Support mounting and deleting version 1.0.0 RBD volumes

This commit adds support to mount and delete volumes provisioned by older
plugin versions (1.0.0) in order to support backward compatibility to 1.0.0
created volumes.

It adds back the ability to specify where older meta data was specified, using
the metadatastorage option to the plugin. Further, using the provided meta data
to mount and delete the older volumes.

It also supports a variety of ways in which monitor information may have been
specified (in the storage class, or in the secret), to keep the monitor
information current.

Testing done:
- Mount/Delete 1.0.0 plugin created volume with monitors in the StorageClass
- Mount/Delete 1.0.0 plugin created volume with monitors in the secret with
  a key "monitors"
- Mount/Delete 1.0.0 plugin created volume with monitors in the secret with
  a user specified key
- PVC creation and deletion with the current version (to ensure at the minimum
  no broken functionality)
- Tested some negative cases, where monitor information is missing in secrets
  or present with a different key name, to understand if failure scenarios work
  as expected

Updates #378

Follow-up work:
- Documentation on how to upgrade to 1.1 plugin and retain above functionality
  for older volumes

Signed-off-by: ShyamsundarR <srangana@redhat.com>

pkg/rbd/rbd_util.go

@@ -27,6 +27,7 @@ import (
 
 	"github.com/golang/protobuf/ptypes"
 	"github.com/golang/protobuf/ptypes/timestamp"
+	"github.com/pborman/uuid"
 	"github.com/pkg/errors"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/klog"
@@ -45,20 +46,28 @@ const (
 
 // rbdVolume represents a CSI volume and its RBD image specifics
 type rbdVolume struct {
-	// RbdImageName is the name of the RBD image backing this rbdVolume
+	// RbdImageName is the name of the RBD image backing this rbdVolume. This does not have a
+	//   JSON tag as it is not stashed in JSON encoded config maps in v1.0.0
 	// VolID is the volume ID that is exchanged with CSI drivers, identifying this rbdVol
-	// RequestName is the CSI generated volume name for the rbdVolume
+	// RequestName is the CSI generated volume name for the rbdVolume.  This does not have a
+	//   JSON tag as it is not stashed in JSON encoded config maps in v1.0.0
+	// VolName and MonValueFromSecret are retained from older plugin versions (<= 1.0.0)
+	//   for backward compatibility reasons
 	RbdImageName       string
-	VolID              string
-	Monitors           string
-	Pool               string
-	ImageFormat        string
-	ImageFeatures      string
-	VolSize            int64
-	Mounter            string
-	DisableInUseChecks bool
-	ClusterID          string
+	VolID              string `json:"volID"`
+	Monitors           string `json:"monitors"`
+	Pool               string `json:"pool"`
+	ImageFormat        string `json:"imageFormat"`
+	ImageFeatures      string `json:"imageFeatures"`
+	VolSize            int64  `json:"volSize"`
+	AdminID            string `json:"adminId"`
+	UserID             string `json:"userId"`
+	Mounter            string `json:"mounter"`
+	DisableInUseChecks bool   `json:"disableInUseChecks"`
+	ClusterID          string `json:"clusterId"`
 	RequestName        string
+	VolName            string `json:"volName"`
+	MonValueFromSecret string `json:"monValueFromSecret"`
 }
 
 // rbdSnapshot represents a CSI snapshot and its RBD snapshot specifics
@@ -89,6 +98,8 @@ var (
 	snapshotNameLocker = util.NewIDLocker()
 	// serializes operations based on "mount target path" as key
 	targetPathLocker = util.NewIDLocker()
+	// serializes delete operations on legacy volumes
+	legacyVolumeIDLocker = util.NewIDLocker()
 
 	supportedFeatures = sets.NewString("layering")
 )
@@ -172,14 +183,6 @@ func deleteImage(pOpts *rbdVolume, cr *util.Credentials) error {
 	output, err = execCommand("rbd", args)
 	if err != nil {
 		klog.Errorf("failed to delete rbd image: %v, command output: %s", err, string(output))
-		return err
-	}
-
-	err = undoVolReservation(pOpts, cr)
-	if err != nil {
-		klog.Errorf("failed to remove reservation for volume (%s) with backing image (%s) (%s)",
-			pOpts.RequestName, pOpts.RbdImageName, err)
-		err = nil
 	}
 
