Nginx Reverse Proxy

Nginx often sits on ports 80 and 443, then serves files or forwards requests to an app running on localhost.

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-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
  }
}

Always test before reload:

sudo nginx -t
sudo systemctl reload nginx

Further Learning

• “Nginx reverse proxy proxy_pass” — proxy basics
• “Nginx serve static files” — static deployment
• “X-Forwarded-For X-Forwarded-Proto” — proxy headers

Nginx Reverse Proxy

Your app probably runs on some internal port (like 3000), but visitors expect to reach it at a normal web address on port 80/443. Nginx sits in front and forwards public traffic to your app running behind it — this is a reverse proxy.

A basic setup

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-Forwarded-For $proxy_add_x_forwarded_for;
  }
}

proxy_pass says “send this request to my app running on port 3000.” The proxy_set_header lines pass along useful info (like the original visitor’s address) that your app would otherwise lose.

Always test before you reload

sudo nginx -t              # check the config is valid FIRST
sudo systemctl reload nginx  # apply it

In one sentence

Nginx acts as a reverse proxy — accepting public web traffic and forwarding it to your app running privately on a port like 3000 — and you should always run nginx -t to validate the config before reloading.

Want to go deeper?

Switch to Expert mode above for serving static files directly and the full forwarding-header setup.