HLRC: migration get assistance API (#32744)

The request and response classes have been extracted from `IndexUpgradeInfoAction` into top-level classes, and moved to the protocol jar. The `UpgradeActionRequired` enum is also moved.

Relates to #29827

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

@@ -48,7 +48,7 @@ import static java.util.Collections.emptySet;
  * See the <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/licensing-apis.html">
  * X-Pack Licensing APIs on elastic.co</a> for more information.
  */
-public class LicenseClient {
+public final class LicenseClient {
 
     private final RestHighLevelClient restHighLevelClient;
 
@@ -98,9 +98,8 @@ public class LicenseClient {
             response -> new GetLicenseResponse(convertResponseToJson(response)), listener, emptySet());
     }
 
-
     /**
-     * Converts an entire response into a json sting
+     * Converts an entire response into a json string
      *
      * This is useful for responses that we don't parse on the client side, but instead work as string
      * such as in case of the license JSON

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

@@ -0,0 +1,55 @@
+/*
+ * 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.client;
+
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoRequest;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoResponse;
+
+import java.io.IOException;
+import java.util.Collections;
+
+/**
+ * A wrapper for the {@link RestHighLevelClient} that provides methods for
+ * accessing the Elastic License-related methods
+ * <p>
+ * See the <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/migration-api.html">
+ * X-Pack Migration APIs on elastic.co</a> for more information.
+ */
+public final class MigrationClient {
+
+    private final RestHighLevelClient restHighLevelClient;
+
+    MigrationClient(RestHighLevelClient restHighLevelClient) {
+        this.restHighLevelClient = restHighLevelClient;
+    }
+
+    /**
+     * Get Migration Assistance for one or more indices
+     *
+     * @param request 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 IndexUpgradeInfoResponse getAssistance(IndexUpgradeInfoRequest request, RequestOptions options) throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(request, RequestConverters::getMigrationAssistance, options,
+            IndexUpgradeInfoResponse::fromXContent, Collections.emptySet());
+    }
+}

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

@@ -110,6 +110,7 @@ import org.elasticsearch.protocol.xpack.XPackInfoRequest;
 import org.elasticsearch.protocol.xpack.XPackUsageRequest;
 import org.elasticsearch.protocol.xpack.license.GetLicenseRequest;
 import org.elasticsearch.protocol.xpack.license.PutLicenseRequest;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoRequest;
 import org.elasticsearch.protocol.xpack.ml.PutJobRequest;
 import org.elasticsearch.protocol.xpack.watcher.DeleteWatchRequest;
 import org.elasticsearch.protocol.xpack.watcher.PutWatchRequest;
@@ -1196,12 +1197,22 @@ final class RequestConverters {
             .addPathPartAsIs("anomaly_detectors")
             .addPathPart(putJobRequest.getJob().getId())
             .build();
-
         Request request = new Request(HttpPut.METHOD_NAME, endpoint);
         request.setEntity(createEntity(putJobRequest, REQUEST_BODY_CONTENT_TYPE));
         return request;
     }
 
+    static Request getMigrationAssistance(IndexUpgradeInfoRequest indexUpgradeInfoRequest) {
+        EndpointBuilder endpointBuilder = new EndpointBuilder()
+            .addPathPartAsIs("_xpack/migration/assistance")
+            .addCommaSeparatedPathParts(indexUpgradeInfoRequest.indices());
+        String endpoint = endpointBuilder.build();
+        Request request = new Request(HttpGet.METHOD_NAME, endpoint);
+        Params parameters = new Params(request);
+        parameters.withIndicesOptions(indexUpgradeInfoRequest.indicesOptions());
+        return request;
+    }
+
     private static HttpEntity createEntity(ToXContent toXContent, XContentType xContentType) throws IOException {
         BytesRef source = XContentHelper.toXContent(toXContent, xContentType, false).toBytesRef();
         return new ByteArrayEntity(source.bytes, source.offset, source.length, createContentType(xContentType));

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

@@ -210,6 +210,7 @@ public class RestHighLevelClient implements Closeable {
     private final XPackClient xPackClient = new XPackClient(this);
     private final WatcherClient watcherClient = new WatcherClient(this);
     private final LicenseClient licenseClient = new LicenseClient(this);
+    private final MigrationClient migrationClient = new MigrationClient(this);
     private final MachineLearningClient machineLearningClient = new MachineLearningClient(this);
 
     /**
@@ -334,6 +335,18 @@ public class RestHighLevelClient implements Closeable {
      */
     public LicenseClient license() { return licenseClient; }
 
