Add common functionality required for all in-tree to CSI Migration shim code pieces

pkg/controller/volume/attachdetach/testing/testvolumespec.go

@@ -253,6 +253,10 @@ func (plugin *TestPlugin) CanSupport(spec *volume.Spec) bool {
 	return true
 }
 
+func (plugin *TestPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *TestPlugin) RequiresRemount() bool {
 	return false
 }

pkg/controller/volume/persistentvolume/framework_test.go

@@ -1258,6 +1258,10 @@ func (plugin *mockVolumePlugin) CanSupport(spec *vol.Spec) bool {
 	return true
 }
 
+func (plugin *mockVolumePlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *mockVolumePlugin) RequiresRemount() bool {
 	return false
 }

pkg/features/kube_features.go

@@ -390,6 +390,24 @@ const (
 	//
 	// Enables the kubelet's pod resources grpc endpoint
 	KubeletPodResources utilfeature.Feature = "KubeletPodResources"
+
+	// owner: @davidz627
+	// alpha: v1.14
+	//
+	// Enables the in-tree storage to CSI Plugin migration feature.
+	CSIMigration utilfeature.Feature = "CSIMigration"
+
+	// owner: @davidz627
+	// alpha: v1.14
+	//
+	// Enables the GCE PD in-tree driver to GCE CSI Driver migration feature.
+	CSIMigrationGCE utilfeature.Feature = "CSIMigrationGCE"
+
+	// owner: @leakingtapan
+	// alpha: v1.14
+	//
+	// Enables the AWS EBS in-tree driver to AWS EBS CSI Driver migration feature.
+	CSIMigrationAWS utilfeature.Feature = "CSIMigrationAWS"
 )
 
 func init() {
@@ -442,6 +460,9 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	BoundServiceAccountTokenVolume:              {Default: false, PreRelease: utilfeature.Alpha},
 	CRIContainerLogRotation:                     {Default: true, PreRelease: utilfeature.Beta},
 	GCERegionalPersistentDisk:                   {Default: true, PreRelease: utilfeature.GA},
+	CSIMigration:                                {Default: false, PreRelease: utilfeature.Alpha},
+	CSIMigrationGCE:                             {Default: false, PreRelease: utilfeature.Alpha},
+	CSIMigrationAWS:                             {Default: false, PreRelease: utilfeature.Alpha},
 	RunAsGroup:                                  {Default: false, PreRelease: utilfeature.Alpha},
 	VolumeSubpath:                               {Default: true, PreRelease: utilfeature.GA},
 	BalanceAttachedNodeVolumes:                  {Default: false, PreRelease: utilfeature.Alpha},

pkg/volume/awsebs/aws_ebs.go

@@ -86,6 +86,11 @@ func (plugin *awsElasticBlockStorePlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.AWSElasticBlockStore != nil)
 }
 
+func (plugin *awsElasticBlockStorePlugin) IsMigratedToCSI() bool {
+	return utilfeature.DefaultFeatureGate.Enabled(features.CSIMigration) &&
+		utilfeature.DefaultFeatureGate.Enabled(features.CSIMigrationAWS)
+}
+
 func (plugin *awsElasticBlockStorePlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/azure_dd/azure_dd.go

@@ -121,6 +121,10 @@ func (plugin *azureDataDiskPlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.AzureDisk != nil)
 }
 
+func (plugin *azureDataDiskPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *azureDataDiskPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/azure_file/azure_file.go

@@ -80,6 +80,10 @@ func (plugin *azureFilePlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.AzureFile != nil)
 }
 
+func (plugin *azureFilePlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *azureFilePlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/cephfs/cephfs.go

@@ -71,6 +71,10 @@ func (plugin *cephfsPlugin) CanSupport(spec *volume.Spec) bool {
 	return (spec.Volume != nil && spec.Volume.CephFS != nil) || (spec.PersistentVolume != nil && spec.PersistentVolume.Spec.CephFS != nil)
 }
 
+func (plugin *cephfsPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *cephfsPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/cinder/cinder.go

@@ -108,6 +108,10 @@ func (plugin *cinderPlugin) CanSupport(spec *volume.Spec) bool {
 	return (spec.Volume != nil && spec.Volume.Cinder != nil) || (spec.PersistentVolume != nil && spec.PersistentVolume.Spec.Cinder != nil)
 }
 
