Add UTs

Signed-off-by: Arpit Bandejiya <abandeji@amazon.com>

server/src/test/java/org/opensearch/cluster/routing/remote/RemoteRoutingTableServiceTests.java

@@ -0,0 +1,187 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.cluster.routing.remote;
+
+import org.junit.After;
+import org.junit.Before;
+import org.opensearch.Version;
+import org.opensearch.cluster.ClusterName;
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.routing.IndexRoutingTable;
+import org.opensearch.cluster.routing.RoutingTable;
+import org.opensearch.cluster.routing.remote.RemoteRoutingTableService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
+import org.opensearch.core.index.Index;
+import org.opensearch.repositories.FilterRepository;
+import org.opensearch.repositories.RepositoriesService;
+import org.opensearch.repositories.RepositoryMissingException;
+import org.opensearch.repositories.blobstore.BlobStoreRepository;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.function.Supplier;
+
+import static org.mockito.Mockito.*;
+import static org.opensearch.common.util.FeatureFlags.REMOTE_ROUTING_TABLE_EXPERIMENTAL;
+import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_ROUTING_TABLE_REPOSITORY_NAME_ATTRIBUTE_KEY;
+
+public class RemoteRoutingTableServiceTests extends OpenSearchTestCase {
+
+    private RemoteRoutingTableService remoteRoutingTableService;
+    private ClusterSettings clusterSettings;
+    private Supplier<RepositoriesService> repositoriesServiceSupplier;
+    private RepositoriesService repositoriesService;
+    private BlobStoreRepository blobStoreRepository;
+    private final ThreadPool threadPool = new TestThreadPool(getClass().getName());
+
+    @Before
+    public void setup() {
+        repositoriesServiceSupplier = mock(Supplier.class);
+        repositoriesService = mock(RepositoriesService.class);
+        when(repositoriesServiceSupplier.get()).thenReturn(repositoriesService);
+
+        Settings settings = Settings.builder()
+            .put(RemoteRoutingTableService.REMOTE_ROUTING_TABLE_ENABLED_SETTING.getKey(), true)
+            .put("node.attr." + REMOTE_STORE_ROUTING_TABLE_REPOSITORY_NAME_ATTRIBUTE_KEY, "routing_repository")
+            .build();
+
+        clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+
+        blobStoreRepository = mock(BlobStoreRepository.class);
+        when(repositoriesService.repository("routing_repository")).thenReturn(blobStoreRepository);
+
+        Settings nodeSettings = Settings.builder().put(REMOTE_ROUTING_TABLE_EXPERIMENTAL, "true").build();
+        FeatureFlags.initializeFeatureFlags(nodeSettings);
+
+        remoteRoutingTableService = new RemoteRoutingTableService(
+            repositoriesServiceSupplier,
+            settings,
+            threadPool
+        );
+    }
+
+    @After
+    public void teardown() throws Exception {
+        super.tearDown();
+        remoteRoutingTableService.close();
+        threadPool.shutdown();
+    }
+
+
+    public void testFailInitializationWhenRemoteRoutingDisabled() {
+        final Settings settings = Settings.builder().build();
+        assertThrows(
+            AssertionError.class,
+            () -> new RemoteRoutingTableService(
+                repositoriesServiceSupplier,
+                settings,
+                new ThreadPool(settings)
+            )
+        );
+    }
+
+
+    public void testFailStartWhenNotBlobRepository() {
+        final FilterRepository filterRepository = mock(FilterRepository.class);
+        when(repositoriesService.repository("routing_repository")).thenReturn(filterRepository);
+        assertThrows(AssertionError.class, () -> remoteRoutingTableService.start());
+    }
+
+    public void testGetChangedIndicesRouting() {
+        String indexName = randomAlphaOfLength(randomIntBetween(1, 50));
+        final Index index = new Index(indexName, "uuid");
+        final IndexMetadata indexMetadata = new IndexMetadata.Builder(indexName).settings(
+            Settings.builder()
+                .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
+                .put(IndexMetadata.SETTING_INDEX_UUID, "uuid")
+                .build()
+        ).numberOfShards(1).numberOfReplicas(1).build();
+
+        RoutingTable routingTable = RoutingTable.builder().addAsNew(indexMetadata).build();
