Docker Compose环境下Nginx与php-fpm连接被拒绝问题求助

访问localhost:8080时Nginx返回502 - Bad Gateway，对应的错误日志如下：

2023/03/10 12:52:54 [error] 31#31: *10 connect() failed (111: Connection refused) while connecting to upstream, client: 172.19.0.1, server: , request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://172.19.0.4:9000", host: "localhost:8080", referrer: "http://localhost:8080/index.php"

相关配置文件 #

NGINX配置文件（default.conf） #

server {
listen 80;
index index.php index.html;
error_log  /var/log/nginx/error.log;
access_log /var/log/nginx/access.log;
root /var/www;
location ~ \.php$ {
    try_files $uri =404;
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_index index.php;
    fastcgi_pass app:9000;
    proxy_set_header X-Forwarded-For $remote_addr;
    include fastcgi_params;
    fastcgi_param REQUEST_METHOD $request_method;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param PATH_INFO $fastcgi_path_info;
}
location / {
    try_files $uri $uri/ /index.php?$query_string;
    gzip_static on;
    proxy_set_header Host $http_host;
}
}

php-fpm应用Dockerfile #

FROM php:7.4-fpm

# Copy composer.lock and composer.json
COPY composer.lock composer.json /var/www/

# Set working directory
WORKDIR /var/www

# Install dependencies
RUN apt-get update && apt-get install -y \
    build-essential \
    libpng-dev \
    libjpeg62-turbo-dev \
    libfreetype6-dev \
    locales \
    zip \
    jpegoptim optipng pngquant gifsicle \
    vim \
    unzip \
    git \
    curl \
    libzip-dev

# Clear cache
RUN apt-get clean && rm -rf /var/lib/apt/lists/*

# Install extensions
RUN docker-php-ext-install pdo_mysql mbstring zip exif pcntl
RUN docker-php-ext-configure gd --with-gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ --with-png-dir=/usr/include/
RUN docker-php-ext-install gd

# Install composer
#RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer

# Add user for laravel application
RUN groupadd -g 1000 www
RUN useradd -u 1000 -ms /bin/bash -g www www

# Copy existing application directory contents
COPY . /var/www

# Copy existing application directory permissions
COPY --chown=www:www . /var/www

# Change current user to www
USER www

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

Docker-compose.yaml #

version: '3'
services:
  #PHP Service
  app:
    build:
      context: .
      dockerfile: dockerfile
    image: php
    container_name: app
    restart: unless-stopped
    tty: true
    environment:
      SERVICE_NAME: app
      SERVICE_TAGS: dev
    working_dir: /var/www
    networks:
      - app-network
    volumes:
      - ./:/var/www
      - ./php/local.ini:/usr/local/etc/php/conf.d/local.ini
    depends_on:
      - webserver

  #Nginx Service
  webserver:
    image: nginx:alpine
    container_name: webserver
    restart: unless-stopped
    tty: true
    ports:
      - "8080:80"
    networks:
      - app-network
    volumes:
      - ./:/var/www
      - ./nginx/conf.d/:/etc/nginx/conf.d/

  #MySQL Service
  db:
    image: mariadb
    container_name: db
    restart: unless-stopped
    tty: true
    ports:
      - "3306:3306"
    environment:
      MYSQL_DATABASE: laravel
      MYSQL_ROOT_PASSWORD: MYSQL_ROOT_PASSWORD
      SERVICE_TAGS: dev
      SERVICE_NAME: mysql
    volumes:
     - dbdata:/var/lib/mysql
     - ./my.cnf:/etc/mysql/my.cnf
    networks:
     - app-network

#Docker Networks
networks:
  app-network:
    driver: bridge

#Volumes
volumes:
 dbdata:
  driver: local

解决方案建议 #

• 修正容器启动依赖顺序：当前app服务依赖webserver启动，但实际应该是Nginx依赖php-fpm服务才能正常转发请求。修改docker-compose.yaml：移除app服务下的depends_on: - webserver，给webserver服务添加depends_on: [app]，确保php-fpm先启动完成后再启动Nginx。
• 确认php-fpm监听端口配置：进入php容器执行docker exec -it app bash，然后用netstat -tulpn | grep 9000检查php-fpm是否监听在0.0.0.0:9000（而非仅127.0.0.1，否则容器间无法通信）。若监听地址不对，检查/usr/local/etc/php-fpm.d/www.conf中的listen参数，修改为listen = 9000或listen = 0.0.0.0:9000。
• 统一文件权限：Nginx Alpine镜像默认运行用户是nginx，php容器运行用户是www（UID 1000）。要么给宿主机项目目录设置权限chown -R 1000:1000 ./，要么在docker-compose.yaml的webserver服务中添加user: "1000:1000"，让Nginx以相同用户运行，避免php无法读取脚本文件。
• 清理重建容器：清理现有容器和缓存，执行docker-compose down -v删除容器和卷，然后docker-compose build --no-cache重新构建镜像，最后docker-compose up -d启动服务。
• 优化Nginx fastcgi配置：在location ~ \.php$块中，proxy_set_header是用于反向代理的配置，fastcgi场景下不需要，删除proxy_set_header X-Forwarded-For $remote_addr;这一行，避免干扰fastcgi通信逻辑。

内容的提问来源于stack exchange，提问作者Luca Pisoni