+    /**
+     * Provides methods for accessing the Elastic Licensed Licensing APIs that
+     * are shipped with the default distribution of Elasticsearch. All of
+     * these APIs will 404 if run against the OSS distribution of Elasticsearch.
+     * <p>
+     * See the <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/migration-api.html">
+     * Migration APIs on elastic.co</a> for more information.
+     */
+    public MigrationClient migration() {
+        return migrationClient;
+    }
+
     /**
      * Provides methods for accessing the Elastic Licensed Machine Learning APIs that
      * are shipped with the Elastic Stack distribution of Elasticsearch. All of

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

@@ -0,0 +1,43 @@
+/*
+ * 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.client;
+
+import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoRequest;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoResponse;
+
+import java.io.IOException;
+
+public class MigrationIT extends ESRestHighLevelClientTestCase {
+
+    public void testGetAssistance() throws IOException {
+        RestHighLevelClient client = highLevelClient();
+        {
+            IndexUpgradeInfoResponse response = client.migration().getAssistance(new IndexUpgradeInfoRequest(), RequestOptions.DEFAULT);
+            assertEquals(0, response.getActions().size());
+        }
+        {
+            client.indices().create(new CreateIndexRequest("test"), RequestOptions.DEFAULT);
+            IndexUpgradeInfoResponse response = client.migration().getAssistance(
+                new IndexUpgradeInfoRequest("test"), RequestOptions.DEFAULT);
+            assertEquals(0, response.getActions().size());
+        }
+    }
+}

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

@@ -126,6 +126,7 @@ import org.elasticsearch.index.rankeval.RankEvalSpec;
 import org.elasticsearch.index.rankeval.RatedRequest;
 import org.elasticsearch.index.rankeval.RestRankEvalAction;
 import org.elasticsearch.protocol.xpack.XPackInfoRequest;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoRequest;
 import org.elasticsearch.protocol.xpack.watcher.DeleteWatchRequest;
 import org.elasticsearch.protocol.xpack.watcher.PutWatchRequest;
 import org.elasticsearch.repositories.fs.FsRepository;
@@ -2552,6 +2553,23 @@ public class RequestConvertersTests extends ESTestCase {
         assertEquals(expectedParams, request.getParameters());
     }
 
+    public void testGetMigrationAssistance() {
+        IndexUpgradeInfoRequest upgradeInfoRequest = new IndexUpgradeInfoRequest();
+        String expectedEndpoint = "/_xpack/migration/assistance";
+        if (randomBoolean()) {
+            String[] indices = randomIndicesNames(1, 5);
+            upgradeInfoRequest.indices(indices);
+            expectedEndpoint += "/" + String.join(",", indices);
+        }
+        Map<String, String> expectedParams = new HashMap<>();
+        setRandomIndicesOptions(upgradeInfoRequest::indicesOptions, upgradeInfoRequest::indicesOptions, expectedParams);
+        Request request = RequestConverters.getMigrationAssistance(upgradeInfoRequest);
+        assertEquals(HttpGet.METHOD_NAME, request.getMethod());
+        assertEquals(expectedEndpoint, request.getEndpoint());
+        assertNull(request.getEntity());
+        assertEquals(expectedParams, request.getParameters());
+    }
+
     public void testXPackPutWatch() throws Exception {
         PutWatchRequest putWatchRequest = new PutWatchRequest();
         String watchId = randomAlphaOfLength(10);

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

@@ -757,7 +757,8 @@ public class RestHighLevelClientTests extends ESTestCase {
                         if (apiName.startsWith("xpack.") == false &&
                             apiName.startsWith("license.") == false &&
                             apiName.startsWith("machine_learning.") == false &&
-                            apiName.startsWith("watcher.") == false) {
+                            apiName.startsWith("watcher.") == false &&
+                            apiName.startsWith("migration.") == false) {
                             apiNotFound.add(apiName);
                         }
                     }

