This repo contains an http application that will reflect back what you send to it.
Set it up on a server and visit the page.
http://your.domainname.com/ - This will return your ip address
http://your.domainname.com/all - This will return all details of the request made.
If you ask for /all then you can also add ?o=json or ?o=xml to see the output in the requested format.
Simply use go get to download the code:
$ go get github.com/gombadi/http-reflector
If running in Azure Websites the it will pick up the listening port info or run it using ./reflector -p <8880>
If you then connect to it with a browser you will see the request details that were sent through to the server.