package constants import ( "fmt" "net" "os" "strings" ) func getIP() string { host, _ := os.Hostname() addrs, _ := net.LookupIP(host) return addrs[0].String() } var ServerAddr string var MyIP string func init() { var exist bool ServerAddr, exist = os.LookupEnv("SERVER_ADDR") if !exist { fmt.Println("Please set SERVER_ADDR as environment variable") } MyIP = getIP() idx := strings.LastIndex(MyIP, ".") ServerAddr = MyIP[:idx+1] + "1" fmt.Println(ServerAddr) }