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

@@ -0,0 +1,83 @@
+/*
+ * 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.client.documentation;
+
+import org.elasticsearch.action.support.IndicesOptions;
+import org.elasticsearch.client.ESRestHighLevelClientTestCase;
+import org.elasticsearch.client.RequestOptions;
+import org.elasticsearch.client.RestHighLevelClient;
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoRequest;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoResponse;
+import org.elasticsearch.protocol.xpack.migration.UpgradeActionRequired;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * This class is used to generate the Java Migration API documentation.
+ * You need to wrap your code between two tags like:
+ * // tag::example
+ * // end::example
+ *
+ * Where example is your tag name.
+ *
+ * Then in the documentation, you can extract what is between tag and end tags with
+ * ["source","java",subs="attributes,callouts,macros"]
+ * --------------------------------------------------
+ * include-tagged::{doc-tests}/MigrationClientDocumentationIT.java[example]
+ * --------------------------------------------------
+ *
+ * The column width of the code block is 84. If the code contains a line longer
+ * than 84, the line will be cut and a horizontal scroll bar will be displayed.
+ * (the code indentation of the tag is not included in the width)
+ */
+public class MigrationClientDocumentationIT extends ESRestHighLevelClientTestCase {
+
+    public void testGetAssistance() throws IOException {
+        RestHighLevelClient client = highLevelClient();
+
+        // tag::get-assistance-request
+        IndexUpgradeInfoRequest request = new IndexUpgradeInfoRequest(); // <1>
+        // end::get-assistance-request
+
+        // tag::get-assistance-request-indices
+        request.indices("index1", "index2"); // <1>
+        // end::get-assistance-request-indices
+
+        request.indices(Strings.EMPTY_ARRAY);
+
+        // tag::get-assistance-request-indices-options
+        request.indicesOptions(IndicesOptions.lenientExpandOpen()); // <1>
+        // end::get-assistance-request-indices-options
+
+        // tag::get-assistance-execute
+        IndexUpgradeInfoResponse response = client.migration().getAssistance(request, RequestOptions.DEFAULT);
+        // end::get-assistance-execute
+
+        // tag::get-assistance-response
+        Map<String, UpgradeActionRequired> actions = response.getActions();
+        for (Map.Entry<String, UpgradeActionRequired> entry : actions.entrySet()) {
+            String index = entry.getKey(); // <1>
+            UpgradeActionRequired actionRequired = entry.getValue(); // <2>
+        }
+        // end::get-assistance-response
+    }
+}

docs/java-rest/high-level/migration/get-assistance.asciidoc

@@ -0,0 +1,49 @@
+[[java-rest-high-migration-get-assistance]]
+=== Migration Get Assistance
+
+[[java-rest-high-migraton-get-assistance-request]]
+==== Index Upgrade Info Request
+
+An `IndexUpgradeInfoRequest` does not require any argument:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MigrationClientDocumentationIT.java[get-assistance-request]
+--------------------------------------------------
+<1> Create a new request instance
+
+==== Optional arguments
+The following arguments can optionally be provided:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MigrationClientDocumentationIT.java[get-assistance-request-indices]
+--------------------------------------------------
+<1> Set the indices to the request
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MigrationClientDocumentationIT.java[get-assistance-request-indices-options]
+--------------------------------------------------
+<1> Set the `IndicesOptions` to control how unavailable indices are resolved and
+how wildcard expressions are expanded
+
+[[java-rest-high-migration-get-assistance-execution]]
+==== Execution
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MigrationClientDocumentationIT.java[get-assistance-execute]
+--------------------------------------------------
+
+[[java-rest-high-migration-get-assistance-response]]
+==== Response
+
+The returned `IndexUpgradeInfoResponse` contains the actions required for each index.
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MigrationClientDocumentationIT.java[get-assistance-response]
+--------------------------------------------------
+<1> Retrieve the index
+<2> Retrieve the action required for the migration of the current index

docs/java-rest/high-level/supported-apis.asciidoc

@@ -198,6 +198,14 @@ The Java High Level REST Client supports the following Licensing APIs:
 include::licensing/put-license.asciidoc[]
 include::licensing/get-license.asciidoc[]
 
+== Migration APIs
+
+The Java High Level REST Client supports the following Migration APIs:
+
+* <<java-rest-high-migration-get-assistance>>
+
+include::migration/get-assistance.asciidoc[]
+
 == Watcher APIs
 
 The Java High Level REST Client supports the following Watcher APIs:

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/upgrade/actions/IndexUpgradeInfoAction.java

@@ -6,27 +6,13 @@
 package org.elasticsearch.xpack.core.upgrade.actions;
 
 import org.elasticsearch.action.Action;
-import org.elasticsearch.action.ActionRequestValidationException;
-import org.elasticsearch.action.ActionResponse;
-import org.elasticsearch.action.IndicesRequest;
 import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.action.support.master.MasterNodeReadOperationRequestBuilder;
-import org.elasticsearch.action.support.master.MasterNodeReadRequest;
 import org.elasticsearch.client.ElasticsearchClient;
-import org.elasticsearch.common.io.stream.StreamInput;
-import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.common.xcontent.ToXContentObject;
-import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.xpack.core.upgrade.UpgradeActionRequired;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoRequest;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoResponse;
 
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.Map;
-import java.util.Objects;
-
-import static org.elasticsearch.action.ValidateActions.addValidationError;
-
-public class IndexUpgradeInfoAction extends Action<IndexUpgradeInfoAction.Response> {
+public class IndexUpgradeInfoAction extends Action<IndexUpgradeInfoResponse> {
 
     public static final IndexUpgradeInfoAction INSTANCE = new IndexUpgradeInfoAction();
     public static final String NAME = "cluster:admin/xpack/upgrade/info";
@@ -36,149 +22,15 @@ public class IndexUpgradeInfoAction extends Action<IndexUpgradeInfoAction.Respon
     }
 
