Watcher: Use existing plugin hook to delete all old templates (elastic/x-pack-elasticsearch#1425)

This commit ensures the old 5.x index templates are removed
using the existing plugin hook, instead of the self written part.

Original commit: elastic/x-pack-elasticsearch@6faf08d98d

plugin/src/main/java/org/elasticsearch/xpack/XPackPlugin.java

@@ -14,6 +14,7 @@ import org.elasticsearch.bootstrap.BootstrapCheck;
 import org.elasticsearch.client.Client;
 import org.elasticsearch.client.transport.TransportClient;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
+import org.elasticsearch.cluster.metadata.IndexTemplateMetaData;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.inject.Binder;
@@ -466,7 +467,11 @@ public class XPackPlugin extends Plugin implements ScriptPlugin, ActionPlugin, I
         entries.addAll(machineLearning.getNamedXContent());
         entries.addAll(licensing.getNamedXContent());
         return entries;
+    }
 
+    @Override
+    public UnaryOperator<Map<String, IndexTemplateMetaData>> getIndexTemplateMetaDataUpgrader() {
+        return watcher.getIndexTemplateMetaDataUpgrader();
     }
 
     public void onIndexModule(IndexModule module) {

plugin/src/main/java/org/elasticsearch/xpack/watcher/Watcher.java

@@ -10,6 +10,7 @@ import org.elasticsearch.action.ActionRequest;
 import org.elasticsearch.action.ActionResponse;
 import org.elasticsearch.cluster.NamedDiff;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
+import org.elasticsearch.cluster.metadata.IndexTemplateMetaData;
 import org.elasticsearch.cluster.metadata.MetaData;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
 import org.elasticsearch.cluster.service.ClusterService;
@@ -165,6 +166,7 @@ import java.util.Set;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
+import java.util.function.UnaryOperator;
 import java.util.stream.Collectors;
 
 import static java.util.Collections.emptyList;
@@ -505,4 +507,14 @@ public class Watcher implements ActionPlugin, ScriptPlugin {
                 " that any future history indices after 6 months with the pattern " +
                 "[.watcher-history-YYYY.MM.dd] are allowed to be created", value);
     }
+
+    // These are all old templates from pre 6.0 era, that need to be deleted
+    public UnaryOperator<Map<String, IndexTemplateMetaData>> getIndexTemplateMetaDataUpgrader() {
+        return map -> {
+            map.keySet().removeIf(name -> "watches".equals(name) || "triggered_watches".equals(name)
+                        || name.startsWith("watch_history_"));
+
+            return map;
+        };
+    }
 }

plugin/src/main/java/org/elasticsearch/xpack/watcher/support/WatcherIndexTemplateRegistry.java

@@ -98,22 +98,6 @@ public class WatcherIndexTemplateRegistry extends AbstractComponent implements C
         }
 
         addTemplatesIfMissing(state);
-        deleteDeprecatedTemplates(state);
-    }
-
-    /**
-     * This methods deletes the 5.x watcher index templates
-     * @param state The current cluster state
-     */
-    private void deleteDeprecatedTemplates(ClusterState state) {
-        for (ObjectCursor<String> cursor : state.metaData().getTemplates().keys()) {
-            String name = cursor.value;
-            if ("watches".equals(name) || "triggered_watches".equals(name) || name.startsWith("watcher_history_")) {
-                client.deleteTemplate(new DeleteIndexTemplateRequest(name), ActionListener.wrap(
-                        r -> logger.debug("Deleted old index template [{}]", name),
-                        e -> logger.debug("Could not delete watcher template [{}]: [{}]", name, e.getMessage())));
-            }
-        }
     }
 
     void addTemplatesIfMissing(ClusterState state) {

plugin/src/test/java/org/elasticsearch/xpack/watcher/OldWatcherIndicesBackwardsCompatibilityTests.java

@@ -8,7 +8,9 @@ package org.elasticsearch.xpack.watcher;
 import org.apache.lucene.util.LuceneTestCase.AwaitsFix;
 import org.elasticsearch.AbstractOldXPackIndicesBackwardsCompatibilityTestCase;
 import org.elasticsearch.Version;
+import org.elasticsearch.action.admin.indices.template.get.GetIndexTemplatesResponse;
 import org.elasticsearch.action.search.SearchResponse;
+import org.elasticsearch.cluster.metadata.IndexTemplateMetaData;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.xpack.XPackSettings;
 import org.elasticsearch.xpack.common.text.TextTemplate;
@@ -31,9 +33,11 @@ import static org.elasticsearch.common.unit.TimeValue.timeValueSeconds;
 import static org.hamcrest.Matchers.everyItem;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 import static org.hamcrest.Matchers.hasEntry;
+import static org.hamcrest.Matchers.hasItems;
 import static org.hamcrest.Matchers.hasKey;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.startsWith;
 
 /**
  * Tests for watcher indexes created before 5.0.
@@ -62,6 +66,7 @@ public class OldWatcherIndicesBackwardsCompatibilityTests extends AbstractOldXPa
         });
 
         try {
+            assertOldTemplatesAreDeleted();
             assertWatchIndexContentsWork(version);
             assertBasicWatchInteractions();
         } finally {
@@ -73,6 +78,12 @@ public class OldWatcherIndicesBackwardsCompatibilityTests extends AbstractOldXPa
         }
     }
 
