Add API for resetting state of a SystemIndexPlugin

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

@@ -9,8 +9,10 @@
 package org.elasticsearch.client;
 
 import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.client.snapshots.GetFeaturesRequest;
-import org.elasticsearch.client.snapshots.GetFeaturesResponse;
+import org.elasticsearch.client.feature.GetFeaturesRequest;
+import org.elasticsearch.client.feature.GetFeaturesResponse;
+import org.elasticsearch.client.feature.ResetFeaturesRequest;
+import org.elasticsearch.client.feature.ResetFeaturesResponse;
 
 import java.io.IOException;
 
@@ -71,4 +73,50 @@ public Cancellable getFeaturesAsync(
             emptySet()
         );
     }
+
+    /**
+     * Reset the state of Elasticsearch features, deleting system indices and performing other
+     * cleanup operations.
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/reset-features-api.html"> Rest
+     * Features API on elastic.co</a>
+     *
+     * @param resetFeaturesRequest 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 ResetFeaturesResponse resetFeatures(ResetFeaturesRequest resetFeaturesRequest, RequestOptions options)
+        throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(
+            resetFeaturesRequest,
+            FeaturesRequestConverters::resetFeatures,
+            options,
+            ResetFeaturesResponse::parse,
+            emptySet()
+        );
+    }
+
+    /**
+     * Asynchronously reset the state of Elasticsearch features, deleting system indices and performing other
+     * cleanup operations.
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/get-features-api.html"> Get Snapshottable
+     * Features API on elastic.co</a>
+     *
+     * @param resetFeaturesRequest 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
+     * @return cancellable that may be used to cancel the request
+     */
+    public Cancellable resetFeaturesAsync(
+        ResetFeaturesRequest resetFeaturesRequest, RequestOptions options,
+        ActionListener<ResetFeaturesResponse> listener) {
+        return restHighLevelClient.performRequestAsyncAndParseEntity(
+            resetFeaturesRequest,
+            FeaturesRequestConverters::resetFeatures,
+            options,
+            ResetFeaturesResponse::parse,
+            listener,
+            emptySet()
+        );
+    }
 }

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

@@ -9,7 +9,9 @@
 package org.elasticsearch.client;
 
 import org.apache.http.client.methods.HttpGet;
-import org.elasticsearch.client.snapshots.GetFeaturesRequest;
+import org.apache.http.client.methods.HttpPost;
+import org.elasticsearch.client.feature.GetFeaturesRequest;
+import org.elasticsearch.client.feature.ResetFeaturesRequest;
 
 public class FeaturesRequestConverters {
 
@@ -23,4 +25,9 @@ static Request getFeatures(GetFeaturesRequest getFeaturesRequest) {
         request.addParameters(parameters.asMap());
         return request;
     }
+
+    static Request resetFeatures(ResetFeaturesRequest resetFeaturesRequest) {
+        String endpoint = "/_features/_reset";
+        return new Request(HttpPost.METHOD_NAME, endpoint);
+    }
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/snapshots/GetFeaturesRequest.java → client/rest-high-level/src/main/java/org/elasticsearch/client/feature/GetFeaturesRequest.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.client.snapshots;
+package org.elasticsearch.client.feature;
 
 import org.elasticsearch.client.TimedRequest;
 

client/rest-high-level/src/main/java/org/elasticsearch/client/snapshots/GetFeaturesResponse.java → client/rest-high-level/src/main/java/org/elasticsearch/client/feature/GetFeaturesResponse.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.client.snapshots;
+package org.elasticsearch.client.feature;
 
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.xcontent.ConstructingObjectParser;

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

@@ -0,0 +1,14 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.client.feature;
+
+import org.elasticsearch.client.TimedRequest;
+
+public class ResetFeaturesRequest extends TimedRequest {
+}

