rbd: add generic ephemeral volume validation

This commit adds the validation of csi RBD driver to work with
ephemeral volume support. With ephemeral volume support a user can
specify ephemeral volumes in its pod spec and tie the lifecycle
of the PVC with the POD.

An example POD spec looks like this:

kind: Pod
apiVersion: v1
metadata:
  name: my-app
   spec:
  containers:
    - name: csi-rbd-demo-pod
      image: busybox
      volumeMounts:
        - mountPath: "/scratch"
          name: mypvc
      command: [ "sleep", "1000000" ]
  volumes:
    - name: mypvc
      ephemeral:
        volumeClaimTemplate:
          spec:
            accessModes: [ "ReadWriteOnce" ]
            storageClassName: "csi-rbd-sc"
            resources:
              requests:
                storage: 1Gi

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

e2e/rbd.go

@@ -57,6 +57,7 @@ var (
 	appClonePath           = rbdExamplePath + "pod-restore.yaml"
 	appSmartClonePath      = rbdExamplePath + "pod-clone.yaml"
 	appBlockSmartClonePath = rbdExamplePath + "block-pod-clone.yaml"
+	appEphemeralPath       = rbdExamplePath + "pod-ephemeral.yaml"
 	snapshotPath           = rbdExamplePath + "snapshot.yaml"
 	defaultCloneCount      = 10
 
@@ -367,6 +368,28 @@ var _ = Describe("RBD", func() {
 					}
 				})
 			}
+			By("verify ephemeral volume support", func() {
+				// create application
+				app, err := loadApp(appEphemeralPath)
+				if err != nil {
+					e2elog.Failf("failed to load application with error %v", err)
+				}
+				app.Namespace = f.UniqueName
+				err = createApp(f.ClientSet, app, deployTimeout)
+				if err != nil {
+					e2elog.Failf("failed to create application with error %v", err)
+				}
+				// validate created backend rbd images
+				validateRBDImageCount(f, 1, defaultRBDPool)
+
+				err = deletePod(app.Name, app.Namespace, f.ClientSet, deployTimeout)
+				if err != nil {
+					e2elog.Failf("failed to delete application with error %v", err)
+				}
+				// validate created backend rbd images
+				validateRBDImageCount(f, 0, defaultRBDPool)
+			})
+
 			// todo: may be remove the below deletion test later once the migration nodestage tests are adjusted
 			// also to have deletion validation through the same.
 			By("validate RBD migration+static Block PVC Deletion", func() {

examples/rbd/pod-ephemeral.yaml

@@ -0,0 +1,22 @@
+---
+kind: Pod
+apiVersion: v1
+metadata:
+  name: csi-rbd-demo-ephemeral-pod
+spec:
+  containers:
+    - name: web-server
+      image: docker.io/library/nginx:latest
+      volumeMounts:
+        - mountPath: "/myspace"
+          name: mypvc
+  volumes:
+    - name: mypvc
+      ephemeral:
+        volumeClaimTemplate:
+          spec:
+            accessModes: ["ReadWriteOnce"]
+            storageClassName: "csi-rbd-sc"
+            resources:
+              requests:
+                storage: 1Gi