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Merge pull request #41196 from bigstepinc/master

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Automatic merge from submit-queue

Fix for Premature iSCSI logout #39202.

**What this PR does / why we need it**:

Modifies the iSCSI volume plugin code to prevent premature iSCSI logouts and the establishment of multiple iSCSI connections to the same target in certain cases.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #39202, fixes #41041, fixes #40941

**Special notes for your reviewer**:

The existing iSCSI connections are now rescanned on every AttachDisk call to discover newly created LUNs.

The disk mount points now contain an additional directory in the path corresponding to the disk iface that is later used for iSCSI logout.

The device prefixes that are used to count the existing references to the portal-target pair now contain the whole path including the mount point until the lun index.

**Release note**:
```release-note
Fixed issues #39202, #41041 and #40941 that caused the iSCSI connections to be prematurely closed when deleting a pod with an iSCSI persistent volume attached and that prevented the use of newly created LUNs on targets with preestablished connections.
```
This commit is contained in:
Kubernetes Submit Queue 2017-02-15 04:11:55 -08:00 committed by GitHub
commit a50ea2fc37
2 changed files with 62 additions and 17 deletions
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59
pkg/volume/iscsi/iscsi_util.go Normal file → Executable file
View File

@ -90,21 +90,22 @@ func getDevicePrefixRefCount(mounter mount.Interface, deviceNamePrefix string) (
return refCount, nil
}
// make a directory like /var/lib/kubelet/plugins/kubernetes.io/iscsi/portal-some_iqn-lun-lun_id
func makePDNameInternal(host volume.VolumeHost, portal string, iqn string, lun string) string {
return path.Join(host.GetPluginDir(iscsiPluginName), portal+"-"+iqn+"-lun-"+lun)
// make a directory like /var/lib/kubelet/plugins/kubernetes.io/iscsi/iface_name/portal-some_iqn-lun-lun_id
func makePDNameInternal(host volume.VolumeHost, portal string, iqn string, lun string, iface string) string {
return path.Join(host.GetPluginDir(iscsiPluginName), "iface-"+iface, portal+"-"+iqn+"-lun-"+lun)
}
type ISCSIUtil struct{}
func (util *ISCSIUtil) MakeGlobalPDName(iscsi iscsiDisk) string {
return makePDNameInternal(iscsi.plugin.host, iscsi.portals[0], iscsi.iqn, iscsi.lun)
return makePDNameInternal(iscsi.plugin.host, iscsi.portals[0], iscsi.iqn, iscsi.lun, iscsi.iface)
}
func (util *ISCSIUtil) AttachDisk(b iscsiDiskMounter) error {
var devicePath string
var devicePaths []string
var iscsiTransport string
out, err := b.plugin.execCommand("iscsiadm", []string{"-m", "iface", "-I", b.iface, "-o", "show"})
if err != nil {
glog.Errorf("iscsi: could not read iface %s error: %s", b.iface, string(out))
@ -112,8 +113,16 @@ func (util *ISCSIUtil) AttachDisk(b iscsiDiskMounter) error {
}
iscsiTransport = extractTransportname(string(out))
bkpPortal := b.portals
for _, tp := range bkpPortal {
// Rescan sessions to discover newly mapped LUNs. Do not specify the interface when rescanning
// to avoid establishing additional sessions to the same target.
out, err := b.plugin.execCommand("iscsiadm", []string{"-m", "node", "-p", tp, "-T", b.iqn, "-R"})
if err != nil {
glog.Errorf("iscsi: failed to rescan session with error: %s (%v)", string(out), err)
}
if iscsiTransport == "" {
glog.Errorf("iscsi: could not find transport name in iface %s", b.iface)
return errors.New(fmt.Sprintf("Could not parse iface file for %s", b.iface))
@ -207,18 +216,29 @@ func (util *ISCSIUtil) DetachDisk(c iscsiDiskUnmounter, mntPath string) error {
return err
}
refCount, err := getDevicePrefixRefCount(c.mounter, prefix)
if err == nil && refCount == 0 {
// this portal/iqn are no longer referenced, log out
// extract portal and iqn from device path
// This portal/iqn/iface is no longer referenced, log out.
// Extract the portal and iqn from device path.
portal, iqn, err := extractPortalAndIqn(device)
if err != nil {
return err
}
glog.Infof("iscsi: log out target %s iqn %s", portal, iqn)
out, err := c.plugin.execCommand("iscsiadm", []string{"-m", "node", "-p", portal, "-T", iqn, "--logout"})
if err != nil {
glog.Errorf("iscsi: failed to detach disk Error: %s", string(out))
// Extract the iface from the mountPath and use it to log out. If the iface
// is not found, maintain the previous behavior to facilitate kubelet upgrade.
// Logout may fail as no session may exist for the portal/IQN on the specified interface.
iface, found := extractIface(mntPath)
if found {
glog.Infof("iscsi: log out target %s iqn %s iface %s", portal, iqn, iface)
out, err := c.plugin.execCommand("iscsiadm", []string{"-m", "node", "-p", portal, "-T", iqn, "-I", iface, "--logout"})
if err != nil {
glog.Errorf("iscsi: failed to detach disk Error: %s", string(out))
}
} else {
glog.Infof("iscsi: log out target %s iqn %s", portal, iqn)
out, err := c.plugin.execCommand("iscsiadm", []string{"-m", "node", "-p", portal, "-T", iqn, "--logout"})
if err != nil {
glog.Errorf("iscsi: failed to detach disk Error: %s", string(out))
}
}
}
}
@ -248,15 +268,26 @@ func extractDeviceAndPrefix(mntPath string) (string, string, error) {
return "", "", fmt.Errorf("iscsi detach disk: malformatted mnt path: %s", mntPath)
}
device := mntPath[(ind + 1):]
// strip -lun- from device path
ind = strings.LastIndex(device, "-lun-")
// strip -lun- from mount path
ind = strings.LastIndex(mntPath, "-lun-")
if ind < 0 {
return "", "", fmt.Errorf("iscsi detach disk: malformatted mnt path: %s", mntPath)
}
prefix := device[:ind]
prefix := mntPath[:ind]
return device, prefix, nil
}
func extractIface(mntPath string) (string, bool) {
re := regexp.MustCompile(`.+/iface-([^/]+)/.+`)
re_output := re.FindStringSubmatch(mntPath)
if re_output != nil {
return re_output[1], true
}
return "", false
}
func extractPortalAndIqn(device string) (string, string, error) {
ind1 := strings.Index(device, "-")
if ind1 < 0 {

