Register CcrRepository based on settings update

server/src/main/java/org/elasticsearch/plugins/RepositoryPlugin.java

@@ -42,4 +42,17 @@ public interface RepositoryPlugin {
     default Map<String, Repository.Factory> getRepositories(Environment env, NamedXContentRegistry namedXContentRegistry) {
         return Collections.emptyMap();
     }
+
+    /**
+     * Returns internal repository types added by this plugin. Internal repositories cannot be registered
+     * through the external API.
+     *
+     * @param env The environment for the local node, which may be used for the local settings and path.repo
+     *
+     * The key of the returned {@link Map} is the type name of the repository and
+     * the value is a factory to construct the {@link Repository} interface.
+     */
+    default Map<String, Repository.Factory> getInternalRepositories(Environment env, NamedXContentRegistry namedXContentRegistry) {
+        return Collections.emptyMap();
+    }
 }

server/src/main/java/org/elasticsearch/repositories/RepositoriesModule.java

@@ -58,8 +58,24 @@ public RepositoriesModule(Environment env, List<RepositoryPlugin> repoPlugins, T
             }
         }
 
+        Map<String, Repository.Factory> internalFactories = new HashMap<>();
+        for (RepositoryPlugin repoPlugin : repoPlugins) {
+            Map<String, Repository.Factory> newRepoTypes = repoPlugin.getInternalRepositories(env, namedXContentRegistry);
+            for (Map.Entry<String, Repository.Factory> entry : newRepoTypes.entrySet()) {
+                if (internalFactories.put(entry.getKey(), entry.getValue()) != null) {
+                    throw new IllegalArgumentException("Internal repository type [" + entry.getKey() + "] is already registered");
+                }
+                if (factories.put(entry.getKey(), entry.getValue()) != null) {
+                    throw new IllegalArgumentException("Internal repository type [" + entry.getKey() + "] is already registered as a " +
+                        "non-internal repository");
+                }
+            }
+        }
+
         Map<String, Repository.Factory> repositoryTypes = Collections.unmodifiableMap(factories);
-        repositoriesService = new RepositoriesService(env.settings(), clusterService, transportService, repositoryTypes, threadPool);
+        Map<String, Repository.Factory> internalRepositoryTypes = Collections.unmodifiableMap(internalFactories);
+        repositoriesService = new RepositoriesService(env.settings(), clusterService, transportService, repositoryTypes,
+            internalRepositoryTypes, threadPool);
     }
 
     @Override

server/src/main/java/org/elasticsearch/repositories/RepositoriesService.java

@@ -36,6 +36,7 @@
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
 import org.elasticsearch.snapshots.RestoreService;
 import org.elasticsearch.snapshots.SnapshotsService;
 import org.elasticsearch.threadpool.ThreadPool;
@@ -57,19 +58,22 @@ public class RepositoriesService implements ClusterStateApplier {
     private static final Logger logger = LogManager.getLogger(RepositoriesService.class);
 
     private final Map<String, Repository.Factory> typesRegistry;
+    private final Map<String, Repository.Factory> internalTypesRegistry;
 
     private final ClusterService clusterService;
 
     private final ThreadPool threadPool;
 
     private final VerifyNodeRepositoryAction verifyAction;
 
+    private final Map<String, Repository> internalRepositories = ConcurrentCollections.newConcurrentMap();
     private volatile Map<String, Repository> repositories = Collections.emptyMap();
 
     public RepositoriesService(Settings settings, ClusterService clusterService, TransportService transportService,
-                               Map<String, Repository.Factory> typesRegistry,
+                               Map<String, Repository.Factory> typesRegistry, Map<String, Repository.Factory> internalTypesRegistry,
                                ThreadPool threadPool) {
         this.typesRegistry = typesRegistry;
+        this.internalTypesRegistry = internalTypesRegistry;
         this.clusterService = clusterService;
         this.threadPool = threadPool;
         // Doesn't make sense to maintain repositories on non-master and non-data nodes
@@ -101,7 +105,7 @@ public void registerRepository(final RegisterRepositoryRequest request, final Ac
 
