Nginx reverse proxy to nodejs app - domain root location redirects browser back to server IP

I have a client with an existing domain name which cannot be pointed to my server just yet.

So in the meanwhile I’ve added my node app and configuring the reverse proxy. This is what I’ve done:

1. Added domain entries to my local machine’s hosts file: 134.209.53.229 example.com 134.209.53.229 www.example.com

2. on my droplet’s hosts file, I did the same: 134.209.53.229 example.com 134.209.53.229 www.example.com

3. My nginx reverse proxy setup. This is my /etc/nginx/sites-available/default file:

server {
        listen 80 default_server;
        listen [::]:80 default_server;

        root /var/www/html;
        index index.php index.js index.html index.htm index.nginx-debian.html;

        server_name example.com www.example.com;

        location / {
        proxy_pass http://localhost:8000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
        }
}

Now what happens if I visit any subpath, like http://example.com/products, everything works fine.

But, when I visit root http://example.com - contents are loaded fine, but the address in my browser address bar changes to http://134.209.53.229 .

Looking at my network tab, I see that initiator is example.com, but in the request headers host is actually 134.209.53.229 (not example.com).

How can I fix this?

I followed this guide to set up the reverse proxy: https://www.digitalocean.com/community/tutorials/how-to-set-up-a-node-js-application-for-production-on-ubuntu-16-04

The only prerequisite I have not done is SSL - again because I cannot point this domain name to my server yet. I don’t think that should have anything to do with it though.