 	return err
@@ -283,9 +286,8 @@ func genVolFromVolID(rbdVol *rbdVolume, volumeID string, cr *util.Credentials) e
 
 	err := vi.DecomposeCSIID(rbdVol.VolID)
 	if err != nil {
-		klog.V(4).Infof("error decoding volume ID (%s) (%s)", err, rbdVol.VolID)
-		return err
-
+		err = fmt.Errorf("error decoding volume ID (%s) (%s)", err, rbdVol.VolID)
+		return ErrInvalidVolID{err}
 	}
 
 	rbdVol.ClusterID = vi.ClusterID
@@ -336,7 +338,66 @@ func getMonsAndClusterID(options map[string]string) (monitors, clusterID string,
 	return
 }
 
-func genVolFromVolumeOptions(volOptions map[string]string, disableInUseChecks bool) (*rbdVolume, error) {
+// isLegacyVolumeID checks if passed in volume ID string conforms to volume ID naming scheme used
+// by the version 1.0.0 (legacy) of the plugin, and returns true if found to be conforming
+func isLegacyVolumeID(volumeID string) bool {
+	// Version 1.0.0 volumeID format: "csi-rbd-vol-" + UUID string
+	//    length: 12 ("csi-rbd-vol-") + 36 (UUID string)
+
+	// length check
+	if len(volumeID) != 48 {
+		return false
+	}
+
+	// Header check
+	if !strings.HasPrefix(volumeID, "csi-rbd-vol-") {
+		return false
+	}
+
+	// Trailer UUID format check
+	if uuid.Parse(volumeID[12:]) == nil {
+		return false
+	}
+
+	return true
+}
+
+// upadateMons function is used to update the rbdVolume.Monitors for volumes that were provisioned
+// using the 1.0.0 version (legacy) of the plugin.
+func updateMons(rbdVol *rbdVolume, options, credentials map[string]string) error {
+	var ok bool
+
+	// read monitors and MonValueFromSecret from options, else check passed in rbdVolume for
+	// MonValueFromSecret key in credentials
+	monInSecret := ""
+	if options != nil {
+		if rbdVol.Monitors, ok = options["monitors"]; !ok {
+			rbdVol.Monitors = ""
+		}
+		if monInSecret, ok = options["monValueFromSecret"]; !ok {
+			monInSecret = ""
+		}
+	} else {
+		monInSecret = rbdVol.MonValueFromSecret
+	}
+
+	// if monitors are present in secrets and we have the credentials, use monitors from the
+	// credentials overriding monitors from other sources
+	if monInSecret != "" && credentials != nil {
+		monsFromSecret, ok := credentials[monInSecret]
+		if ok {
+			rbdVol.Monitors = monsFromSecret
+		}
+	}
+
+	if rbdVol.Monitors == "" {
+		return errors.New("either monitors or monValueFromSecret must be set")
+	}
+
+	return nil
+}
+
+func genVolFromVolumeOptions(volOptions, credentials map[string]string, disableInUseChecks, isLegacyVolume bool) (*rbdVolume, error) {
 	var (
 		ok  bool
 		err error
@@ -348,9 +409,16 @@ func genVolFromVolumeOptions(volOptions map[string]string, disableInUseChecks bo
 		return nil, errors.New("missing required parameter pool")
 	}
 
-	rbdVol.Monitors, rbdVol.ClusterID, err = getMonsAndClusterID(volOptions)
-	if err != nil {
-		return nil, err
+	if isLegacyVolume {
+		err = updateMons(rbdVol, volOptions, credentials)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		rbdVol.Monitors, rbdVol.ClusterID, err = getMonsAndClusterID(volOptions)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	rbdVol.ImageFormat, ok = volOptions["imageFormat"]
@@ -372,7 +440,6 @@ func genVolFromVolumeOptions(volOptions map[string]string, disableInUseChecks bo
 			}
 			rbdVol.ImageFeatures = imageFeatures
 		}
-
 	}
 
 	klog.V(3).Infof("setting disableInUseChecks on rbd volume to: %v", disableInUseChecks)