package freeport import ( "net" ) // Ask the kernel for a free open port that is ready to use func GetPort() int { addr, err := net.ResolveTCPAddr("tcp", "localhost:0") if err != nil { panic(err) } l, err := net.ListenTCP("tcp", addr) if err != nil { panic(err) } defer l.Close() return l.Addr().(*net.TCPAddr).Port }