How to Configure Nginx Reverse Proxy for Multiple Apps

What Is a Reverse Proxy?

A reverse proxy sits in front of your application servers, forwarding client requests to the appropriate backend. Nginx is the most popular choice for this role.

Basic Reverse Proxy

server {
    listen 80;
    server_name app.example.com;

    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;
    }
}

Multiple Apps on One Server

# Frontend app
server {
    listen 80;
    server_name www.example.com;

    location / {
        proxy_pass http://localhost:3000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

# API backend
server {
    listen 80;
    server_name api.example.com;

    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

# Admin panel
server {
    listen 80;
    server_name admin.example.com;

    location / {
        proxy_pass http://localhost:5000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

WebSocket Support

location /ws {
    proxy_pass http://localhost:3000;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_set_header Host $host;
    proxy_read_timeout 86400;
}

Load Balancing

upstream backend {
    server 127.0.0.1:3001;
    server 127.0.0.1:3002;
    server 127.0.0.1:3003;
}

server {
    listen 80;
    server_name app.example.com;

    location / {
        proxy_pass http://backend;
    }
}

SSL Termination

# Install Certbot
sudo certbot --nginx -d app.example.com

Certbot automatically configures SSL for your reverse proxy sites.