     @Override
-    public Response newResponse() {
-        return new Response();
-    }
-
-    public static class Response extends ActionResponse implements ToXContentObject {
-        private Map<String, UpgradeActionRequired> actions;
-
-        public Response() {
-
-        }
-
-        public Response(Map<String, UpgradeActionRequired> actions) {
-            this.actions = actions;
-        }
-
-        @Override
-        public void readFrom(StreamInput in) throws IOException {
-            super.readFrom(in);
-            actions = in.readMap(StreamInput::readString, UpgradeActionRequired::readFromStream);
-        }
-
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            super.writeTo(out);
-            out.writeMap(actions, StreamOutput::writeString, (out1, value) -> value.writeTo(out1));
-        }
-
-        public Map<String, UpgradeActionRequired> getActions() {
-            return actions;
-        }
-
-        @Override
-        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject();
-            {
-                builder.startObject("indices");
-                for (Map.Entry<String, UpgradeActionRequired> entry : actions.entrySet()) {
-                    builder.startObject(entry.getKey());
-                    {
-                        builder.field("action_required", entry.getValue().toString());
-                    }
-                    builder.endObject();
-                }
-                builder.endObject();
-            }
-            builder.endObject();
-            return builder;
-        }
-
-        @Override
-        public boolean equals(Object o) {
-            if (this == o) return true;
-            if (o == null || getClass() != o.getClass()) return false;
-            Response response = (Response) o;
-            return Objects.equals(actions, response.actions);
-        }
-
-        @Override
-        public int hashCode() {
-            return Objects.hash(actions);
-        }
+    public IndexUpgradeInfoResponse newResponse() {
+        return new IndexUpgradeInfoResponse();
     }
 
-    public static class Request extends MasterNodeReadRequest<Request> implements IndicesRequest.Replaceable {
-
-        private String[] indices = null;
-        private IndicesOptions indicesOptions = IndicesOptions.fromOptions(false, true, true, true);
-
-        // for serialization
-        public Request() {
-
-        }
-
-        public Request(String... indices) {
-            this.indices = indices;
-        }
-
-        public Request(StreamInput in) throws IOException {
-            super(in);
-            indices = in.readStringArray();
-            indicesOptions = IndicesOptions.readIndicesOptions(in);
-        }
-
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            super.writeTo(out);
-            out.writeStringArray(indices);
-            indicesOptions.writeIndicesOptions(out);
-        }
-
-        @Override
-        public String[] indices() {
-            return indices;
-        }
-
-        @Override
-        public Request indices(String... indices) {
-            this.indices = indices;
-            return this;
-        }
-
-        @Override
-        public IndicesOptions indicesOptions() {
-            return indicesOptions;
-        }
-
-        public void indicesOptions(IndicesOptions indicesOptions) {
-            this.indicesOptions = indicesOptions;
-        }
-
-        @Override
-        public ActionRequestValidationException validate() {
-            ActionRequestValidationException validationException = null;
-            if (indices == null) {
-                validationException = addValidationError("index/indices is missing", validationException);
-            }
-            return validationException;
-        }
-
-        @Override
-        public void readFrom(StreamInput in) throws IOException {
-            throw new UnsupportedOperationException("usage of Streamable is to be replaced by Writeable");
-        }
-
-        @Override
-        public boolean equals(Object o) {
-            if (this == o) return true;
-            if (o == null || getClass() != o.getClass()) return false;
-            Request request = (Request) o;
-            return Arrays.equals(indices, request.indices) &&
-                    Objects.equals(indicesOptions.toString(), request.indicesOptions.toString());
-        }
-
-        @Override
-        public int hashCode() {
-            return Objects.hash(Arrays.hashCode(indices), indicesOptions.toString());
-        }
-    }
-
-    public static class RequestBuilder extends MasterNodeReadOperationRequestBuilder<Request, Response, RequestBuilder> {
+    public static class RequestBuilder
+        extends MasterNodeReadOperationRequestBuilder<IndexUpgradeInfoRequest, IndexUpgradeInfoResponse, RequestBuilder> {
 
         public RequestBuilder(ElasticsearchClient client) {
-            super(client, INSTANCE, new Request());
+            super(client, INSTANCE, new IndexUpgradeInfoRequest());
         }
 
         public RequestBuilder setIndices(String... indices) {
@@ -191,5 +43,4 @@ public class IndexUpgradeInfoAction extends Action<IndexUpgradeInfoAction.Respon
             return this;
         }
     }
-
-}
+}

x-pack/plugin/upgrade/src/main/java/org/elasticsearch/xpack/upgrade/IndexUpgradeCheck.java