+    private void assertOldTemplatesAreDeleted() {
+        GetIndexTemplatesResponse response = client().admin().indices().prepareGetTemplates().get();
+        List<String> templateNames = response.getIndexTemplates().stream().map(IndexTemplateMetaData::getName).collect(Collectors.toList());
+        assertThat(templateNames, not(hasItems(is("watches"), startsWith("watch-history"), is("triggered_watches"))));
+    }
+
     void assertWatchIndexContentsWork(Version version) throws Exception {
         WatcherClient watcherClient = new WatcherClient(client());
 

plugin/src/test/java/org/elasticsearch/xpack/watcher/support/WatcherIndexTemplateRegistryTests.java

@@ -5,7 +5,6 @@
  */
 package org.elasticsearch.xpack.watcher.support;
 
-import org.elasticsearch.action.admin.indices.template.delete.DeleteIndexTemplateRequest;
 import org.elasticsearch.action.admin.indices.template.put.PutIndexTemplateRequest;
 import org.elasticsearch.client.AdminClient;
 import org.elasticsearch.client.Client;
@@ -29,19 +28,14 @@ import org.elasticsearch.xpack.security.InternalClient;
 import org.junit.Before;
 import org.mockito.ArgumentCaptor;
 
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
-import java.util.stream.Collectors;
 
 import static org.elasticsearch.mock.orig.Mockito.verify;
 import static org.elasticsearch.mock.orig.Mockito.when;
-import static org.hamcrest.Matchers.hasItem;
-import static org.hamcrest.Matchers.hasSize;
-import static org.hamcrest.Matchers.startsWith;
 import static org.mockito.Matchers.anyObject;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.mock;
@@ -96,52 +90,6 @@ public class WatcherIndexTemplateRegistryTests extends ESTestCase {
         return event;
     }
 
-    public void testThatDeprecatedTemplatesAreRemovedOnce() throws Exception {
-        List<String> templateNames = new ArrayList<>();
-
-        // old index templates to be deleted
-        boolean containsWatchesTemplate = randomBoolean();
-        if (containsWatchesTemplate) {
-            templateNames.add("watches");
-        }
-        boolean containsTriggeredWatchesTemplates = randomBoolean();
-        if (containsTriggeredWatchesTemplates) {
-            templateNames.add("triggered_watches");
-        }
-        boolean containsVersionedWatchHistoryTemplate = randomBoolean();
-        if (containsVersionedWatchHistoryTemplate) {
-            templateNames.add("watcher_history_" + randomIntBetween(0, 100));
-        }
-
-        List<String> templatesInClusterState = new ArrayList<>();
-        templatesInClusterState.addAll(Arrays.asList(WatcherIndexTemplateRegistry.HISTORY_TEMPLATE_NAME,
-                WatcherIndexTemplateRegistry.TRIGGERED_TEMPLATE_NAME, WatcherIndexTemplateRegistry.WATCHES_TEMPLATE_NAME));
-        templatesInClusterState.addAll(templateNames);
-        ClusterChangedEvent event = createClusterChangedEvent(templatesInClusterState);
-        registry.clusterChanged(event);
-
-        ArgumentCaptor<DeleteIndexTemplateRequest> requestArgumentCaptor = ArgumentCaptor.forClass(DeleteIndexTemplateRequest.class);
-        verify(client, times(templateNames.size())).execute(anyObject(), requestArgumentCaptor.capture(), anyObject());
-        assertThat(requestArgumentCaptor.getAllValues(), hasSize(templateNames.size()));
-        List<String> deletedTemplateNames = requestArgumentCaptor.getAllValues().stream().map(DeleteIndexTemplateRequest::name)
-                .collect(Collectors.toList());
-        if (containsWatchesTemplate) {
-            assertThat(deletedTemplateNames, hasItem("watches"));
-        }
-        if (containsTriggeredWatchesTemplates) {
-            assertThat(deletedTemplateNames, hasItem("triggered_watches"));
-        }
-        if (containsVersionedWatchHistoryTemplate) {
-            assertThat(deletedTemplateNames, hasItem(startsWith("watcher_history_")));
-        }
-
-        // a second event with removed templates should not trigger any further requests, so the invocation count stays the same
-        ClusterChangedEvent newEvent = createClusterChangedEvent(Arrays.asList(WatcherIndexTemplateRegistry.HISTORY_TEMPLATE_NAME,
-                WatcherIndexTemplateRegistry.TRIGGERED_TEMPLATE_NAME, WatcherIndexTemplateRegistry.WATCHES_TEMPLATE_NAME));
-        registry.clusterChanged(newEvent);
-        verify(client, times(templateNames.size())).execute(anyObject(), anyObject(), anyObject());
-    }
-
     public void testThatNonExistingTemplatesAreAddedImmediately() {
         ClusterChangedEvent event = createClusterChangedEvent(Collections.emptyList());
         registry.clusterChanged(event);