nginx.md

NGINX

• A lightweight reverse proxy.
• Suppose you have a server and you are running two web apps on it.
• One on port 8000 and one on 8001.
• Now suppose we have a domain name "example.com".
• We want abc.example.com to get routed to port 8000 of the machine and xyz.example.com to get routed to the 8001 port of the machine.
• For that, we create 1 file for each web app we want to configure at /etc/nginx/sites-enabled.
• The file names could be anything. Let's just name them the same as the sub-domain they represent.

I mostly code in nodejs. So I usually have a web app running on localhost. So the configuration looks like this:

server {
    listen 80; listen [::]:80;
    server_name abc.example.com;  # <-- change this

    location / {
        proxy_pass http://localhost:8000; # <-- And this
 }
}

How to add a site

cd /etc/nginx/sites-enabled
touch site.conf
vim site.conf

# Paste the following inside the site.conf
server {
    listen 80; listen [::]:80;
    server_name a.domain.com;  # <-- change this

    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $http_host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 }
}

How to enforce HTTPS?

if ($scheme != "https") {
    return 301 https://$host$request_uri;
} # managed by Certbot

Mixed content error

We once got mixed content errors after upgrading to SSL. To fix the issue, we simply had to add some headers to the location block.

location / {
  proxy_pass http://localhost:8000;
  proxy_set_header Host $http_host;
  proxy_http_version 1.1;
  proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header X-Forwarded-Proto https;
}