@@ -13,11 +13,11 @@ import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.reindex.BulkByScrollResponse;
+import org.elasticsearch.protocol.xpack.migration.UpgradeActionRequired;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.tasks.TaskId;
 import org.elasticsearch.transport.TransportResponse;
 import org.elasticsearch.xpack.core.upgrade.IndexUpgradeCheckVersion;
-import org.elasticsearch.xpack.core.upgrade.UpgradeActionRequired;
 
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;

x-pack/plugin/upgrade/src/main/java/org/elasticsearch/xpack/upgrade/IndexUpgradeService.java

@@ -16,8 +16,8 @@ import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.IndexNotFoundException;
 import org.elasticsearch.index.reindex.BulkByScrollResponse;
+import org.elasticsearch.protocol.xpack.migration.UpgradeActionRequired;
 import org.elasticsearch.tasks.TaskId;
-import org.elasticsearch.xpack.core.upgrade.UpgradeActionRequired;
 
 import java.util.HashMap;
 import java.util.List;

x-pack/plugin/upgrade/src/main/java/org/elasticsearch/xpack/upgrade/actions/TransportIndexUpgradeInfoAction.java

@@ -17,17 +17,19 @@ import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.license.LicenseUtils;
 import org.elasticsearch.license.XPackLicenseState;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoRequest;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoResponse;
+import org.elasticsearch.protocol.xpack.migration.UpgradeActionRequired;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 import org.elasticsearch.xpack.core.XPackField;
 import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeInfoAction;
 import org.elasticsearch.xpack.upgrade.IndexUpgradeService;
-import org.elasticsearch.xpack.core.upgrade.UpgradeActionRequired;
 
 import java.util.Map;
 
-public class TransportIndexUpgradeInfoAction extends TransportMasterNodeReadAction<IndexUpgradeInfoAction.Request,
-        IndexUpgradeInfoAction.Response> {
+public class TransportIndexUpgradeInfoAction
+    extends TransportMasterNodeReadAction<IndexUpgradeInfoRequest, IndexUpgradeInfoResponse> {
 
     private final IndexUpgradeService indexUpgradeService;
     private final XPackLicenseState licenseState;
@@ -40,7 +42,7 @@ public class TransportIndexUpgradeInfoAction extends TransportMasterNodeReadActi
                                            IndexNameExpressionResolver indexNameExpressionResolver,
                                            XPackLicenseState licenseState) {
         super(settings, IndexUpgradeInfoAction.NAME, transportService, clusterService, threadPool, actionFilters,
-            IndexUpgradeInfoAction.Request::new, indexNameExpressionResolver);
+            IndexUpgradeInfoRequest::new, indexNameExpressionResolver);
         this.indexUpgradeService = indexUpgradeService;
         this.licenseState = licenseState;
     }
@@ -51,23 +53,23 @@ public class TransportIndexUpgradeInfoAction extends TransportMasterNodeReadActi
     }
 
     @Override
-    protected IndexUpgradeInfoAction.Response newResponse() {
-        return new IndexUpgradeInfoAction.Response();
+    protected IndexUpgradeInfoResponse newResponse() {
+        return new IndexUpgradeInfoResponse();
     }
 
     @Override
-    protected ClusterBlockException checkBlock(IndexUpgradeInfoAction.Request request, ClusterState state) {
+    protected ClusterBlockException checkBlock(IndexUpgradeInfoRequest request, ClusterState state) {
         // Cluster is not affected but we look up repositories in metadata
         return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_READ);
     }
 
     @Override
-    protected final void masterOperation(final IndexUpgradeInfoAction.Request request, ClusterState state,
-                                         final ActionListener<IndexUpgradeInfoAction.Response> listener) {
+    protected final void masterOperation(final IndexUpgradeInfoRequest request, ClusterState state,
+                                         final ActionListener<IndexUpgradeInfoResponse> listener) {
         if (licenseState.isUpgradeAllowed()) {
             Map<String, UpgradeActionRequired> results =
                     indexUpgradeService.upgradeInfo(request.indices(), request.indicesOptions(), state);
-            listener.onResponse(new IndexUpgradeInfoAction.Response(results));
+            listener.onResponse(new IndexUpgradeInfoResponse(results));
         } else {
             listener.onFailure(LicenseUtils.newComplianceException(XPackField.UPGRADE));
         }

x-pack/plugin/upgrade/src/main/java/org/elasticsearch/xpack/upgrade/rest/RestIndexUpgradeInfoAction.java

@@ -9,12 +9,12 @@ import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.client.node.NodeClient;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoRequest;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.action.RestToXContentListener;
 import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeInfoAction;
-import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeInfoAction.Request;
 
 import java.io.IOException;
 
