Implemented XContent serialisation for GetIndexResponse (#31675)

This PR does the server side work for adding the Get Index API to the REST
high-level-client, namely moving resolving default settings to the
transport action. A follow up would be the client side changes.

build.gradle

@@ -170,8 +170,8 @@ task verifyVersions {
  * the enabled state of every bwc task. It should be set back to true
  * after the backport of the backcompat code is complete.
  */
-final boolean bwc_tests_enabled = true
-final String bwc_tests_disabled_issue = "" /* place a PR link here when commiting bwc changes */
+final boolean bwc_tests_enabled = false
+final String bwc_tests_disabled_issue = "https://github.com/elastic/elasticsearch/pull/31675" /* place a PR link here when commiting bwc changes */
 if (bwc_tests_enabled == false) {
   if (bwc_tests_disabled_issue.isEmpty()) {
     throw new GradleException("bwc_tests_disabled_issue must be set when bwc_tests_enabled == false")

client/rest-high-level/src/test/java/org/elasticsearch/client/GetAliasesResponseTests.java

@@ -59,7 +59,7 @@ private static Map<String, Set<AliasMetaData>> createIndicesAliasesMap(int min,
         return map;
     }
 
-    private static AliasMetaData createAliasMetaData() {
+    public static AliasMetaData createAliasMetaData() {
         AliasMetaData.Builder builder = AliasMetaData.builder(randomAlphaOfLengthBetween(3, 10));
         if (randomBoolean()) {
             builder.routing(randomAlphaOfLengthBetween(3, 10));

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

@@ -557,7 +557,7 @@ 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 RestGetIndicesAction(settings, restController, indexScopedSettings, settingsFilter));
+        registerHandler.accept(new RestGetIndicesAction(settings, restController));
         registerHandler.accept(new RestIndicesStatsAction(settings, restController));
         registerHandler.accept(new RestIndicesSegmentsAction(settings, restController));
         registerHandler.accept(new RestIndicesShardStoresAction(settings, restController));

server/src/main/java/org/elasticsearch/action/admin/indices/get/GetIndexRequest.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.action.admin.indices.get;
 
+import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.support.master.info.ClusterInfoRequest;
 import org.elasticsearch.common.io.stream.StreamInput;
@@ -80,6 +81,9 @@ public GetIndexRequest(StreamInput in) throws IOException {
             features[i] = Feature.fromId(in.readByte());
         }
         humanReadable = in.readBoolean();
+        if (in.getVersion().onOrAfter(Version.V_6_4_0)) {
+            includeDefaults = in.readBoolean();
+        }
     }
 
     public GetIndexRequest features(Feature... features) {
@@ -119,8 +123,7 @@ public boolean humanReadable() {
 
     /**
      * Sets the value of "include_defaults".
-     * Used only by the high-level REST client.
-     * 
+     *
      * @param includeDefaults value of "include_defaults" to be set.
      * @return this request
      */
@@ -131,8 +134,7 @@ public GetIndexRequest includeDefaults(boolean includeDefaults) {
 
     /**
      * Whether to return all default settings for each of the indices.
-     * Used only by the high-level REST client.
-     * 
+     *
      * @return <code>true</code> if defaults settings for each of the indices need to returned;
      * <code>false</code> otherwise.
      */
@@ -153,6 +155,9 @@ public void writeTo(StreamOutput out) throws IOException {
             out.writeByte(feature.id);
         }
         out.writeBoolean(humanReadable);
+        if (out.getVersion().onOrAfter(Version.V_6_4_0)) {
+            out.writeBoolean(includeDefaults);
+        }
     }
 
 }