🚀 END-TO-END: NGINX REVERSE PROXY TUTORIAL

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✅ 1. What is a Reverse Proxy (Easy Explanation)

A reverse proxy sits in front of your backend app and forwards requests.

Flow:

Client → NGINX → Backend Server (Node/Golang/Python)

NGINX handles:

• Routing

• SSL/TLS

• Load balancing

• Caching

• Security

• Rate limiting

Your backend only handles business logic.

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✅ 2. Example Setup

We assume:

• Backend running at: http://localhost:3000

• NGINX receives requests at: http://your-domain

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📌 3. Install NGINX

Ubuntu / Debian:

sudo apt update
sudo apt install nginx -y
sudo systemctl start nginx
sudo systemctl enable nginx

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📁 4. Create Reverse Proxy Config

Create a new NGINX server block:

sudo nano /etc/nginx/sites-available/myapp

Paste this:

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://127.0.0.1:3000;

        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;
    }
}

Replace example.com with your domain or IP.

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🔌 5. Enable the Reverse Proxy

Enable config:

sudo ln -s /etc/nginx/sites-available/myapp /etc/nginx/sites-enabled/

Remove default:

sudo rm /etc/nginx/sites-enabled/default

Test config:

sudo nginx -t

Reload:

sudo systemctl reload nginx

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🔥 Now your backend is live!

Visit:

👉 http://your-domain
NGINX → Forwards → Backend server

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⚡ 6. Add SSL (HTTPS) Automatically

Install Certbot:

sudo apt install certbot python3-certbot-nginx -y

Run:

sudo certbot --nginx -d example.com

Certbot will:

✔ Install SSL
✔ Configure HTTPS
✔ Redirect HTTP → HTTPS

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📌 7. Optional: Proxy for Specific Paths

Example:

location /api/ {
    proxy_pass http://127.0.0.1:3000/;
}

location /auth/ {
    proxy_pass http://127.0.0.1:4000/;
}

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🧪 8. Optional: Reverse Proxy for WebSocket (Real-Time apps)

Use this if your backend uses WebSocket:

location /ws/ {
    proxy_pass http://127.0.0.1:3000;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
}

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📊 9. Logs for Debugging

Access logs:

tail -f /var/log/nginx/access.log

Error logs:

tail -f /var/log/nginx/error.log

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🛡 10. Bonus: Improve Reverse Proxy Performance

Add to nginx.conf → inside http {}:

proxy_read_timeout 60s;
proxy_connect_timeout 60s;
proxy_send_timeout 60s;

client_max_body_size 20M;

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🎉 Reverse Proxy Setup Completed!

You now have:

✔ NGINX reverse proxy
✔ Backend linked
✔ SSL enabled
✔ Path-based routing
✔ WebSocket support
✔ Optimized configuration

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