@@ -41,7 +41,7 @@ public class RestIndexUpgradeInfoAction extends BaseRestHandler {
     }
 
     private RestChannelConsumer handleGet(final RestRequest request, NodeClient client) {
-        Request infoRequest = new Request(Strings.splitStringByCommaToArray(request.param("index")));
+        IndexUpgradeInfoRequest infoRequest = new IndexUpgradeInfoRequest(Strings.splitStringByCommaToArray(request.param("index")));
         infoRequest.indicesOptions(IndicesOptions.fromRequest(request, infoRequest.indicesOptions()));
         return channel -> client.execute(IndexUpgradeInfoAction.INSTANCE, infoRequest, new RestToXContentListener<>(channel));
     }

x-pack/plugin/upgrade/src/test/java/org/elasticsearch/xpack/upgrade/IndexUpgradeIT.java

@@ -14,12 +14,12 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.index.IndexNotFoundException;
 import org.elasticsearch.index.reindex.BulkByScrollResponse;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoResponse;
+import org.elasticsearch.protocol.xpack.migration.UpgradeActionRequired;
 import org.elasticsearch.tasks.TaskId;
 import org.elasticsearch.transport.TransportResponse;
-import org.elasticsearch.xpack.core.upgrade.UpgradeActionRequired;
 import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeAction;
 import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeInfoAction;
-import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeInfoAction.Response;
 import org.junit.Before;
 
 import java.util.Collections;
@@ -41,7 +41,7 @@ public class IndexUpgradeIT extends IndexUpgradeIntegTestCase {
         // Testing only negative case here, the positive test is done in bwcTests
         assertAcked(client().admin().indices().prepareCreate("test").get());
         ensureYellow("test");
-        Response response = new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("test").get();
+        IndexUpgradeInfoResponse response = new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("test").get();
         assertThat(response.getActions().entrySet(), empty());
     }
 
@@ -57,7 +57,7 @@ public class IndexUpgradeIT extends IndexUpgradeIntegTestCase {
                 () -> new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("test").get());
         assertThat(e.getMessage(), equalTo("current license is non-compliant for [upgrade]"));
         enableLicensing();
-        Response response = new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("test").get();
+        IndexUpgradeInfoResponse response = new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("test").get();
         assertThat(response.getActions().entrySet(), empty());
     }
 
@@ -132,7 +132,7 @@ public class IndexUpgradeIT extends IndexUpgradeIntegTestCase {
 
     public void testIndexUpgradeInfoOnEmptyCluster() {
         // On empty cluster asking for all indices shouldn't fail since no indices means nothing needs to be upgraded
-        Response response = new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("_all").get();
+        IndexUpgradeInfoResponse response = new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("_all").get();
         assertThat(response.getActions().entrySet(), empty());
 
         // but calling on a particular index should fail

x-pack/plugin/upgrade/src/test/java/org/elasticsearch/xpack/upgrade/IndexUpgradeServiceTests.java

@@ -15,8 +15,8 @@ import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.metadata.MetaData;
 import org.elasticsearch.common.UUIDs;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.protocol.xpack.migration.UpgradeActionRequired;
 import org.elasticsearch.test.ESTestCase;
-import org.elasticsearch.xpack.core.upgrade.UpgradeActionRequired;
 
 import java.io.IOException;
 import java.util.Arrays;

x-pack/plugin/upgrade/src/test/java/org/elasticsearch/xpack/upgrade/IndexUpgradeTasksIT.java

@@ -30,6 +30,8 @@ import org.elasticsearch.plugins.ActionPlugin;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.plugins.PluginsService;
 import org.elasticsearch.plugins.ScriptPlugin;
+import org.elasticsearch.protocol.xpack.migration.IndexUpgradeInfoResponse;
+import org.elasticsearch.protocol.xpack.migration.UpgradeActionRequired;
 import org.elasticsearch.script.MockScriptEngine;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.script.ScriptContext;
@@ -39,7 +41,6 @@ import org.elasticsearch.script.ScriptType;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.watcher.ResourceWatcherService;
-import org.elasticsearch.xpack.core.upgrade.UpgradeActionRequired;
 import org.elasticsearch.xpack.core.upgrade.UpgradeField;
 import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeAction;
 import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeInfoAction;
@@ -171,7 +172,7 @@ public class IndexUpgradeTasksIT extends ESIntegTestCase {
         ensureYellow("test");
 
 
-        IndexUpgradeInfoAction.Response infoResponse = new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("test").get();
+        IndexUpgradeInfoResponse infoResponse = new IndexUpgradeInfoAction.RequestBuilder(client()).setIndices("test").get();
         assertThat(infoResponse.getActions().keySet(), contains("test"));
         assertThat(infoResponse.getActions().get("test"), equalTo(UpgradeActionRequired.UPGRADE));
 

x-pack/plugin/upgrade/src/test/java/org/elasticsearch/xpack/upgrade/actions/IndexUpgradeInfoActionRequestTests.java