         // Trying to create the new repository on master to make sure it works
         try {
-            closeRepository(createRepository(newRepositoryMetaData));
+            closeRepository(createRepository(newRepositoryMetaData, typesRegistry));
         } catch (Exception e) {
             registrationListener.onFailure(e);
             return;
@@ -315,7 +319,7 @@ public void applyClusterState(ClusterChangedEvent event) {
                             closeRepository(repository);
                             repository = null;
                             try {
-                                repository = createRepository(repositoryMetaData);
+                                repository = createRepository(repositoryMetaData, typesRegistry);
                             } catch (RepositoryException ex) {
                                 // TODO: this catch is bogus, it means the old repo is already closed,
                                 // but we have nothing to replace it
@@ -324,7 +328,7 @@ public void applyClusterState(ClusterChangedEvent event) {
                         }
                     } else {
                         try {
-                            repository = createRepository(repositoryMetaData);
+                            repository = createRepository(repositoryMetaData, typesRegistry);
                         } catch (RepositoryException ex) {
                             logger.warn(() -> new ParameterizedMessage("failed to create repository [{}]", repositoryMetaData.name()), ex);
                         }
@@ -355,31 +359,59 @@ public Repository repository(String repositoryName) {
         if (repository != null) {
             return repository;
         }
+        repository = internalRepositories.get(repositoryName);
+        if (repository != null) {
+            return repository;
+        }
         throw new RepositoryMissingException(repositoryName);
     }
 
+    public void registerInternalRepository(String name, String type) {
+        RepositoryMetaData metaData = new RepositoryMetaData(name, type, Settings.EMPTY);
+        Repository repository = internalRepositories.computeIfAbsent(name, (n) -> {
+            logger.debug("put internal repository [{}][{}]", name, type);
+            return createRepository(metaData, internalTypesRegistry);
+        });
+        if (type.equals(repository.getMetadata().type()) == false) {
+            logger.warn(new ParameterizedMessage("internal repository [{}][{}] already registered. this prevented the registration of " +
+                "internal repository [{}][{}].", name, repository.getMetadata().type(), name, type));
+        } else if (repositories.containsKey(name)) {
+            logger.warn(new ParameterizedMessage("non-internal repository [{}] already registered. this repository will block the " +
+                "usage of internal repository [{}][{}].", name, metaData.type(), name));
+        }
+    }
+
+    public void unregisterInternalRepository(String name) {
+        Repository repository = internalRepositories.remove(name);
+        if (repository != null) {
+            RepositoryMetaData metadata = repository.getMetadata();
+            logger.debug(() -> new ParameterizedMessage("delete internal repository [{}][{}].", metadata.type(), name));
+            closeRepository(repository);
+        }
+    }
+
     /** Closes the given repository. */
     private void closeRepository(Repository repository) {
         logger.debug("closing repository [{}][{}]", repository.getMetadata().type(), repository.getMetadata().name());
         repository.close();
     }
 
     /**
-     * Creates repository holder
+     * Creates repository holder. This method starts the repository
      */
-    private Repository createRepository(RepositoryMetaData repositoryMetaData) {
+    private Repository createRepository(RepositoryMetaData repositoryMetaData, Map<String, Repository.Factory> factories) {
         logger.debug("creating repository [{}][{}]", repositoryMetaData.type(), repositoryMetaData.name());
-        Repository.Factory factory = typesRegistry.get(repositoryMetaData.type());
+        Repository.Factory factory = factories.get(repositoryMetaData.type());
         if (factory == null) {
             throw new RepositoryException(repositoryMetaData.name(),
                 "repository type [" + repositoryMetaData.type() + "] does not exist");
         }
         try {
-            Repository repository = factory.create(repositoryMetaData, typesRegistry::get);
+            Repository repository = factory.create(repositoryMetaData, factories::get);
             repository.start();
             return repository;
         } catch (Exception e) {
-            logger.warn(() -> new ParameterizedMessage("failed to create repository [{}][{}]", repositoryMetaData.type(), repositoryMetaData.name()), e);
+            logger.warn(new ParameterizedMessage("failed to create repository [{}][{}]", repositoryMetaData.type(), repositoryMetaData.name()), e);
             throw new RepositoryException(repositoryMetaData.name(), "failed to create repository", e);
         }
     }

server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java

@@ -167,7 +167,7 @@ public String getKey(final String key) {
             REMOTE_CLUSTERS_SEEDS);
 
     protected final Settings settings;
-    protected final ClusterNameExpressionResolver clusterNameResolver;
+    private final ClusterNameExpressionResolver clusterNameResolver;
 
