I found this tweet nice for inspiration and also to know what the "competition" looks like.
package main
import (
"io"
"net"
)
func main() {
s, _ := net.Listen("tcp", ":8080")
for {
l, _ := s.Accept()
r, _ := net.Dial("tcp", "localhost:8081")
go io.Copy(l, r)
go io.Copy(r, l)
}
}