如何配置 Nginx 反向代理 Node.js/Python 应用？

后端应用跑在 3000 端口，想通过域名 80/443 端口访问

解决方案

基本反向代理 + HTTPS 推荐

server {
    listen 80;
    server_name api.example.com;
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;
    server_name api.example.com;

    ssl_certificate /etc/letsencrypt/live/api.example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/api.example.com/privkey.pem;

    location / {
        proxy_pass http://localhost:3000;
        proxy_set_header Host $host;
        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;
    }
}

HTTP 自动跳转 HTTPS，所有请求转发到本地 3000 端口的应用。设置必要的请求头让后端能获取真实客户端信息。

适用场景：单个后端应用，需要 HTTPS

前后端分离部署

server {
    listen 443 ssl http2;
    server_name example.com;
    # SSL 配置省略...

    # 前端静态文件
    location / {
        root /var/www/frontend/dist;
        try_files $uri $uri/ /index.html;
    }

    # API 代理到后端
    location /api/ {
        proxy_pass http://localhost:3000/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }

    # WebSocket
    location /ws/ {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}

同一域名下，/ 走前端静态文件，/api/ 走后端服务，/ws/ 走 WebSocket。避免跨域问题。

适用场景：前后端同域部署，需要 WebSocket