     /**
      * Creates a new {@link RemoteClusterAware} instance
@@ -242,14 +242,15 @@ static DiscoveryNode buildSeedNode(String clusterName, String address, boolean p
      * indices per cluster are collected as a list in the returned map keyed by the cluster alias. Local indices are grouped under
      * {@link #LOCAL_CLUSTER_GROUP_KEY}. The returned map is mutable.
      *
+     * @param remoteClusterNames the remote cluster names
      * @param requestIndices the indices in the search request to filter
      * @param indexExists a predicate that can test if a certain index or alias exists in the local cluster
      *
      * @return a map of grouped remote and local indices
      */
-    public Map<String, List<String>> groupClusterIndices(String[] requestIndices, Predicate<String> indexExists) {
+    protected Map<String, List<String>> groupClusterIndices(Set<String> remoteClusterNames, String[] requestIndices,
+                                                            Predicate<String> indexExists) {
         Map<String, List<String>> perClusterIndices = new HashMap<>();
-        Set<String> remoteClusterNames = getRemoteClusterNames();
         for (String index : requestIndices) {
             int i = index.indexOf(RemoteClusterService.REMOTE_CLUSTER_INDEX_SEPARATOR);
             if (i >= 0) {
@@ -281,9 +282,6 @@ public Map<String, List<String>> groupClusterIndices(String[] requestIndices, Pr
         return perClusterIndices;
     }
 
-    protected abstract Set<String> getRemoteClusterNames();
-
-
     /**
      * Subclasses must implement this to receive information about updated cluster aliases. If the given address list is
      * empty the cluster alias is unregistered and should be removed.

server/src/main/java/org/elasticsearch/transport/RemoteClusterService.java

@@ -278,7 +278,7 @@ boolean isRemoteNodeConnected(final String remoteCluster, final DiscoveryNode no
     public Map<String, OriginalIndices> groupIndices(IndicesOptions indicesOptions, String[] indices, Predicate<String> indexExists) {
         Map<String, OriginalIndices> originalIndicesMap = new HashMap<>();
         if (isCrossClusterSearchEnabled()) {
-            final Map<String, List<String>> groupedIndices = groupClusterIndices(indices, indexExists);
+            final Map<String, List<String>> groupedIndices = groupClusterIndices(getRemoteClusterNames(), indices, indexExists);
             if (groupedIndices.isEmpty()) {
                 //search on _all in the local cluster if neither local indices nor remote indices were specified
                 originalIndicesMap.put(LOCAL_CLUSTER_GROUP_KEY, new OriginalIndices(Strings.EMPTY_ARRAY, indicesOptions));
@@ -380,8 +380,7 @@ RemoteClusterConnection getRemoteClusterConnection(String cluster) {
         return connection;
     }
 
-    @Override
-    protected Set<String> getRemoteClusterNames() {
+    Set<String> getRemoteClusterNames() {
         return this.remoteClusters.keySet();
     }
 

server/src/test/java/org/elasticsearch/indices/cluster/IndicesClusterStateServiceRandomUpdatesTests.java

