storage: Handle RBD snapshot deletion (#3615)

When deleting volume snapshots, only records in the database are deleted, and snapshots are not deleted on the main storage.

Fixes: #3586

Author: Gabriel Beims Bräscher

engine/storage/snapshot/src/main/java/org/apache/cloudstack/storage/snapshot/CephSnapshotStrategy.java

@@ -56,9 +56,18 @@ public StrategyPriority canHandle(Snapshot snapshot, SnapshotOperation op) {
             return StrategyPriority.CANT_HANDLE;
         }
 
-        if (SnapshotOperation.REVERT.equals(op) && isSnapshotStoredOnRbdStoragePool(snapshot)) {
+        if (!isSnapshotStoredOnRbdStoragePool(snapshot)) {
+            return StrategyPriority.CANT_HANDLE;
+        }
+
+        if (SnapshotOperation.REVERT.equals(op)) {
             return StrategyPriority.HIGHEST;
         }
+
+        if (SnapshotOperation.DELETE.equals(op)) {
+            return StrategyPriority.HIGHEST;
+        }
+
         return StrategyPriority.CANT_HANDLE;
     }
 

engine/storage/snapshot/src/test/java/org/apache/cloudstack/storage/snapshot/CephSnapshotStrategyTest.java

@@ -87,6 +87,8 @@ private void configureAndVerifyCanHandle(Date removed, boolean isSnapshotStoredO
             StrategyPriority strategyPriority = cephSnapshotStrategy.canHandle(snapshot, snapshotOps[i]);
             if (snapshotOps[i] == SnapshotOperation.REVERT && isSnapshotStoredOnRbdStoragePool) {
                 Assert.assertEquals(StrategyPriority.HIGHEST, strategyPriority);
+            } else if (snapshotOps[i] == SnapshotOperation.DELETE && isSnapshotStoredOnRbdStoragePool) {
+                Assert.assertEquals(StrategyPriority.HIGHEST, strategyPriority);
             } else {
                 Assert.assertEquals(StrategyPriority.CANT_HANDLE, strategyPriority);
             }

plugins/storage/volume/default/src/main/java/org/apache/cloudstack/storage/datastore/driver/CloudStackPrimaryDataStoreDriverImpl.java

@@ -82,7 +82,7 @@ public class CloudStackPrimaryDataStoreDriverImpl implements PrimaryDataStoreDri
     @Override
     public Map<String, String> getCapabilities() {
         Map<String, String> caps = new HashMap<String, String>();
-        caps.put(DataStoreCapabilities.VOLUME_SNAPSHOT_QUIESCEVM.toString(), "false");
+        caps.put(DataStoreCapabilities.VOLUME_SNAPSHOT_QUIESCEVM.toString(), Boolean.FALSE.toString());
         return caps;
     }