker-php-ext-install pdo pdo_mysql

Nginx容器关键日志 #

2022-08-25T23:53:58.719467761Z 2022/08/25 23:53:58 [error] 35#35: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 172.20.0.1, server: localhost, request: "GET / HTTP/1.1", upstream: "fastcgi://172.20.0.2:9001", host: "localhost:8088"

错误原因 #

官方php:7.2-fpm-alpine镜像默认监听9000端口，但配置中Nginx尝试连接PHP容器的9001端口，同时Docker Compose将主机9001端口映射到容器9001端口，而PHP-FPM实际未在9001端口提供服务，导致连接被拒绝，触发502错误。

解决方案 #

方案1：修改Nginx配置，指向PHP默认端口 #

修改default.conf中的fastcgi_pass端口为9000：

location ~ \.php$ {
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_pass php:9000; # 替换为9000
    fastcgi_index index.php;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param PATH_INFO $fastcgi_path_info;
}

方案2：修改PHP容器，让FPM监听9001端口 #

若需保留9001端口，修改Dockerfile添加FPM端口配置：

FROM php:7.2-fpm-alpine

RUN docker-php-ext-install pdo pdo_mysql
# 添加以下行，修改FPM监听端口为9001
RUN echo "listen = 9001" >> /usr/local/etc/php-fpm.d/www.conf

重启容器并修复Laravel权限 #

修改完成后，重新构建启动容器：

docker-compose down
docker-compose build php
docker-compose up -d

进入PHP容器，修复Laravel目录权限：

docker exec -it php-laravel chmod -R 775 /var/www/html/storage /var/www/html/bootstrap/cache
docker exec -it php-laravel chown -R www-data:www-data /var/www/html/storage /var/www/html/bootstrap/cache

内容的提问来源于stack exchange，提问作者Geeda