Add Delete Volume Finalizer

This PR adds Finalizer on the snapshot source PVC to prevent it
from being deleted when a snapshot is being created from it.

pkg/controller/snapshot_finalizer_test.go

@@ -0,0 +1,67 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package controller
+
+import (
+	"testing"
+
+	"k8s.io/api/core/v1"
+)
+
+// Test single call to ensureSnapshotSourceFinalizer and checkandRemoveSnapshotSourceFinalizer,
+// expecting PVCFinalizer to be added or removed
+func TestPVCFinalizer(t *testing.T) {
+
+	tests := []controllerTest{
+		{
+			name:             "1-1 - successful add PVC finalizer",
+			initialSnapshots: newSnapshotArray("snap6-2", classSilver, "", "snapuid6-2", "claim6-2", false, nil, nil, nil),
+			initialClaims:    newClaimArray("claim6-2", "pvc-uid6-2", "1Gi", "volume6-2", v1.ClaimBound, &classEmpty),
+			test:             testAddPVCFinalizer,
+			expectSuccess:    true,
+		},
+		{
+			name:             "1-2 - won't add PVC finalizer; already added",
+			initialSnapshots: newSnapshotArray("snap6-2", classSilver, "", "snapuid6-2", "claim6-2", false, nil, nil, nil),
+			initialClaims:    newClaimArrayFinalizer("claim6-2", "pvc-uid6-2", "1Gi", "volume6-2", v1.ClaimBound, &classEmpty),
+			test:             testAddPVCFinalizer,
+			expectSuccess:    false,
+		},
+		{
+			name:             "1-3 - successful remove PVC finalizer",
+			initialSnapshots: newSnapshotArray("snap6-2", classSilver, "", "snapuid6-2", "claim6-2", false, nil, nil, nil),
+			initialClaims:    newClaimArrayFinalizer("claim6-2", "pvc-uid6-2", "1Gi", "volume6-2", v1.ClaimBound, &classEmpty),
+			test:             testRemovePVCFinalizer,
+			expectSuccess:    true,
+		},
+		{
+			name:             "1-4 - won't remove PVC finalizer; already removed",
+			initialSnapshots: newSnapshotArray("snap6-2", classSilver, "", "snapuid6-2", "claim6-2", false, nil, nil, nil),
+			initialClaims:    newClaimArray("claim6-2", "pvc-uid6-2", "1Gi", "volume6-2", v1.ClaimBound, &classEmpty),
+			test:             testRemovePVCFinalizer,
+			expectSuccess:    false,
+		},
+		{
+			name:             "1-5 - won't remove PVC finalizer; PVC in-use",
+			initialSnapshots: newSnapshotArray("snap6-2", classSilver, "", "snapuid6-2", "claim6-2", false, nil, nil, nil),
+			initialClaims:    newClaimArray("claim6-2", "pvc-uid6-2", "1Gi", "volume6-2", v1.ClaimBound, &classEmpty),
+			test:             testRemovePVCFinalizer,
+			expectSuccess:    false,
+		},
+	}
+	runPVCFinalizerTests(t, tests, snapshotClasses)
+}