rbd: Add support for rbd ROX PVC mounting

if the PVC access mode is ReadOnlyMany
or single node readonly, mounting the rbd
device path to the staging path as readonly
to avoid the write operation.

If the PVC acccess mode is readonly, mapping
rbd images as readonly.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

e2e/rbd.go

@@ -5,6 +5,8 @@ import (
 	"strings"
 
 	. "github.com/onsi/ginkgo" // nolint
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/kubernetes/test/e2e/framework"
 	e2elog "k8s.io/kubernetes/test/e2e/framework/log"
@@ -602,6 +604,122 @@ var _ = Describe("RBD", func() {
 				createRBDStorageClass(f.ClientSet, f, nil, nil)
 			})
 
+			By("create ROX PVC clone and mount it to multiple pods", func() {
+				v, err := f.ClientSet.Discovery().ServerVersion()
+				if err != nil {
+					e2elog.Logf("failed to get server version with error %v", err)
+					Fail(err.Error())
+				}
+				// snapshot beta is only supported from v1.17+
+				if v.Major > "1" || (v.Major == "1" && v.Minor >= "17") {
+					// create pvc and bind it to an app
+					pvc, err := loadPVC(pvcPath)
+					if err != nil {
+						Fail(err.Error())
+					}
+
+					pvc.Namespace = f.UniqueName
+					app, err := loadApp(appPath)
+					if err != nil {
+						Fail(err.Error())
+					}
+					app.Namespace = f.UniqueName
+					err = createPVCAndApp("", f, pvc, app, deployTimeout)
+					if err != nil {
+						Fail(err.Error())
+					}
+
+					// delete pod as we should not create snapshot for in-use pvc
+					err = deletePod(app.Name, app.Namespace, f.ClientSet, deployTimeout)
+					if err != nil {
+						Fail(err.Error())
+					}
+
+					snap := getSnapshot(snapshotPath)
+					snap.Namespace = f.UniqueName
+					snap.Spec.Source.PersistentVolumeClaimName = &pvc.Name
+
+					err = createSnapshot(&snap, deployTimeout)
+					if err != nil {
+						Fail(err.Error())
+					}
+
+					pvcClone, err := loadPVC(pvcClonePath)
+					if err != nil {
+						Fail(err.Error())
+					}
+
+					// create clone PVC as ROX
+					pvcClone.Namespace = f.UniqueName
+					pvcClone.Spec.AccessModes = []v1.PersistentVolumeAccessMode{v1.ReadOnlyMany}
+					err = createPVCAndvalidatePV(f.ClientSet, pvcClone, deployTimeout)
+					if err != nil {
+						Fail(err.Error())
+					}
+					appClone, err := loadApp(appClonePath)
+					if err != nil {
+						Fail(err.Error())
+					}
+
+					totalCount := 4
+					appClone.Namespace = f.UniqueName
+					appClone.Spec.Volumes[0].PersistentVolumeClaim.ClaimName = pvcClone.Name
+
+					// create pvc and app
+					for i := 0; i < totalCount; i++ {
+						name := fmt.Sprintf("%s%d", f.UniqueName, i)
+						label := map[string]string{
+							"app": name,
+						}
+						appClone.Labels = label
+						appClone.Name = name
+						err = createApp(f.ClientSet, appClone, deployTimeout)
+						if err != nil {
+							Fail(err.Error())
+						}
+					}
+
+					for i := 0; i < totalCount; i++ {
+						name := fmt.Sprintf("%s%d", f.UniqueName, i)
+						opt := metav1.ListOptions{
+							LabelSelector: fmt.Sprintf("app=%s", name),
+						}
+
+						filePath := appClone.Spec.Containers[0].VolumeMounts[0].MountPath + "/test"
+						_, stdErr := execCommandInPodAndAllowFail(f, fmt.Sprintf("echo 'Hello World' > %s", filePath), appClone.Namespace, &opt)
+						readOnlyErr := fmt.Sprintf("cannot create %s: Read-only file system", filePath)
+						if !strings.Contains(stdErr, readOnlyErr) {
+							Fail(stdErr)
+						}
+					}
+
+					// delete app
+					for i := 0; i < totalCount; i++ {
+						name := fmt.Sprintf("%s%d", f.UniqueName, i)
+						appClone.Name = name
+						err = deletePod(appClone.Name, appClone.Namespace, f.ClientSet, deployTimeout)
+						if err != nil {
+							Fail(err.Error())
+						}
+					}
+					// delete pvc clone
+					err = deletePVCAndValidatePV(f.ClientSet, pvcClone, deployTimeout)
+					if err != nil {
+						Fail(err.Error())
+					}
+					// delete snapshot
+					err = deleteSnapshot(&snap, deployTimeout)
+					if err != nil {
+						Fail(err.Error())
+					}
+					// delete parent pvc
+					err = deletePVCAndValidatePV(f.ClientSet, pvc, deployTimeout)
+					if err != nil {
+						Fail(err.Error())
+					}
+				}
+			})
+
 			// Make sure this should be last testcase in this file, because
 			// it deletes pool
 			By("Create a PVC and Delete PVC when backend pool deleted", func() {