There are a few of these but many of them require javascript. To avoid requiring javascript I prefer to add this to the nginx configuration on any of my VM's:

    location /ip/ { gzip_static off; ssi on; index index.html; ssi_silent_errors on; }

Then in /ip/index.html I just add:

    REMOTE_ADDR: <!--#echo var="REMOTE_ADDR" -->

If that nginx node is behind a load balancer then a different variable than REMOTE_ADDR may be required. By not requiring javascript, one can use curl or any other command line https tool to get their IP.

This is probably the most simple way for you to get my IP....