refactor code for better extensibility in future

Signed-off-by: bansvaru <[email protected]>

server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java

@@ -106,11 +106,10 @@ public void testFullClusterRestoreStaleDelete() throws Exception {
             );
         }
 
-        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestMetadata(
+        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestClusterState(
             cluster().getClusterName(),
-            getClusterState().metadata().clusterUUID(),
-            clusterMetadataManifest.get()
-        ).getIndices();
+            getClusterState().metadata().clusterUUID()
+        ).getMetadata().getIndices();
         assertEquals(0, indexMetadataMap.values().stream().findFirst().get().getNumberOfReplicas());
         assertEquals(shardCount, indexMetadataMap.values().stream().findFirst().get().getNumberOfShards());
     }

server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java

@@ -754,25 +754,33 @@ private IndexMetadata getIndexMetadata(String clusterName, String clusterUUID, U
     }
 
     /**
-     * Fetch latest metadata from remote cluster state including global metadata and index metadata
+     * Fetch latest ClusterState from remote, including global metadata, index metadata and cluster state version
      *
      * @param clusterUUID uuid of cluster state to refer to in remote
      * @param clusterName name of the cluster
      * @return {@link IndexMetadata}
      */
-    public Metadata getLatestMetadata(String clusterName, String clusterUUID, ClusterMetadataManifest clusterMetadataManifest) {
+    public ClusterState getLatestClusterState(String clusterName, String clusterUUID) {
         start();
-
+        Optional<ClusterMetadataManifest> clusterMetadataManifest = getLatestClusterMetadataManifest(clusterName, clusterUUID);
+        if (clusterMetadataManifest.isEmpty()) {
+            throw new IllegalStateException(
+                String.format(Locale.ROOT, "Latest cluster metadata manifest is not present for the provided clusterUUID: %s", clusterUUID)
+            );
+        }
         // Fetch Global Metadata
-        Metadata globalMetadata = getGlobalMetadata(clusterName, clusterUUID, clusterMetadataManifest);
+        Metadata globalMetadata = getGlobalMetadata(clusterName, clusterUUID, clusterMetadataManifest.get());
 
         // Fetch Index Metadata
-        Map<String, IndexMetadata> indices = getIndexMetadataMap(clusterName, clusterUUID, clusterMetadataManifest);
+        Map<String, IndexMetadata> indices = getIndexMetadataMap(clusterName, clusterUUID, clusterMetadataManifest.get());
 
         Map<String, IndexMetadata> indexMetadataMap = new HashMap<>();
         indices.values().forEach(indexMetadata -> { indexMetadataMap.put(indexMetadata.getIndex().getName(), indexMetadata); });
 
-        return Metadata.builder(globalMetadata).indices(indexMetadataMap).build();
+        return ClusterState.builder(ClusterState.EMPTY_STATE)
+            .version(clusterMetadataManifest.get().getStateVersion())
+            .metadata(Metadata.builder(globalMetadata).indices(indexMetadataMap).build())
+            .build();
     }
 
     private Metadata getGlobalMetadata(String clusterName, String clusterUUID, ClusterMetadataManifest clusterMetadataManifest) {

server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java

@@ -32,7 +32,6 @@
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.shard.ShardId;
-import org.opensearch.gateway.remote.ClusterMetadataManifest;
 import org.opensearch.gateway.remote.RemoteClusterStateService;
 import org.opensearch.indices.ShardLimitValidator;
 import org.opensearch.repositories.IndexId;
@@ -139,7 +138,7 @@ public RemoteRestoreResult restore(
         String[] indexNames
     ) {
         Map<String, Tuple<Boolean, IndexMetadata>> indexMetadataMap = new HashMap<>();
-        Metadata remoteMetadata = null;
+        ClusterState remoteState = null;
         boolean metadataFromRemoteStore = (restoreClusterUUID == null
             || restoreClusterUUID.isEmpty()
             || restoreClusterUUID.isBlank()) == false;
@@ -150,25 +149,8 @@ public RemoteRestoreResult restore(
                 if (currentState.metadata().clusterUUID().equals(restoreClusterUUID)) {
                     throw new IllegalArgumentException("clusterUUID to restore from should be different from current cluster UUID");
                 }
-                Optional<ClusterMetadataManifest> clusterMetadataManifest = remoteClusterStateService.getLatestClusterMetadataManifest(
-                    currentState.getClusterName().value(),
-                    restoreClusterUUID
-                );
-                if (clusterMetadataManifest.isEmpty()) {
-                    throw new IllegalStateException(
-                        String.format(
-                            Locale.ROOT,
-                            "Latest cluster metadata manifest is not present for the provided clusterUUID: %s",
-                            restoreClusterUUID
-                        )
-                    );
-                }
-                remoteMetadata = remoteClusterStateService.getLatestMetadata(
-                    currentState.getClusterName().value(),
-                    restoreClusterUUID,
-                    clusterMetadataManifest.get()
-                );
-                remoteMetadata.getIndices().values().forEach(indexMetadata -> {
+                remoteState = remoteClusterStateService.getLatestClusterState(currentState.getClusterName().value(), restoreClusterUUID);
+                remoteState.getMetadata().getIndices().values().forEach(indexMetadata -> {
                     indexMetadataMap.put(indexMetadata.getIndex().getName(), new Tuple<>(true, indexMetadata));
                 });
             } catch (Exception e) {
@@ -194,7 +176,7 @@ public RemoteRestoreResult restore(
                 }
             }
         }
-        return executeRestore(currentState, indexMetadataMap, restoreAllShards, remoteMetadata);
+        return executeRestore(currentState, indexMetadataMap, restoreAllShards, remoteState);
     }
 
