Allow setting of copy_settings in the HLRC (#39752)

#30255 introduced the `copy_settings` parameter in 6.x.
This commit adds support for setting it via `setCopySettings` in the
HLRC and also adjusts docs.

Author: dliappis

client/rest-high-level/src/main/java/org/elasticsearch/client/IndicesRequestConverters.java

@@ -342,6 +342,7 @@ private static Request resize(ResizeRequest resizeRequest) throws IOException {
         params.withTimeout(resizeRequest.timeout());
         params.withMasterTimeout(resizeRequest.masterNodeTimeout());
         params.withWaitForActiveShards(resizeRequest.getTargetIndexRequest().waitForActiveShards(), ActiveShardCount.DEFAULT);
+        params.withCopySettings(resizeRequest.getCopySettings());
 
         request.setEntity(RequestConverters.createEntity(resizeRequest, RequestConverters.REQUEST_BODY_CONTENT_TYPE));
         return request;

client/rest-high-level/src/main/java/org/elasticsearch/client/RequestConverters.java

@@ -909,6 +909,17 @@ Params withWaitForActiveShards(ActiveShardCount activeShardCount) {
             return withWaitForActiveShards(activeShardCount, ActiveShardCount.DEFAULT);
         }
 
+        /**
+         * @deprecated <code>copy_settings</code> can not be set to false. If unset, behaves as <code>false</code> and won't copy settings.
+         */
+        @Deprecated
+        Params withCopySettings(Boolean setCopySettings) {
+            if (setCopySettings != null) {
+                return putParam("copy_settings", setCopySettings.toString());
+            }
+            return this;
+        }
+
         Params withIndicesOptions(IndicesOptions indicesOptions) {
             if (indicesOptions != null) {
                 withIgnoreUnavailable(indicesOptions.ignoreUnavailable());

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

@@ -868,6 +868,12 @@ private void resizeTest(ResizeType resizeType, CheckedFunction<ResizeRequest, Re
         ResizeRequest resizeRequest = new ResizeRequest(indices[0], indices[1]);
         resizeRequest.setResizeType(resizeType);
         Map<String, String> expectedParams = new HashMap<>();
+
+        if (randomBoolean()) {
+            resizeRequest.setCopySettings(true);
+            expectedParams.put("copy_settings", "true");
+        }
+
         RequestConvertersTests.setRandomMasterTimeout(resizeRequest, expectedParams);
         RequestConvertersTests.setRandomTimeout(resizeRequest::timeout, resizeRequest.timeout(), expectedParams);
 

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

@@ -1683,9 +1683,13 @@ public void testShrinkIndex() throws Exception {
         request.setWaitForActiveShards(2); // <1>
         request.setWaitForActiveShards(ActiveShardCount.DEFAULT); // <2>
         // end::shrink-index-request-waitForActiveShards
+        // tag::shrink-index-request-copySettings
+        request.setCopySettings(true); // <1>
+        // end::shrink-index-request-copySettings
         // tag::shrink-index-request-settings
         request.getTargetIndexRequest().settings(Settings.builder()
-                .put("index.number_of_shards", 2)); // <1>
+                .put("index.number_of_shards", 2) // <1>
+                .putNull("index.routing.allocation.require._name")); // <2>
         // end::shrink-index-request-settings
         // tag::shrink-index-request-aliases
         request.getTargetIndexRequest().alias(new Alias("target_alias")); // <1>

docs/java-rest/high-level/indices/shrink_index.asciidoc

@@ -47,12 +47,21 @@ returns a response, as an `int`
 <2> The number of active shard copies to wait for before the shrink index API
 returns a response, as an `ActiveShardCount`
 
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-request-copySettings]
+--------------------------------------------------
+<1> Use `true` to copy the settings from the source index to the target
+index. This cannot be `false`. If this method is not used, default behavior is
+not to copy. This parameter will be removed in 8.0.0.
+
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------
 include-tagged::{doc-tests-file}[{api}-request-settings]
 --------------------------------------------------
 <1> The settings to apply to the target index, which include the number of
 shards to create for it
+<2> Remove the allocation requirement copied from the source index
 
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------