মডিউল ৩: Reverse Proxy for Laravel, Go, Next.js

        ┌────────┐        ┌────────┐         ┌──────────────┐
Client ─┤ request├──────▶ │ Nginx  │ ──────▶ │ backend app  │
        └────────┘        │ (proxy)│ ◀────── │ (:8080 etc.) │
            ▲             └────────┘         └──────────────┘
            └──── response ───┘

proxy_pass http://127.0.0.1:8080;

 Laravel :  Client ──▶ Nginx ──▶ PHP-FPM socket ──▶ Laravel
 Go API  :  Client ──▶ Nginx ──▶ Go app (:8080)
 Next.js :  Client ──▶ Nginx ──▶ Next.js (:3000)

 Client ──▶ Nginx ──┬─ static file? ──▶ public/ থেকে serve
                    └─ .php / route ──▶ PHP-FPM ──▶ Laravel

server {
    listen 80;
    server_name admin.example.com;
    root /var/www/admin/public;
    index index.php index.html;
 
    location / {
        try_files $uri $uri/ /index.php?$query_string;   # route → index.php
    }
 
    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_pass unix:/run/php/php8.2-fpm.sock;       # PHP execute
    }
}

 Client ──▶ Nginx ──▶ proxy_pass ──▶ Go app (127.0.0.1:8080)

server {
    listen 80;
    server_name api.example.com;
 
    location / {
        proxy_pass http://127.0.0.1:8080;
        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;
    }
}

 Client ──▶ Nginx ──▶ proxy_pass ──▶ Next.js (127.0.0.1:3000)
                       + Upgrade header (websocket/HMR)

server {
    listen 80;
    server_name app.example.com;
 
    location / {
        proxy_pass http://127.0.0.1:3000;
        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;
        proxy_set_header Upgrade           $http_upgrade;     # websocket
        proxy_set_header Connection        "upgrade";
    }
}

 file system থেকে serve করতে হবে?  ──▶ root + try_files
 PHP execute করতে হবে?            ──▶ fastcgi_pass
 already-running app-এ পাঠাতে হবে? ──▶ proxy_pass

 admin.example.com ──▶ Nginx ──▶ Laravel  (PHP-FPM)
 api.example.com   ──▶ Nginx ──▶ Go API   (:8080)
 app.example.com   ──▶ Nginx ──▶ Next.js  (:3000)