在不劫持连接的情况下获取本地HTTP服务器的端口

Question

In a http handler is there a way to get the port of the server that received the request without using http.Hijacker to get the TCP connection, if there isn't is there a way to hijack the connection but still use the provided http.ResponseWriter

Answer 1

Get the local address from the request context using http.LocalAddrContextKey.

a, ok := req.Context().Value(http.LocalAddrContextKey).(net.Addr)
if !ok {
    // handle address not found
}

Get the TCP port from the address:

ta, ok := a.(*net.TCPAddr)
if !ok {
    // handle unknown address type
}
port := ta.Port