Nginx reverse proxy -- common configuration patterns

Nginx reverse proxy with SSL and WebSocket

upstream backend {
    server 127.0.0.1:3000;
    server 127.0.0.1:3001;  # load balance
    keepalive 64;
}

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

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

    # Proxy
    location / {
        proxy_pass http://backend;
        proxy_http_version 1.1;
        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;
    }

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

    # Static files
    location /static/ {
        root /var/www;
        expires 30d;
        add_header Cache-Control "public, immutable";
    }
}