@@ -461,7 +461,7 @@ private IndicesClusterStateService createIndicesClusterStateService(DiscoveryNod
             Collections.emptySet());
         final ClusterService clusterService = mock(ClusterService.class);
         final RepositoriesService repositoriesService = new RepositoriesService(settings, clusterService,
-            transportService, null, threadPool);
+            transportService, Collections.emptyMap(), Collections.emptyMap(), threadPool);
         final PeerRecoveryTargetService recoveryTargetService = new PeerRecoveryTargetService(threadPool,
             transportService, null, clusterService);
         final ShardStateAction shardStateAction = mock(ShardStateAction.class);

server/src/test/java/org/elasticsearch/repositories/RepositoriesModuleTests.java

@@ -0,0 +1,101 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you 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 org.elasticsearch.repositories;
+
+import org.elasticsearch.cluster.service.ClusterService;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
+import org.elasticsearch.env.Environment;
+import org.elasticsearch.plugins.RepositoryPlugin;
+import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.transport.TransportService;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class RepositoriesModuleTests extends ESTestCase {
+
+    private Environment environment;
+    private NamedXContentRegistry contentRegistry;
+    private List<RepositoryPlugin> repoPlugins = new ArrayList<>();
+    private RepositoryPlugin plugin1;
+    private RepositoryPlugin plugin2;
+    private Repository.Factory factory;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        environment = mock(Environment.class);
+        contentRegistry = mock(NamedXContentRegistry.class);
+        plugin1 = mock(RepositoryPlugin.class);
+        plugin2 = mock(RepositoryPlugin.class);
+        factory = mock(Repository.Factory.class);
+        repoPlugins.add(plugin1);
+        repoPlugins.add(plugin2);
+        when(environment.settings()).thenReturn(Settings.EMPTY);
+    }
+
+    public void testCanRegisterTwoRepositoriesWithDifferentTypes() {
+        when(plugin1.getRepositories(environment, contentRegistry)).thenReturn(Collections.singletonMap("type1", factory));
+        when(plugin2.getRepositories(environment, contentRegistry)).thenReturn(Collections.singletonMap("type2", factory));
+
+        // Would throw
+        new RepositoriesModule(environment, repoPlugins, mock(TransportService.class), mock(ClusterService.class),
+            mock(ThreadPool.class), contentRegistry);
+    }
+
+    public void testCannotRegisterTwoRepositoriesWithSameTypes() {
+        when(plugin1.getRepositories(environment, contentRegistry)).thenReturn(Collections.singletonMap("type1", factory));
+        when(plugin2.getRepositories(environment, contentRegistry)).thenReturn(Collections.singletonMap("type1", factory));
+
+        IllegalArgumentException ex = expectThrows(IllegalArgumentException.class,
+            () -> new RepositoriesModule(environment, repoPlugins, mock(TransportService.class), mock(ClusterService.class),
+                mock(ThreadPool.class), contentRegistry));
+
+        assertEquals("Repository type [type1] is already registered", ex.getMessage());
+    }
+
+    public void testCannotRegisterTwoInternalRepositoriesWithSameTypes() {
+        when(plugin1.getInternalRepositories(environment, contentRegistry)).thenReturn(Collections.singletonMap("type1", factory));
+        when(plugin2.getInternalRepositories(environment, contentRegistry)).thenReturn(Collections.singletonMap("type1", factory));
+
+        IllegalArgumentException ex = expectThrows(IllegalArgumentException.class,
+            () -> new RepositoriesModule(environment, repoPlugins, mock(TransportService.class), mock(ClusterService.class),
+                mock(ThreadPool.class), contentRegistry));
+
+        assertEquals("Internal repository type [type1] is already registered", ex.getMessage());
+    }
+
+    public void testCannotRegisterNormalAndInternalRepositoriesWithSameTypes() {
+        when(plugin1.getRepositories(environment, contentRegistry)).thenReturn(Collections.singletonMap("type1", factory));
+        when(plugin2.getInternalRepositories(environment, contentRegistry)).thenReturn(Collections.singletonMap("type1", factory));
+
+        IllegalArgumentException ex = expectThrows(IllegalArgumentException.class,
+            () -> new RepositoriesModule(environment, repoPlugins, mock(TransportService.class), mock(ClusterService.class),
+                mock(ThreadPool.class), contentRegistry));
+
+        assertEquals("Internal repository type [type1] is already registered as a non-internal repository", ex.getMessage());
+    }
+}