20
pkg/volume/iscsi/iscsi_util_test.go Normal file → Executable file
View File

@ -57,10 +57,24 @@ func TestGetDevicePrefixRefCount(t *testing.T) {
func TestExtractDeviceAndPrefix(t *testing.T) {
devicePath := "127.0.0.1:3260-iqn.2014-12.com.example:test.tgt00"
mountPrefix := "/var/lib/kubelet/plugins/kubernetes.io/iscsi/iface-default/" + devicePath
lun := "-lun-0"
device, prefix, err := extractDeviceAndPrefix("/var/lib/kubelet/plugins/kubernetes.io/iscsi/" + devicePath + lun)
if err != nil || device != (devicePath+lun) || prefix != devicePath {
t.Errorf("extractDeviceAndPrefix: expected %s and %s, got %v %s and %s", devicePath+lun, devicePath, err, device, prefix)
device, prefix, err := extractDeviceAndPrefix(mountPrefix + lun)
if err != nil || device != (devicePath+lun) || prefix != mountPrefix {
t.Errorf("extractDeviceAndPrefix: expected %s and %s, got %v %s and %s", devicePath+lun, mountPrefix, err, device, prefix)
}
}
func TestExtractIface(t *testing.T) {
ifaceName := "default"
devicePath := "127.0.0.1:3260-iqn.2014-12.com.example:test.tgt00-lun-0"
iface, found := extractIface("/var/lib/kubelet/plugins/kubernetes.io/iscsi/iface-" + ifaceName + "/" + devicePath)
if !found || iface != ifaceName {
t.Errorf("extractIface: expected %s and %t, got %s and %t", ifaceName, true, iface, found)
}
iface, found = extractIface("/var/lib/kubelet/plugins/kubernetes.io/iscsi/" + devicePath)
if found || iface != "" {
t.Errorf("extractIface: expected %s and %t, got %s and %t", "", false, iface, found)
}
}