Retrieving User IP Address in a Golang App Engine Web Application

To successfully integrate reCAPTCHA into your GAE Golang web application, obtaining the user's IP address is essential. Here's a solution to fetch this information from a form post.

Utilize the net.SplitHostPort function:

ip, _, _ := net.SplitHostPort(r.RemoteAddr)

In this code, r represents the Request object from the HTTP request. net.SplitHostPort separates the host and port information from the r.RemoteAddr value, which stores the user's IP address. Assigning the result to variables ip, hostname, and port allows you to access the user's IP address in the ip variable.