rest-high-level: added get cluster settings (#31706)

Relates to #27205

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

@@ -23,6 +23,8 @@
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthRequest;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
+import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsRequest;
+import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsResponse;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsResponse;
 import org.elasticsearch.rest.RestStatus;
@@ -100,6 +102,35 @@ public void putSettingsAsync(ClusterUpdateSettingsRequest clusterUpdateSettingsR
                 ClusterUpdateSettingsResponse::fromXContent, listener, emptySet(), headers);
     }
 
+    /**
+     * Get the cluster wide settings using the Cluster Get Settings API.
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-get-settings.html"> Cluster Get Settings
+     * API on elastic.co</a>
+     * @param clusterGetSettingsRequest the request
+     * @param options the request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     * @return the response
+     * @throws IOException in case there is a problem sending the request or parsing back the response
+     */
+    public ClusterGetSettingsResponse getSettings(ClusterGetSettingsRequest clusterGetSettingsRequest, RequestOptions options)
+        throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(clusterGetSettingsRequest, RequestConverters::clusterGetSettings,
+            options, ClusterGetSettingsResponse::fromXContent, emptySet());
+    }
+
+    /**
+     * Asynchronously get the cluster wide settings using the Cluster Get Settings API.
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-get-settings.html"> Cluster Get Settings
+     * API on elastic.co</a>
+     * @param clusterGetSettingsRequest the request
+     * @param options the request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     * @param listener the listener to be notified upon request completion
+     */
+    public void getSettingsAsync(ClusterGetSettingsRequest clusterGetSettingsRequest, RequestOptions options,
+                                 ActionListener<ClusterGetSettingsResponse> listener) {
+        restHighLevelClient.performRequestAsyncAndParseEntity(clusterGetSettingsRequest, RequestConverters::clusterGetSettings,
+            options, ClusterGetSettingsResponse::fromXContent, listener, emptySet());
+    }
+
     /**
      * Get cluster health using the Cluster Health API.
      * See

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

@@ -36,6 +36,7 @@
 import org.elasticsearch.action.admin.cluster.repositories.get.GetRepositoriesRequest;
 import org.elasticsearch.action.admin.cluster.repositories.put.PutRepositoryRequest;
 import org.elasticsearch.action.admin.cluster.repositories.verify.VerifyRepositoryRequest;
+import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsRequest;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.elasticsearch.action.admin.cluster.snapshots.create.CreateSnapshotRequest;
 import org.elasticsearch.action.admin.cluster.storedscripts.DeleteStoredScriptRequest;
@@ -613,7 +614,7 @@ static Request searchTemplate(SearchTemplateRequest searchTemplateRequest) throw
         request.setEntity(createEntity(searchTemplateRequest, REQUEST_BODY_CONTENT_TYPE));
         return request;
     }
-    
+
     static Request multiSearchTemplate(MultiSearchTemplateRequest multiSearchTemplateRequest) throws IOException {
         Request request = new Request(HttpPost.METHOD_NAME, "/_msearch/template");
 
@@ -627,7 +628,7 @@ static Request multiSearchTemplate(MultiSearchTemplateRequest multiSearchTemplat
         byte[] source = MultiSearchTemplateRequest.writeMultiLineFormat(multiSearchTemplateRequest, xContent);
         request.setEntity(new ByteArrayEntity(source, createContentType(xContent.type())));
         return request;
-    }    
+    }
 
     static Request existsAlias(GetAliasesRequest getAliasesRequest) {
         if ((getAliasesRequest.indices() == null || getAliasesRequest.indices().length == 0) &&
@@ -719,6 +720,17 @@ static Request clusterPutSettings(ClusterUpdateSettingsRequest clusterUpdateSett
         return request;
     }
 
+    static Request clusterGetSettings(ClusterGetSettingsRequest clusterGetSettingsRequest) throws IOException {
+        Request request = new Request(HttpGet.METHOD_NAME, "/_cluster/settings");
+
+        Params parameters = new Params(request);
+        parameters.withLocal(clusterGetSettingsRequest.local());
+        parameters.withIncludeDefaults(clusterGetSettingsRequest.includeDefaults());
+        parameters.withMasterTimeout(clusterGetSettingsRequest.masterNodeTimeout());
+
+        return request;
+    }
+
     static Request getPipeline(GetPipelineRequest getPipelineRequest) {
         String endpoint = new EndpointBuilder()
             .addPathPartAsIs("_ingest/pipeline")