+func (plugin *cinderPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *cinderPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/configmap/configmap.go

@@ -77,6 +77,10 @@ func (plugin *configMapPlugin) CanSupport(spec *volume.Spec) bool {
 	return spec.Volume != nil && spec.Volume.ConfigMap != nil
 }
 
+func (plugin *configMapPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *configMapPlugin) RequiresRemount() bool {
 	return true
 }

pkg/volume/csi/csi_plugin.go

@@ -279,6 +279,10 @@ func (p *csiPlugin) CanSupport(spec *volume.Spec) bool {
 	return spec.PersistentVolume != nil && spec.PersistentVolume.Spec.CSI != nil
 }
 
+func (p *csiPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (p *csiPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/downwardapi/downwardapi.go

@@ -81,6 +81,10 @@ func (plugin *downwardAPIPlugin) CanSupport(spec *volume.Spec) bool {
 	return spec.Volume != nil && spec.Volume.DownwardAPI != nil
 }
 
+func (plugin *downwardAPIPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *downwardAPIPlugin) RequiresRemount() bool {
 	return true
 }

pkg/volume/emptydir/empty_dir.go

@@ -89,6 +89,10 @@ func (plugin *emptyDirPlugin) CanSupport(spec *volume.Spec) bool {
 	return false
 }
 
+func (plugin *emptyDirPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *emptyDirPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/fc/fc.go

@@ -85,6 +85,10 @@ func (plugin *fcPlugin) CanSupport(spec *volume.Spec) bool {
 	return (spec.Volume != nil && spec.Volume.FC != nil) || (spec.PersistentVolume != nil && spec.PersistentVolume.Spec.FC != nil)
 }
 
+func (plugin *fcPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *fcPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/flexvolume/plugin.go

@@ -149,6 +149,10 @@ func (plugin *flexVolumePlugin) CanSupport(spec *volume.Spec) bool {
 	return sourceDriver == plugin.driverName
 }
 
+func (plugin *flexVolumePlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 // RequiresRemount is part of the volume.VolumePlugin interface.
 func (plugin *flexVolumePlugin) RequiresRemount() bool {
 	return false

pkg/volume/flocker/flocker.go

@@ -108,6 +108,10 @@ func (p *flockerPlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.Flocker != nil)
 }
 
+func (p *flockerPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (p *flockerPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/gcepd/gce_pd.go

@@ -98,6 +98,11 @@ func (plugin *gcePersistentDiskPlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.GCEPersistentDisk != nil)
 }
 
+func (plugin *gcePersistentDiskPlugin) IsMigratedToCSI() bool {
+	return utilfeature.DefaultFeatureGate.Enabled(features.CSIMigration) &&
+		utilfeature.DefaultFeatureGate.Enabled(features.CSIMigrationGCE)
+}
+
 func (plugin *gcePersistentDiskPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/git_repo/git_repo.go

@@ -78,6 +78,10 @@ func (plugin *gitRepoPlugin) CanSupport(spec *volume.Spec) bool {
 	return spec.Volume != nil && spec.Volume.GitRepo != nil
 }
 
+func (plugin *gitRepoPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *gitRepoPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/glusterfs/glusterfs.go

@@ -114,6 +114,10 @@ func (plugin *glusterfsPlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.Glusterfs != nil)
 }
 
+func (plugin *glusterfsPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *glusterfsPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/host_path/host_path.go

@@ -83,6 +83,10 @@ func (plugin *hostPathPlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.HostPath != nil)
 }
 
+func (plugin *hostPathPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *hostPathPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/iscsi/iscsi.go

@@ -76,6 +76,10 @@ func (plugin *iscsiPlugin) CanSupport(spec *volume.Spec) bool {
 	return (spec.Volume != nil && spec.Volume.ISCSI != nil) || (spec.PersistentVolume != nil && spec.PersistentVolume.Spec.ISCSI != nil)
 }
 
+func (plugin *iscsiPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *iscsiPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/local/local.go

@@ -82,6 +82,10 @@ func (plugin *localVolumePlugin) CanSupport(spec *volume.Spec) bool {
 	return (spec.PersistentVolume != nil && spec.PersistentVolume.Spec.Local != nil)
 }
 
+func (plugin *localVolumePlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *localVolumePlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/nfs/nfs.go

@@ -84,6 +84,10 @@ func (plugin *nfsPlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.NFS != nil)
 }
 