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

@@ -0,0 +1,82 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.client.feature;
+
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.ObjectParser;
+import org.elasticsearch.common.xcontent.XContentParser;
+
+import java.util.List;
+
+public class ResetFeaturesResponse {
+    private final List<ResetFeatureStateStatus> features;
+
+    private static final ParseField FEATURES = new ParseField("features");
+
+    @SuppressWarnings("unchecked")
+    private static final ConstructingObjectParser<ResetFeaturesResponse, Void> PARSER = new ConstructingObjectParser<>(
+        "snapshottable_features_response", true,
+        (a, ctx) -> new ResetFeaturesResponse((List<ResetFeatureStateStatus>) a[0])
+    );
+
+    static {
+        PARSER.declareObjectArray(
+            ConstructingObjectParser.constructorArg(),
+            ResetFeaturesResponse.ResetFeatureStateStatus::parse, FEATURES);
+    }
+
+    public ResetFeaturesResponse(List<ResetFeatureStateStatus> features) {
+        this.features = features;
+    }
+
+    public List<ResetFeatureStateStatus> getFeatures() {
+        return features;
+    }
+
+    public static ResetFeaturesResponse parse(XContentParser parser) {
+        return PARSER.apply(parser, null);
+    }
+
+    public static class ResetFeatureStateStatus {
+        private final String featureName;
+        private final String status;
+
+        private static final ParseField FEATURE_NAME = new ParseField("feature_name");
+        private static final ParseField STATUS = new ParseField("status");
+
+        private static final ConstructingObjectParser<ResetFeatureStateStatus, Void> PARSER =  new ConstructingObjectParser<>(
+            "features", true, (a, ctx) -> new ResetFeatureStateStatus((String) a[0], (String) a[1])
+        );
+
+        static {
+            PARSER.declareField(ConstructingObjectParser.constructorArg(),
+                (p, c) -> p.text(), FEATURE_NAME, ObjectParser.ValueType.STRING);
+            PARSER.declareField(ConstructingObjectParser.constructorArg(),
+                (p, c) -> p.text(), STATUS, ObjectParser.ValueType.STRING);
+        }
+
+        ResetFeatureStateStatus(String featureName, String status) {
+            this.featureName = featureName;
+            this.status = status;
+        }
+
+        public static ResetFeatureStateStatus parse(XContentParser parser, Void ctx) {
+            return PARSER.apply(parser, ctx);
+        }
+
+        public String getFeatureName() {
+            return featureName;
+        }
+
+        public String getStatus() {
+            return status;
+        }
+    }
+}

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

@@ -8,8 +8,10 @@
 
 package org.elasticsearch.client;
 
-import org.elasticsearch.client.snapshots.GetFeaturesRequest;
-import org.elasticsearch.client.snapshots.GetFeaturesResponse;
+import org.elasticsearch.client.feature.GetFeaturesRequest;
+import org.elasticsearch.client.feature.GetFeaturesResponse;
+import org.elasticsearch.client.feature.ResetFeaturesRequest;
+import org.elasticsearch.client.feature.ResetFeaturesResponse;
 
 import java.io.IOException;
 
@@ -28,4 +30,17 @@ public void testGetFeatures() throws IOException {
         assertThat(response.getFeatures().size(), greaterThan(1));
         assertTrue(response.getFeatures().stream().anyMatch(feature -> "tasks".equals(feature.getFeatureName())));
     }
+
+    public void testResetFeatures() throws IOException {
+        ResetFeaturesRequest request = new ResetFeaturesRequest();
+
+        ResetFeaturesResponse response = execute(request,
+            highLevelClient().features()::resetFeatures, highLevelClient().features()::resetFeaturesAsync);
+
+        assertThat(response, notNullValue());
+        assertThat(response.getFeatures(), notNullValue());
+        assertThat(response.getFeatures().size(), greaterThan(1));
+        assertTrue(response.getFeatures().stream().anyMatch(
+            feature -> "tasks".equals(feature.getFeatureName()) && "SUCCESS".equals(feature.getStatus())));
+    }
 }

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

@@ -9,6 +9,7 @@
 package org.elasticsearch.client.snapshots;
 
 import org.elasticsearch.client.AbstractResponseTestCase;
+import org.elasticsearch.client.feature.GetFeaturesResponse;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentType;
 

rest-api-spec/src/main/resources/rest-api-spec/api/features.reset_features.json

@@ -0,0 +1,23 @@
+{
+  "features.reset_features":{
+    "documentation":{
+      "url":"https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-snapshots.html",
+      "description":"Resets the internal state of features, usually by deleting system indices"
+    },
+    "stability":"experimental",
+    "visibility":"public",
+    "headers":{
+      "accept": [ "application/json"]
+    },
+    "url":{
+      "paths":[
+        {
+          "path":"/_features/_reset",
+          "methods":[
+            "POST"
+          ]
+        }
+      ]
+    }
+  }
+}

rest-api-spec/src/main/resources/rest-api-spec/test/features.reset_features/10_basic.yml

@@ -0,0 +1,8 @@
+---
+"Get Features":
+  - skip:
+      features: contains
+      version: " - 7.99.99" # Adjust this after backport
+      reason: "This API was added in 7.13.0"
+  - do: { features.get_features: {}}
+  - contains: {'features': {'name': 'tasks'}}