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

@@ -22,6 +22,8 @@
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthRequest;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
+import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsRequest;
+import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsResponse;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsResponse;
 import org.elasticsearch.cluster.health.ClusterHealthStatus;
@@ -42,6 +44,7 @@
 import static java.util.Collections.emptyMap;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
 
@@ -115,6 +118,46 @@ public void testClusterUpdateSettingNonExistent() {
                 "Elasticsearch exception [type=illegal_argument_exception, reason=transient setting [" + setting + "], not recognized]"));
     }
 
+    public void testClusterGetSettings() throws IOException {
+        final String transientSettingKey = RecoverySettings.INDICES_RECOVERY_MAX_BYTES_PER_SEC_SETTING.getKey();
+        final int transientSettingValue = 10;
+
+        final String persistentSettingKey = EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey();
+        final String persistentSettingValue = EnableAllocationDecider.Allocation.NONE.name();
+
+        Settings transientSettings =
+            Settings.builder().put(transientSettingKey, transientSettingValue, ByteSizeUnit.BYTES).build();
+        Settings persistentSettings = Settings.builder().put(persistentSettingKey, persistentSettingValue).build();
+        clusterUpdateSettings(persistentSettings, transientSettings);
+
+        ClusterGetSettingsRequest request = new ClusterGetSettingsRequest();
+        ClusterGetSettingsResponse response = execute(
+            request, highLevelClient().cluster()::getSettings, highLevelClient().cluster()::getSettingsAsync);
+        assertEquals(persistentSettings, response.getPersistentSettings());
+        assertEquals(transientSettings, response.getTransientSettings());
+        assertEquals(0, response.getDefaultSettings().size());
+    }
+
+    public void testClusterGetSettingsWithDefault() throws IOException {
+        final String transientSettingKey = RecoverySettings.INDICES_RECOVERY_MAX_BYTES_PER_SEC_SETTING.getKey();
+        final int transientSettingValue = 10;
+
+        final String persistentSettingKey = EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey();
+        final String persistentSettingValue = EnableAllocationDecider.Allocation.NONE.name();
+
+        Settings transientSettings =
+            Settings.builder().put(transientSettingKey, transientSettingValue, ByteSizeUnit.BYTES).build();
+        Settings persistentSettings = Settings.builder().put(persistentSettingKey, persistentSettingValue).build();
+        clusterUpdateSettings(persistentSettings, transientSettings);
+
+        ClusterGetSettingsRequest request = new ClusterGetSettingsRequest().includeDefaults(true);
+        ClusterGetSettingsResponse response = execute(
+            request, highLevelClient().cluster()::getSettings, highLevelClient().cluster()::getSettingsAsync);
+        assertEquals(persistentSettings, response.getPersistentSettings());
+        assertEquals(transientSettings, response.getTransientSettings());
+        assertThat(response.getDefaultSettings().size(), greaterThan(0));
+    }
+
     public void testClusterHealthGreen() throws IOException {
         ClusterHealthRequest request = new ClusterHealthRequest();
         request.timeout("5s");

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

@@ -21,9 +21,11 @@
 
 import org.apache.http.Header;
 import org.elasticsearch.action.ActionListener;
+import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.elasticsearch.action.ingest.PutPipelineRequest;
 import org.elasticsearch.action.support.PlainActionFuture;
 import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.ingest.Pipeline;
@@ -164,4 +166,12 @@ protected static void createPipeline(String pipelineId) throws IOException {
     protected static void createPipeline(PutPipelineRequest putPipelineRequest) throws IOException {
         assertOK(client().performRequest(RequestConverters.putPipeline(putPipelineRequest)));
     }
+
+    protected static void clusterUpdateSettings(Settings persistentSettings,
+                                                Settings transientSettings) throws IOException {
+        ClusterUpdateSettingsRequest request = new ClusterUpdateSettingsRequest();
+        request.persistentSettings(persistentSettings);
+        request.transientSettings(transientSettings);
+        assertOK(client().performRequest(RequestConverters.clusterPutSettings(request)));
+    }
 }