+func (plugin *nfsPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *nfsPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/noop_expandable_plugin.go

@@ -48,6 +48,10 @@ func (n *noopExpandableVolumePluginInstance) CanSupport(spec *Spec) bool {
 	return true
 }
 
+func (n *noopExpandableVolumePluginInstance) IsMigratedToCSI() bool {
+	return false
+}
+
 func (n *noopExpandableVolumePluginInstance) RequiresRemount() bool {
 	return false
 }

pkg/volume/photon_pd/photon_pd.go

@@ -74,6 +74,10 @@ func (plugin *photonPersistentDiskPlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.PhotonPersistentDisk != nil)
 }
 
+func (plugin *photonPersistentDiskPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *photonPersistentDiskPlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/plugins.go

@@ -118,6 +118,10 @@ type VolumePlugin interface {
 	// const.
 	CanSupport(spec *Spec) bool
 
+	// IsMigratedToCSI tests whether a CSIDriver implements this plugin's
+	// functionality
+	IsMigratedToCSI() bool
+
 	// RequiresRemount returns true if this plugin requires mount calls to be
 	// reexecuted. Atomically updating volumes, like Downward API, depend on
 	// this to update the contents of the volume.
@@ -601,6 +605,37 @@ func (pm *VolumePluginMgr) FindPluginBySpec(spec *Spec) (VolumePlugin, error) {
 	return matches[0], nil
 }
 
+// IsPluginMigratableBySpec looks for a plugin that can support a given volume
+// specification and whether that plugin is Migratable. If no plugins can
+// support or more than one plugin can support it, return error.
+func (pm *VolumePluginMgr) IsPluginMigratableBySpec(spec *Spec) (bool, error) {
+	pm.mutex.Lock()
+	defer pm.mutex.Unlock()
+
+	if spec == nil {
+		return false, fmt.Errorf("could not find if plugin is migratable because volume spec is nil")
+	}
+
+	matchedPluginNames := []string{}
+	matches := []VolumePlugin{}
+	for k, v := range pm.plugins {
+		if v.CanSupport(spec) {
+			matchedPluginNames = append(matchedPluginNames, k)
+			matches = append(matches, v)
+		}
+	}
+
+	if len(matches) == 0 {
+		// Not a known plugin (flex) in which case it is not migratable
+		return false, nil
+	}
+	if len(matches) > 1 {
+		return false, fmt.Errorf("multiple volume plugins matched: %s", strings.Join(matchedPluginNames, ","))
+	}
+
+	return matches[0].IsMigratedToCSI(), nil
+}
+
 // FindPluginByName fetches a plugin by name or by legacy name.  If no plugin
 // is found, returns error.
 func (pm *VolumePluginMgr) FindPluginByName(name string) (VolumePlugin, error) {

pkg/volume/plugins_test.go

@@ -75,6 +75,10 @@ func (plugin *testPlugins) CanSupport(spec *Spec) bool {
 	return true
 }
 
+func (plugin *testPlugins) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *testPlugins) RequiresRemount() bool {
 	return false
 }

pkg/volume/portworx/portworx.go

@@ -95,6 +95,10 @@ func (plugin *portworxVolumePlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.PortworxVolume != nil)
 }
 
+func (plugin *portworxVolumePlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *portworxVolumePlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/projected/projected.go

@@ -96,6 +96,10 @@ func (plugin *projectedPlugin) CanSupport(spec *volume.Spec) bool {
 	return spec.Volume != nil && spec.Volume.Projected != nil
 }
 
+func (plugin *projectedPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *projectedPlugin) RequiresRemount() bool {
 	return true
 }

pkg/volume/quobyte/quobyte.go

@@ -110,6 +110,10 @@ func (plugin *quobytePlugin) CanSupport(spec *volume.Spec) bool {
 	return false
 }
 
+func (plugin *quobytePlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *quobytePlugin) RequiresRemount() bool {
 	return false
 }

pkg/volume/rbd/rbd.go

@@ -107,6 +107,10 @@ func (plugin *rbdPlugin) CanSupport(spec *volume.Spec) bool {
 	return (spec.Volume != nil && spec.Volume.RBD != nil) || (spec.PersistentVolume != nil && spec.PersistentVolume.Spec.RBD != nil)
 }
 
+func (plugin *rbdPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (plugin *rbdPlugin) RequiresRemount() bool {
 	return false
 }