Golang FindDevice Examples

Example #1

File: nbd.go Project: coreos/torus

func connectNBD(srv *torus.Server, f *block.BlockFile, target string, closer chan bool) error {
	defer f.Close()
	size := f.Size()

	gmd := srv.MDS.GlobalMetadata()

	handle := nbd.Create(f, int64(size), int64(gmd.BlockSize))

	if target == "" {
		t, err := nbd.FindDevice()
		if err != nil {
			return err
		}
		target = t
	}

	_, err := handle.OpenDevice(target)
	if err != nil {
		return err
	}

	go func(n *nbd.NBD) {
		<-closer
		n.Disconnect()
	}(handle)

	err = handle.Serve()
	if err != nil {
		return fmt.Errorf("error from nbd server: %s", err)
	}
	return nil
}

Example #2

File: nbd.go Project: ConfusedReality/server_distributed-storage_torus

func connectNBD(srv *torus.Server, f *block.BlockFile, target string, closer chan bool) error {
	defer f.Close()
	size := f.Size()

	gmd, err := srv.MDS.GlobalMetadata()
	if err != nil {
		return err
	}

	handle := nbd.Create(f, int64(size), int64(gmd.BlockSize))

	if target == "" {
		target, err = nbd.FindDevice()
		if err != nil {
			fmt.Println(err)
			return err
		}
	}

	dev, err := handle.OpenDevice(target)
	if err != nil {
		fmt.Println(err)
		return err
	}
	fmt.Println("Connected to", dev)

	go func(n *nbd.NBD) {
		<-closer
		n.Disconnect()
	}(handle)

	err = handle.Serve()
	if err != nil {
		fmt.Fprintf(os.Stderr, "error from nbd server: %s\n", err)
		os.Exit(1)
	}
	return handle.Close()
}

Example #3

File: flex.go Project: coreos/torus

//{"kubernetes.io/fsType":"ext4","kubernetes.io/readwrite":"rw","volume":"block1"}
func attachAction(cmd *cobra.Command, args []string) {
	if len(args) != 1 {
		onErr(errors.New("unexpected number of arguments"))
	}
	vol := parseJSONArg(args[0])

	dev, err := nbd.FindDevice()
	if err != nil {
		onErr(err)
	}

	sysd := connectSystemd()

	svc := devToUnitName(dev)

	me, err := osext.Executable()
	if err != nil {
		onErr(err)
	}

	cmdList := []string{
		me,
		"-C",
		vol.Etcd,
		"nbd",
		vol.VolumeName,
		dev,
	}
	if vol.WriteLevel != "" {
		_, err := torus.ParseWriteLevel(vol.WriteLevel)
		if err != nil {
			onErr(err)
		}
		cmdList = append(cmdList, []string{"--write-level", vol.WriteLevel}...)
	}
	if vol.WriteCacheSize != "" {
		cmdList = append(cmdList, []string{"--write-cache-size", vol.WriteCacheSize}...)
	}

	ch := make(chan string)

	sysd.ResetFailedUnit(svc)
	_, err = sysd.StartTransientUnit(svc, "fail", []dbus.Property{
		dbus.PropExecStart(cmdList, false),
	}, ch)
	if err != nil {
		onErr(err)
	}
	<-ch
	status := sysd.wait(svc)
	if status == "failed" {
		onErr(errors.New("Couldn't attach"))
	} else if status == "active" {
		writeResponse(Response{
			Status: "Success",
			Device: dev,
		})
	} else {
		onErr(errors.New(status))
	}
	os.Exit(0)
}