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

@@ -36,6 +36,7 @@
 import org.elasticsearch.action.admin.cluster.repositories.get.GetRepositoriesRequest;
 import org.elasticsearch.action.admin.cluster.repositories.put.PutRepositoryRequest;
 import org.elasticsearch.action.admin.cluster.repositories.verify.VerifyRepositoryRequest;
+import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsRequest;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.elasticsearch.action.admin.cluster.snapshots.create.CreateSnapshotRequest;
 import org.elasticsearch.action.admin.cluster.snapshots.delete.DeleteSnapshotRequest;
@@ -1402,42 +1403,42 @@ public void testRenderSearchTemplate() throws Exception {
         assertEquals(Collections.emptyMap(), request.getParameters());
         assertToXContentBody(searchTemplateRequest, request.getEntity());
     }
-    
+
     public void testMultiSearchTemplate() throws Exception {
         final int numSearchRequests = randomIntBetween(1, 10);
         MultiSearchTemplateRequest multiSearchTemplateRequest = new MultiSearchTemplateRequest();
-        
+
         for (int i = 0; i < numSearchRequests; i++) {
             // Create a random request.
             String[] indices = randomIndicesNames(0, 5);
             SearchRequest searchRequest = new SearchRequest(indices);
-            
+
             Map<String, String> expectedParams = new HashMap<>();
             setRandomSearchParams(searchRequest, expectedParams);
-    
+
             // scroll is not supported in the current msearch or msearchtemplate api, so unset it:
             searchRequest.scroll((Scroll) null);
             // batched reduce size is currently not set-able on a per-request basis as it is a query string parameter only
             searchRequest.setBatchedReduceSize(SearchRequest.DEFAULT_BATCHED_REDUCE_SIZE);
-            
+
             setRandomIndicesOptions(searchRequest::indicesOptions, searchRequest::indicesOptions, expectedParams);
-            
+
             SearchTemplateRequest searchTemplateRequest = new SearchTemplateRequest(searchRequest);
-    
+
             searchTemplateRequest.setScript("{\"query\": { \"match\" : { \"{{field}}\" : \"{{value}}\" }}}");
             searchTemplateRequest.setScriptType(ScriptType.INLINE);
             searchTemplateRequest.setProfile(randomBoolean());
-    
+
             Map<String, Object> scriptParams = new HashMap<>();
             scriptParams.put("field", "name");
             scriptParams.put("value", randomAlphaOfLengthBetween(2, 5));
             searchTemplateRequest.setScriptParams(scriptParams);
-    
-            multiSearchTemplateRequest.add(searchTemplateRequest);            
+
+            multiSearchTemplateRequest.add(searchTemplateRequest);
         }
 
         Request multiRequest = RequestConverters.multiSearchTemplate(multiSearchTemplateRequest);
-        
+
         assertEquals(HttpPost.METHOD_NAME, multiRequest.getMethod());
         assertEquals("/_msearch/template", multiRequest.getEndpoint());
         List<SearchTemplateRequest> searchRequests = multiSearchTemplateRequest.requests();
@@ -1446,9 +1447,9 @@ public void testMultiSearchTemplate() throws Exception {
         HttpEntity actualEntity = multiRequest.getEntity();
         byte[] expectedBytes = MultiSearchTemplateRequest.writeMultiLineFormat(multiSearchTemplateRequest, XContentType.JSON.xContent());
         assertEquals(XContentType.JSON.mediaTypeWithoutParameters(), actualEntity.getContentType().getValue());
-        assertEquals(new BytesArray(expectedBytes), new BytesArray(EntityUtils.toByteArray(actualEntity)));        
+        assertEquals(new BytesArray(expectedBytes), new BytesArray(EntityUtils.toByteArray(actualEntity)));
     }
-    
+
     public void testExistsAlias() {
         GetAliasesRequest getAliasesRequest = new GetAliasesRequest();
         String[] indices = randomBoolean() ? null : randomIndicesNames(0, 5);
@@ -1667,6 +1668,21 @@ public void testClusterPutSettings() throws IOException {
         assertEquals(expectedParams, expectedRequest.getParameters());
     }
 