@@ -1,32 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License;
- * you may not use this file except in compliance with the Elastic License.
- */
-package org.elasticsearch.xpack.upgrade.actions;
-
-import org.elasticsearch.action.support.IndicesOptions;
-import org.elasticsearch.common.io.stream.Writeable;
-import org.elasticsearch.test.AbstractWireSerializingTestCase;
-import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeInfoAction.Request;
-
-public class IndexUpgradeInfoActionRequestTests extends AbstractWireSerializingTestCase<Request> {
-    @Override
-    protected Request createTestInstance() {
-        int indexCount = randomInt(4);
-        String[] indices = new String[indexCount];
-        for (int i = 0; i < indexCount; i++) {
-            indices[i] = randomAlphaOfLength(10);
-        }
-        Request request = new Request(indices);
-        if (randomBoolean()) {
-            request.indicesOptions(IndicesOptions.fromOptions(randomBoolean(), randomBoolean(), randomBoolean(), randomBoolean()));
-        }
-        return request;
-    }
-
-    @Override
-    protected Writeable.Reader<Request> instanceReader() {
-        return Request::new;
-    }
-}

x-pack/plugin/upgrade/src/test/java/org/elasticsearch/xpack/upgrade/actions/IndexUpgradeInfoActionResponseTests.java

@@ -1,33 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License;
- * you may not use this file except in compliance with the Elastic License.
- */
-package org.elasticsearch.xpack.upgrade.actions;
-
-import org.elasticsearch.test.AbstractStreamableTestCase;
-import org.elasticsearch.xpack.core.upgrade.UpgradeActionRequired;
-import org.elasticsearch.xpack.core.upgrade.actions.IndexUpgradeInfoAction.Response;
-
-import java.util.EnumSet;
-import java.util.HashMap;
-import java.util.Map;
-
-public class IndexUpgradeInfoActionResponseTests extends AbstractStreamableTestCase<Response> {
-
-
-    @Override
-    protected Response createTestInstance() {
-        int actionsCount = randomIntBetween(0, 5);
-        Map<String, UpgradeActionRequired> actions = new HashMap<>(actionsCount);
-        for (int i = 0; i < actionsCount; i++) {
-            actions.put(randomAlphaOfLength(10), randomFrom(EnumSet.allOf(UpgradeActionRequired.class)));
-        }
-        return new Response(actions);
-    }
-
-    @Override
-    protected Response createBlankInstance() {
-        return new Response();
-    }
-}

x-pack/protocol/src/main/java/org/elasticsearch/protocol/xpack/migration/IndexUpgradeInfoRequest.java

@@ -0,0 +1,98 @@
+/*
+ * 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.protocol.xpack.migration;
+
+import org.elasticsearch.action.ActionRequestValidationException;
+import org.elasticsearch.action.IndicesRequest;
+import org.elasticsearch.action.support.IndicesOptions;
+import org.elasticsearch.action.support.master.MasterNodeReadRequest;
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Objects;
+
+public class IndexUpgradeInfoRequest extends MasterNodeReadRequest<IndexUpgradeInfoRequest> implements IndicesRequest.Replaceable {
+
+    private String[] indices = Strings.EMPTY_ARRAY;
+    private IndicesOptions indicesOptions = IndicesOptions.fromOptions(false, true, true, true);
+
+    public IndexUpgradeInfoRequest(String... indices) {
+        indices(indices);
+    }
+
+    public IndexUpgradeInfoRequest(StreamInput in) throws IOException {
+        super(in);
+        indices = in.readStringArray();
+        indicesOptions = IndicesOptions.readIndicesOptions(in);
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        super.writeTo(out);
+        out.writeStringArray(indices);
+        indicesOptions.writeIndicesOptions(out);
+    }
+
+    @Override
+    public String[] indices() {
+        return indices;
+    }
+
+    @Override
+    public IndexUpgradeInfoRequest indices(String... indices) {
+        this.indices = Objects.requireNonNull(indices, "indices cannot be null");
+        return this;
+    }
+
+    @Override
+    public IndicesOptions indicesOptions() {
+        return indicesOptions;
+    }
+
+    public void indicesOptions(IndicesOptions indicesOptions) {
+        this.indicesOptions = indicesOptions;
+    }
+
+    @Override
+    public ActionRequestValidationException validate() {
+        return null;
+    }
+
+    @Override
+    public void readFrom(StreamInput in) throws IOException {
+        throw new UnsupportedOperationException("usage of Streamable is to be replaced by Writeable");
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        IndexUpgradeInfoRequest request = (IndexUpgradeInfoRequest) o;
+        return Arrays.equals(indices, request.indices) &&
+                Objects.equals(indicesOptions.toString(), request.indicesOptions.toString());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(Arrays.hashCode(indices), indicesOptions.toString());
+    }
+}

x-pack/protocol/src/main/java/org/elasticsearch/protocol/xpack/migration/IndexUpgradeInfoResponse.java

