Keep url in address bar with a proxy reverse on nginx

Question

I have a web application where users can create their page. The web application will generate a URL like this for each page created : https://my-domain.com/page/12345. I would like to give my users the possibility to use their own domain / subdomain instead of this URL on my website by just pointing a cname record to my server.

So I ran some tests with another domain I have on Cloudflare and created the following cname record :

subdomain.domain.com.   1   IN  CNAME   my-web-app-domain.com.

Basically, I want subdomain.domain.com to point to my web app domain so my users can access their page using subdomain.domain.com.

To achieve that on my target web app server that uses nginx, I have created the following block in my nginx config file :

server {
    listen 80;
    server_name subdomain.domain.com;
    
    location / {
        proxy_pass http://my-web-app-domain.com/page/12345;
        proxy_set_header   X-Real-IP $remote_addr;
    }
}

So this basically works but instead of keeping subdomain.domain.com in the address bar, it redirects the user to http://my-web-app-domain.com/page/12345. How can I modify my code so it keeps subdomain.domain.com instead of redirecting?

In case it's useful, my web app uses Laravel and to test if it may be the issue, I have added this into my TrustProxies.php file but it's still the same :

protected $proxies = '*';

score 0 · Answer 1 · answered Jul 19 '22 at 11:15

I think the issue here is that your Laravel application expects HTTP Host header to be my-web-app-domain.com, but it is something else. This mismatch makes the application to redirect to the correct application domain.

Try adding proxy_set_header Host my-web-app-domain.com; to your configuration.

Keep url in address bar with a proxy reverse on nginx

1 Answers1