+    public void testClusterGetSettings() throws IOException {
+        ClusterGetSettingsRequest request = new ClusterGetSettingsRequest();
+        Map<String, String> expectedParams = new HashMap<>();
+        setRandomMasterTimeout(request, expectedParams);
+        request.includeDefaults(randomBoolean());
+        if (request.includeDefaults()) {
+            expectedParams.put("include_defaults", String.valueOf(true));
+        }
+
+        Request expectedRequest = RequestConverters.clusterGetSettings(request);
+        assertEquals("/_cluster/settings", expectedRequest.getEndpoint());
+        assertEquals(HttpGet.METHOD_NAME, expectedRequest.getMethod());
+        assertEquals(expectedParams, expectedRequest.getParameters());
+    }
+
     public void testPutPipeline() throws IOException {
         String pipelineId = "some_pipeline_id";
         PutPipelineRequest request = new PutPipelineRequest(

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

@@ -23,6 +23,8 @@
 import org.elasticsearch.action.LatchedActionListener;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthRequest;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
+import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsRequest;
+import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsResponse;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsResponse;
 import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
@@ -49,6 +51,7 @@
 import java.util.concurrent.TimeUnit;
 
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.notNullValue;
 
 /**
@@ -189,6 +192,71 @@ public void onFailure(Exception e) {
         }
     }
 
+    public void testClusterGetSettings() throws IOException {
+        RestHighLevelClient client = highLevelClient();
+
+        // tag::get-settings-request
+        ClusterGetSettingsRequest request = new ClusterGetSettingsRequest();
+        // end::get-settings-request
+
+        // tag::get-settings-request-includeDefaults
+        request.includeDefaults(true); // <1>
+        // end::get-settings-request-includeDefaults
+
+        // tag::get-settings-request-local
+        request.local(true); // <1>
+        // end::get-settings-request-local
+
+        // tag::get-settings-request-masterTimeout
+        request.masterNodeTimeout(TimeValue.timeValueMinutes(1)); // <1>
+        request.masterNodeTimeout("1m"); // <2>
+        // end::get-settings-request-masterTimeout
+
+        // tag::get-settings-execute
+        ClusterGetSettingsResponse response = client.cluster().getSettings(request, RequestOptions.DEFAULT); // <1>
+        // end::get-settings-execute
+
+        // tag::get-settings-response
+        Settings persistentSettings = response.getPersistentSettings(); // <1>
+        Settings transientSettings = response.getTransientSettings(); // <2>
+        Settings defaultSettings = response.getDefaultSettings(); // <3>
+        String settingValue = response.getSetting("cluster.routing.allocation.enable"); // <4>
+        // end::get-settings-response
+
+        assertThat(defaultSettings.size(), greaterThan(0));
+    }
+
+    public void testClusterGetSettingsAsync() throws InterruptedException {
+        RestHighLevelClient client = highLevelClient();
+
+        ClusterGetSettingsRequest request = new ClusterGetSettingsRequest();
+
+        // tag::get-settings-execute-listener
+        ActionListener<ClusterGetSettingsResponse> listener =
+            new ActionListener<ClusterGetSettingsResponse>() {
+                @Override
+                public void onResponse(ClusterGetSettingsResponse response) {
+                    // <1>
+                }
+
+                @Override
+                public void onFailure(Exception e) {
+                    // <2>
+                }
+            };
+        // end::get-settings-execute-listener
+
+        // Replace the empty listener by a blocking listener in test
+        final CountDownLatch latch = new CountDownLatch(1);
+        listener = new LatchedActionListener<>(listener, latch);
+
+        // tag::get-settings-execute-async
+        client.cluster().getSettingsAsync(request, RequestOptions.DEFAULT, listener); // <1>
+        // end::get-settings-execute-async
+
+        assertTrue(latch.await(30L, TimeUnit.SECONDS));
+    }
+
     public void testClusterHealth() throws IOException {
         RestHighLevelClient client = highLevelClient();
         client.indices().create(new CreateIndexRequest("index"), RequestOptions.DEFAULT);