我正在尝试在两个docker容器之间设置nginx代理传递。我的前端容器似乎工作正常，但当我试图访问后端时出现502错误。我有两个docker-compose文件：
docker-compose.yml

version: "3.1"

services:
  backend:
    image: backend_image
    container_name: backend_container
  frontend:
    container_name: frontend_container
    image: frontend_image
  proxy:
    container_name: proxy_container
    image: nginx
    restart: unless-stopped
    ports:
      - "8080:80"
    depends_on:
      - website
      - frontend

docker-compose-development.yml

version: "3.1"

services:
  backend:
    container_name: backend_container_development
  frontend:
    build:
      context: ./site/public_html/frontend
      target: runner
    volumes:
      - ./site/public_html/frontend:/app
    command: npm run dev
    ports:
      - "3000:80"
    environment:
      NODE_ENV: development
  proxy:
    volumes:
      - ./nginx/local.conf:/etc/nginx/nginx.conf
      - ./logs:/var/logs

我的nginx local.conf文件：

events {
    worker_connections 1024;
}

http {
    server {
        listen 80 default_server;

        location / {
            proxy_pass http://frontend:3000;
            error_log /var/log/frontend_errors.log;
        }

        location /api {
            proxy_pass http://backend:8000;
            error_log /var/log/backend_errors.log;
        }
    }
}

这是我收到的错误
[error] 29#29: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 192.168.48.1, server: , request: "GET /api HTTP/1.1", upstream: "http://192.168.48.3:8000/api", host: "localhost:8080"
我已经验证了后端和前端容器的IP是192.168.48.3，并且容器分别在localhost：8000和localhost：3000上运行