+        ClusterState state = ClusterState.builder(ClusterName.DEFAULT).routingTable(routingTable).build();
+
+        assertEquals(0, RemoteRoutingTableService.getIndicesRoutingMapDiff(state.getRoutingTable(), state.getRoutingTable()).getUpserts().size());
+
+        //Reversing order to check for equality without order.
+        IndexRoutingTable indexRouting = routingTable.getIndicesRouting().get(indexName);
+        IndexRoutingTable indexRoutingTable = IndexRoutingTable.builder(index).addShard(indexRouting.getShards().get(0).replicaShards().get(0))
+            .addShard(indexRouting.getShards().get(0).primaryShard()).build();
+        ClusterState newState = ClusterState.builder(ClusterName.DEFAULT).routingTable(RoutingTable.builder().add(indexRoutingTable).build()).build();
+        assertEquals(0, RemoteRoutingTableService.getIndicesRoutingMapDiff(state.getRoutingTable(), newState.getRoutingTable()).getUpserts().size());
+    }
+
+    public void testIndicesRoutingDiffWhenIndexDeleted() {
+
+        ClusterState state = createIndices(randomIntBetween(1,100));
+        RoutingTable routingTable = state.routingTable();
+
+        List<String> allIndices = new ArrayList<>();
+        routingTable.getIndicesRouting().forEach((k,v) -> allIndices.add(k));
+
+        String indexNameToDelete = allIndices.get(randomIntBetween(0, allIndices.size()-1));
+        RoutingTable updatedRoutingTable = RoutingTable.builder(routingTable).remove(indexNameToDelete).build();
+
+        assertEquals(1, RemoteRoutingTableService.getIndicesRoutingMapDiff(state.getRoutingTable(), updatedRoutingTable).getDeletes().size());
+        assertEquals(indexNameToDelete, RemoteRoutingTableService.getIndicesRoutingMapDiff(state.getRoutingTable(), updatedRoutingTable).getDeletes().get(0));
+    }
+
+    public void testIndicesRoutingDiffWhenIndexDeletedAndAdded() {
+
+        ClusterState state = createIndices(randomIntBetween(1,100));
+        RoutingTable routingTable = state.routingTable();
+
+        List<String> allIndices = new ArrayList<>();
+        routingTable.getIndicesRouting().forEach((k,v) -> allIndices.add(k));
+
+        String indexNameToDelete = allIndices.get(randomIntBetween(0, allIndices.size()-1));
+        RoutingTable.Builder updatedRoutingTableBuilder = RoutingTable.builder(routingTable).remove(indexNameToDelete);
+
+        String indexName = randomAlphaOfLength(randomIntBetween(1, 50));
+        final IndexMetadata indexMetadata = new IndexMetadata.Builder(indexName).settings(
+            Settings.builder()
+                .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
+                .put(IndexMetadata.SETTING_INDEX_UUID, "uuid")
+                .build()
+        ).numberOfShards(1).numberOfReplicas(1).build();
+
+        RoutingTable updatedRoutingTable =  updatedRoutingTableBuilder.addAsNew(indexMetadata).build();
+
+        assertEquals(1, RemoteRoutingTableService.getIndicesRoutingMapDiff(state.getRoutingTable(), updatedRoutingTable).getDeletes().size());
+        assertEquals(indexNameToDelete, RemoteRoutingTableService.getIndicesRoutingMapDiff(state.getRoutingTable(), updatedRoutingTable).getDeletes().get(0));
+
+        assertEquals(1, RemoteRoutingTableService.getIndicesRoutingMapDiff(state.getRoutingTable(), updatedRoutingTable).getUpserts().size());
+        assertTrue(RemoteRoutingTableService.getIndicesRoutingMapDiff(state.getRoutingTable(), updatedRoutingTable).getUpserts().containsKey(indexName));
+    }
+
+    private ClusterState createIndices(int numberOfIndices) {
+        RoutingTable.Builder routingTableBuilder = RoutingTable.builder();
+        for(int i=0; i< numberOfIndices; i++) {
+            String indexName = randomAlphaOfLength(randomIntBetween(1, 50));
+            final Index index = new Index(indexName, "uuid");
+            final IndexMetadata indexMetadata = new IndexMetadata.Builder(indexName).settings(
+                Settings.builder()
+                    .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
+                    .put(IndexMetadata.SETTING_INDEX_UUID, "uuid")
+                    .build()
+            ).numberOfShards(1).numberOfReplicas(1).build();
+
+            routingTableBuilder.addAsNew(indexMetadata);
+        }
+        return ClusterState.builder(ClusterName.DEFAULT).routingTable(routingTableBuilder.build()).build();
+    }
+}