     /**
@@ -208,7 +190,7 @@ private RemoteRestoreResult executeRestore(
         ClusterState currentState,
         Map<String, Tuple<Boolean, IndexMetadata>> indexMetadataMap,
         boolean restoreAllShards,
-        Metadata remoteMetadata
+        ClusterState remoteState
     ) {
         final String restoreUUID = UUIDs.randomBase64UUID();
         List<String> indicesToBeRestored = new ArrayList<>();
@@ -258,8 +240,9 @@ private RemoteRestoreResult executeRestore(
             totalShards += updatedIndexMetadata.getNumberOfShards();
         }
 
-        if (remoteMetadata != null) {
-            restoreGlobalMetadata(mdBuilder, remoteMetadata);
+        if (remoteState != null) {
+            restoreGlobalMetadata(mdBuilder, remoteState.getMetadata());
+            builder.version(remoteState.version());
         }
 
         RestoreInfo restoreInfo = new RestoreInfo("remote_store", indicesToBeRestored, totalShards, totalShards);
@@ -273,7 +256,6 @@ private RemoteRestoreResult executeRestore(
     }
 
     private void restoreGlobalMetadata(Metadata.Builder mdBuilder, Metadata remoteMetadata) {
-        mdBuilder.version(remoteMetadata.version());
         if (remoteMetadata.persistentSettings() != null) {
             Settings settings = remoteMetadata.persistentSettings();
             clusterService.getClusterSettings().validateUpdate(settings);

server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java

@@ -659,11 +659,10 @@ public void testReadLatestMetadataManifestSuccessButNoIndexMetadata() throws IOE
 
         remoteClusterStateService.start();
         assertEquals(
-            remoteClusterStateService.getLatestMetadata(
-                clusterState.getClusterName().value(),
-                clusterState.metadata().clusterUUID(),
-                expectedManifest
-            ).getIndices().size(),
+            remoteClusterStateService.getLatestClusterState(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID())
+                .getMetadata()
+                .getIndices()
+                .size(),
             0
         );
     }
@@ -690,11 +689,10 @@ public void testReadLatestMetadataManifestSuccessButIndexMetadataFetchIOExceptio
         remoteClusterStateService.start();
         Exception e = assertThrows(
             IllegalStateException.class,
-            () -> remoteClusterStateService.getLatestMetadata(
+            () -> remoteClusterStateService.getLatestClusterState(
                 clusterState.getClusterName().value(),
-                clusterState.metadata().clusterUUID(),
-                expectedManifest
-            ).getIndices()
+                clusterState.metadata().clusterUUID()
+            ).getMetadata().getIndices()
         );
         assertEquals(e.getMessage(), "Error while downloading IndexMetadata - " + uploadedIndexMetadata.getUploadedFilename());
     }
@@ -755,11 +753,10 @@ public void testReadGlobalMetadata() throws IOException {
         Metadata expactedMetadata = Metadata.builder().persistentSettings(Settings.builder().put("readonly", true).build()).build();
         mockBlobContainerForGlobalMetadata(mockBlobStoreObjects(), expectedManifest, expactedMetadata);
 
-        Metadata metadata = remoteClusterStateService.getLatestMetadata(
+        Metadata metadata = remoteClusterStateService.getLatestClusterState(
             clusterState.getClusterName().value(),
-            clusterState.metadata().clusterUUID(),
-            expectedManifest
-        );
+            clusterState.metadata().clusterUUID()
+        ).getMetadata();
 
         assertTrue(Metadata.isGlobalStateEquals(metadata, expactedMetadata));
     }
@@ -793,10 +790,9 @@ public void testReadGlobalMetadataIOException() throws IOException {
         remoteClusterStateService.start();
         Exception e = assertThrows(
             IllegalStateException.class,
-            () -> remoteClusterStateService.getLatestMetadata(
+            () -> remoteClusterStateService.getLatestClusterState(
                 clusterState.getClusterName().value(),
-                clusterState.metadata().clusterUUID(),
-                expectedManifest
+                clusterState.metadata().clusterUUID()
             )
         );
         assertEquals(e.getMessage(), "Error while downloading Global Metadata - " + globalIndexMetadataName);
@@ -828,17 +824,15 @@ public void testReadLatestIndexMetadataSuccess() throws IOException {
             .nodeId("nodeA")
             .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
             .previousClusterUUID("prev-cluster-uuid")
-            // .globalMetadataFileName("global-metadata-file")
             .codecVersion(ClusterMetadataManifest.CODEC_V0)
             .build();
 
         mockBlobContainer(mockBlobStoreObjects(), expectedManifest, Map.of(index.getUUID(), indexMetadata));
 
-        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestMetadata(
+        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestClusterState(
             clusterState.getClusterName().value(),
-            clusterState.metadata().clusterUUID(),
-            expectedManifest
-        ).getIndices();
+            clusterState.metadata().clusterUUID()
+        ).getMetadata().getIndices();
 
         assertEquals(indexMetadataMap.size(), 1);
         assertEquals(indexMetadataMap.get(index.getName()).getIndex().getName(), index.getName());