Replace Contents in NGINX

The content of a webpage contains URL or other information need to be replaced, especially when domain name changed in URL.

sub_filter

Use sub_filter module in NGINX to replace content.

For example,

server {
    ```
    location / {
        sub_filter 'www.example.com' 'www.xx.example.com';
        sub_filter_once on;

        proxy_pass  http://www.example.com;
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
        proxy_redirect off;
        proxy_buffering off;
        proxy_set_header        Host            $host;
        proxy_set_header        X-Real-IP       $remote_addr;
        proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
   }
}

Note: Place sub_filter at beginning of the location session

If required, also need to change host to allow server decide which page requested if it is also a NGINX server and displays page depending on the host as well.

proxy_set_header        Host            www.example.com;

References

Module ngx_http_sub_module
http_sub_module / sub_filter of nginx and reverse proxy not working