func writeSubnet(sn ip.IP4Net, mtu int) error { // Write out the first usable IP by incrementing // sn.IP by one sn.IP += 1 dir, _ := path.Split(opts.subnetFile) os.MkdirAll(dir, 0755) f, err := os.Create(opts.subnetFile) if err != nil { return err } defer f.Close() fmt.Fprintf(f, "RUDDER_SUBNET=%s\n", sn) fmt.Fprintf(f, "RUDDER_MTU=%d\n", mtu) return nil }