Cinder Volume Plugin

pkg/volume/cinder/cinder_util.go

@@ -0,0 +1,212 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cinder
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"strings"
+	"time"
+
+	"github.com/golang/glog"
+	"k8s.io/kubernetes/pkg/cloudprovider/providers/openstack"
+	"k8s.io/kubernetes/pkg/util/exec"
+	"k8s.io/kubernetes/pkg/util/mount"
+)
+
+type CinderDiskUtil struct{}
+
+// Attaches a disk specified by a volume.CinderPersistenDisk to the current kubelet.
+// Mounts the disk to it's global path.
+func (util *CinderDiskUtil) AttachDisk(b *cinderVolumeBuilder, globalPDPath string) error {
+	options := []string{}
+	if b.readOnly {
+		options = append(options, "ro")
+	}
+	cloud := b.plugin.host.GetCloudProvider()
+	if cloud == nil {
+		glog.Errorf("Cloud provider not initialized properly")
+		return errors.New("Cloud provider not initialized properly")
+	}
+	diskid, err := cloud.(*openstack.OpenStack).AttachDisk(b.pdName)
+	if err != nil {
+		return err
+	}
+
+	var devicePath string
+	numTries := 0
+	for {
+		devicePath = makeDevicePath(diskid)
+		// probe the attached vol so that symlink in /dev/disk/by-id is created
+		probeAttachedVolume()
+
+		_, err := os.Stat(devicePath)
+		if err == nil {
+			break
+		}
+		if err != nil && !os.IsNotExist(err) {
+			return err
+		}
+		numTries++
+		if numTries == 10 {
+			return errors.New("Could not attach disk: Timeout after 60s")
+		}
+		time.Sleep(time.Second * 6)
+	}
+
+	notmnt, err := b.mounter.IsLikelyNotMountPoint(globalPDPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			if err := os.MkdirAll(globalPDPath, 0750); err != nil {
+				return err
+			}
+			notmnt = true
+		} else {
+			return err
+		}
+	}
+	if notmnt {
+		err = b.blockDeviceMounter.Mount(devicePath, globalPDPath, b.fsType, options)
+		if err != nil {
+			os.Remove(globalPDPath)
+			return err
+		}
+		glog.V(2).Infof("Safe mount successful: %q\n", devicePath)
+	}
+	return nil
+}
+
+func makeDevicePath(diskid string) string {
+	files, _ := ioutil.ReadDir("/dev/disk/by-id/")
+	for _, f := range files {
+		if strings.Contains(f.Name(), "virtio-") {
+			devid_prefix := f.Name()[len("virtio-"):len(f.Name())]
+			if strings.Contains(diskid, devid_prefix) {
+				glog.V(4).Infof("Found disk attached as %q; full devicepath: %s\n", f.Name(), path.Join("/dev/disk/by-id/", f.Name()))
+				return path.Join("/dev/disk/by-id/", f.Name())
+			}
+		}
+	}
+	glog.Warningf("Failed to find device for the diskid: %q\n", diskid)
+	return ""
+}
+
+// Unmounts the device and detaches the disk from the kubelet's host machine.
+func (util *CinderDiskUtil) DetachDisk(cd *cinderVolumeCleaner) error {
+	globalPDPath := makeGlobalPDName(cd.plugin.host, cd.pdName)
+	if err := cd.mounter.Unmount(globalPDPath); err != nil {
+		return err
+	}
+	if err := os.Remove(globalPDPath); err != nil {
+		return err
+	}
+	glog.V(2).Infof("Successfully unmounted main device: %s\n", globalPDPath)
+
+	cloud := cd.plugin.host.GetCloudProvider()
+	if cloud == nil {
+		glog.Errorf("Cloud provider not initialized properly")
+		return errors.New("Cloud provider not initialized properly")
+	}
+
+	if err := cloud.(*openstack.OpenStack).DetachDisk(cd.pdName); err != nil {
+		return err
+	}
+	glog.V(2).Infof("Successfully detached cinder volume %s", cd.pdName)
+	return nil
+}
+
+type cinderSafeFormatAndMount struct {
+	mount.Interface
+	runner exec.Interface
+}
+
+/*
+The functions below depend on the following executables; This will have to be ported to more generic implementations
+/bin/lsblk
+/sbin/mkfs.ext3 or /sbin/mkfs.ext4
+/usr/bin/udevadm
+*/
+func (diskmounter *cinderSafeFormatAndMount) Mount(device string, target string, fstype string, options []string) error {
+	fmtRequired, err := isFormatRequired(device, fstype, diskmounter)
+	if err != nil {
+		glog.Warningf("Failed to determine if formating is required: %v\n", err)
+		//return err
+	}
+	if fmtRequired {
+		glog.V(2).Infof("Formatting of the vol required")
+		if _, err := formatVolume(device, fstype, diskmounter); err != nil {
+			glog.Warningf("Failed to format volume: %v\n", err)
+			return err
+		}
+	}
+	return diskmounter.Interface.Mount(device, target, fstype, options)
+}
+
+func isFormatRequired(devicePath string, fstype string, exec *cinderSafeFormatAndMount) (bool, error) {
+	args := []string{"-f", devicePath}
+	glog.V(4).Infof("exec-ing: /bin/lsblk %v\n", args)
+	cmd := exec.runner.Command("/bin/lsblk", args...)
+	dataOut, err := cmd.CombinedOutput()
+	if err != nil {
+		glog.Warningf("error running /bin/lsblk\n%s", string(dataOut))
+		return false, err
+	}
+	if len(string(dataOut)) > 0 {
+		if strings.Contains(string(dataOut), fstype) {
+			return false, nil
+		} else {
+			return true, nil
+		}
+	} else {
+		glog.Warningf("Failed to get any response from /bin/lsblk")
+		return false, errors.New("Failed to get reponse from /bin/lsblk")
+	}
+	glog.Warningf("Unknown error occured executing /bin/lsblk")
+	return false, errors.New("Unknown error occured executing /bin/lsblk")
+}
+
+func formatVolume(devicePath string, fstype string, exec *cinderSafeFormatAndMount) (bool, error) {
+	if "ext4" != fstype && "ext3" != fstype {
+		glog.Warningf("Unsupported format type: %q\n", fstype)
+		return false, errors.New(fmt.Sprint("Unsupported format type: %q\n", fstype))
+	}
+	args := []string{devicePath}
+	cmd := exec.runner.Command(fmt.Sprintf("/sbin/mkfs.%s", fstype), args...)
+	dataOut, err := cmd.CombinedOutput()
+	if err != nil {
+		glog.Warningf("error running /sbin/mkfs for fstype: %q \n%s", fstype, string(dataOut))
+		return false, err
+	}
+	glog.V(2).Infof("Successfully formated device: %q with fstype %q; output:\n %q\n,", devicePath, fstype, string(dataOut))
+	return true, err
+}
+
+func probeAttachedVolume() error {
+	executor := exec.New()
+	args := []string{"trigger"}
+	cmd := executor.Command("/usr/bin/udevadm", args...)
+	_, err := cmd.CombinedOutput()
+	if err != nil {
+		glog.Errorf("error running udevadm trigger %v\n", err)
+		return err
+	}
+	glog.V(4).Infof("Successfully probed all attachments")
+	return nil
+}