Revert "Remove RestGetAllAliasesAction (#31308)"

This reverts commit 38b1a5f.

Relates to #31516

Author: javanna

server/src/main/java/org/elasticsearch/action/ActionModule.java

@@ -257,6 +257,7 @@
 import org.elasticsearch.rest.action.admin.indices.RestFlushAction;
 import org.elasticsearch.rest.action.admin.indices.RestForceMergeAction;
 import org.elasticsearch.rest.action.admin.indices.RestGetAliasesAction;
+import org.elasticsearch.rest.action.admin.indices.RestGetAllAliasesAction;
 import org.elasticsearch.rest.action.admin.indices.RestGetFieldMappingAction;
 import org.elasticsearch.rest.action.admin.indices.RestGetIndexTemplateAction;
 import org.elasticsearch.rest.action.admin.indices.RestGetIndicesAction;
@@ -557,6 +558,8 @@ public void initRestHandlers(Supplier<DiscoveryNodes> nodesInCluster) {
         registerHandler.accept(new RestRestoreSnapshotAction(settings, restController));
         registerHandler.accept(new RestDeleteSnapshotAction(settings, restController));
         registerHandler.accept(new RestSnapshotsStatusAction(settings, restController));
+
+        registerHandler.accept(new RestGetAllAliasesAction(settings, restController));
         registerHandler.accept(new RestGetIndicesAction(settings, restController, indexScopedSettings, settingsFilter));
         registerHandler.accept(new RestIndicesStatsAction(settings, restController));
         registerHandler.accept(new RestIndicesSegmentsAction(settings, restController));

server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestGetAliasesAction.java

@@ -60,8 +60,6 @@ public class RestGetAliasesAction extends BaseRestHandler {
 
     public RestGetAliasesAction(final Settings settings, final RestController controller) {
         super(settings);
-        controller.registerHandler(GET, "/_alias", this);
-        controller.registerHandler(GET, "/_aliases", this);
         controller.registerHandler(GET, "/_alias/{name}", this);
         controller.registerHandler(HEAD, "/_alias/{name}", this);
         controller.registerHandler(GET, "/{index}/_alias", this);

server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestGetAllAliasesAction.java

@@ -0,0 +1,103 @@
+/*
+ * 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.rest.action.admin.indices;
+
+import org.elasticsearch.action.admin.indices.get.GetIndexRequest;
+import org.elasticsearch.action.admin.indices.get.GetIndexRequest.Feature;
+import org.elasticsearch.action.admin.indices.get.GetIndexResponse;
+import org.elasticsearch.action.support.IndicesOptions;
+import org.elasticsearch.client.node.NodeClient;
+import org.elasticsearch.cluster.metadata.AliasMetaData;
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.ToXContent.Params;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.rest.BaseRestHandler;
+import org.elasticsearch.rest.BytesRestResponse;
+import org.elasticsearch.rest.RestController;
+import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.RestResponse;
+import org.elasticsearch.rest.action.RestBuilderListener;
+
+import java.io.IOException;
+import java.util.List;
+
+import static org.elasticsearch.rest.RestRequest.Method.GET;
+import static org.elasticsearch.rest.RestStatus.OK;
+
+/**
+ * The REST handler for retrieving all aliases
+ */
+public class RestGetAllAliasesAction extends BaseRestHandler {
+
+    public RestGetAllAliasesAction(final Settings settings, final RestController controller) {
+        super(settings);
+        controller.registerHandler(GET, "/_alias", this);
+        controller.registerHandler(GET, "/_aliases", this);
+    }
+
+    @Override
+    public String getName() {
+        return "get_all_aliases_action";
+    }
+
+    @Override
+    public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
+        final GetIndexRequest getIndexRequest = new GetIndexRequest();
+        getIndexRequest.indices(Strings.EMPTY_ARRAY);
+        getIndexRequest.features(Feature.ALIASES);
+        getIndexRequest.indicesOptions(IndicesOptions.fromRequest(request, getIndexRequest.indicesOptions()));
+        getIndexRequest.local(request.paramAsBoolean("local", getIndexRequest.local()));
+        getIndexRequest.humanReadable(request.paramAsBoolean("human", false));
+        return channel -> client.admin().indices().getIndex(getIndexRequest, new RestBuilderListener<GetIndexResponse>(channel) {
+
+            @Override
+            public RestResponse buildResponse(final GetIndexResponse response, final XContentBuilder builder) throws Exception {
+                builder.startObject();
+                {
+                    for (final String index : response.indices()) {
+                        builder.startObject(index);
+                        {
+                            writeAliases(response.aliases().get(index), builder, request);
+                        }
+                        builder.endObject();
+                    }
+                }
+                builder.endObject();
+
+                return new BytesRestResponse(OK, builder);
+            }
+
+            private void writeAliases(final List<AliasMetaData> aliases, final XContentBuilder builder,
+                                      final Params params) throws IOException {
+                builder.startObject("aliases");
+                {
+                    if (aliases != null) {
+                        for (final AliasMetaData alias : aliases) {
+                            AliasMetaData.Builder.toXContent(alias, builder, params);
+                        }
+                    }
+                }
+                builder.endObject();
+            }
+        });
+    }
+
+}

x-pack/qa/core-rest-tests-with-security/build.gradle

@@ -15,7 +15,6 @@ integTestRunner {
     ['cat.aliases/10_basic/Empty cluster',
      'index/10_with_id/Index with ID',
      'indices.get_alias/10_basic/Get alias against closed indices',
-     'indices.get_alias/20_empty/Check empty aliases when getting all aliases via /_alias',
      'cat.templates/10_basic/No templates',
      'cat.templates/10_basic/Sort templates',
      'cat.templates/10_basic/Multiple template',