@@ -0,0 +1,133 @@
+/*
+ * 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.protocol.xpack.migration;
+
+import org.elasticsearch.action.ActionResponse;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.ToXContentObject;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Objects;
+import java.util.stream.Collectors;
+
+import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
+
+public class IndexUpgradeInfoResponse extends ActionResponse implements ToXContentObject {
+
+    private static final ParseField INDICES = new ParseField("indices");
+    private static final ParseField ACTION_REQUIRED = new ParseField("action_required");
+
+    private static final ConstructingObjectParser<IndexUpgradeInfoResponse, String> PARSER =
+        new ConstructingObjectParser<>("IndexUpgradeInfoResponse",
+            true,
+            (a, c) -> {
+            @SuppressWarnings("unchecked")
+                Map<String, Object> map = (Map<String, Object>)a[0];
+                Map<String, UpgradeActionRequired> actionsRequired = map.entrySet().stream()
+                    .filter(e -> {
+                        if (e.getValue() instanceof Map == false) {
+                            return false;
+                        }
+                        @SuppressWarnings("unchecked")
+                        Map<String, Object> value =(Map<String, Object>)e.getValue();
+                        return value.containsKey(ACTION_REQUIRED.getPreferredName());
+                    })
+                    .collect(Collectors.toMap(
+                        Map.Entry::getKey,
+                        e -> {
+                            @SuppressWarnings("unchecked")
+                            Map<String, Object> value = (Map<String, Object>) e.getValue();
+                            return UpgradeActionRequired.fromString((String)value.get(ACTION_REQUIRED.getPreferredName()));
+                        }
+                ));
+                return new IndexUpgradeInfoResponse(actionsRequired);
+            });
+
+    static {
+        PARSER.declareObject(constructorArg(), (p, c) -> p.map(), INDICES);
+    }
+
+
+    private Map<String, UpgradeActionRequired> actions;
+
+    public IndexUpgradeInfoResponse() {
+
+    }
+
+    public IndexUpgradeInfoResponse(Map<String, UpgradeActionRequired> actions) {
+        this.actions = actions;
+    }
+
+    @Override
+    public void readFrom(StreamInput in) throws IOException {
+        super.readFrom(in);
+        actions = in.readMap(StreamInput::readString, UpgradeActionRequired::readFromStream);
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        super.writeTo(out);
+        out.writeMap(actions, StreamOutput::writeString, (out1, value) -> value.writeTo(out1));
+    }
+
+    public Map<String, UpgradeActionRequired> getActions() {
+        return actions;
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject();
+        {
+            builder.startObject(INDICES.getPreferredName());
+            for (Map.Entry<String, UpgradeActionRequired> entry : actions.entrySet()) {
+                builder.startObject(entry.getKey());
+                {
+                    builder.field(ACTION_REQUIRED.getPreferredName(), entry.getValue().toString());
+                }
+                builder.endObject();
+            }
+            builder.endObject();
+        }
+        builder.endObject();
+        return builder;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        IndexUpgradeInfoResponse response = (IndexUpgradeInfoResponse) o;
+        return Objects.equals(actions, response.actions);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(actions);
+    }
+
+    public static IndexUpgradeInfoResponse fromXContent(XContentParser parser) {
+        return PARSER.apply(parser, null);
+    }
+}

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/upgrade/UpgradeActionRequired.java → x-pack/protocol/src/main/java/org/elasticsearch/protocol/xpack/migration/UpgradeActionRequired.java

@@ -1,9 +1,22 @@
 /*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License;
- * you may not use this file except in compliance with the Elastic License.
+ * 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.xpack.core.upgrade;
+package org.elasticsearch.protocol.xpack.migration;
 
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;

x-pack/protocol/src/main/java/org/elasticsearch/protocol/xpack/migration/package-info.java

@@ -0,0 +1,24 @@
+/*
+ * 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.
+ */
+
+/**
+ * Request and Response objects for the default distribution's Migration
+ * APIs.
+ */
+package org.elasticsearch.protocol.xpack.migration;

x-pack/protocol/src/test/java/org/elasticsearch/protocol/xpack/migration/IndexUpgradeInfoRequestTests.java

@@ -0,0 +1,50 @@
+/*
+ * 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.protocol.xpack.migration;
+
+import org.elasticsearch.action.support.IndicesOptions;
+import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.test.AbstractWireSerializingTestCase;
+
+public class IndexUpgradeInfoRequestTests extends AbstractWireSerializingTestCase<IndexUpgradeInfoRequest> {
+    @Override
+    protected IndexUpgradeInfoRequest createTestInstance() {
+        int indexCount = randomInt(4);
+        String[] indices = new String[indexCount];
+        for (int i = 0; i < indexCount; i++) {
+            indices[i] = randomAlphaOfLength(10);
+        }
+        IndexUpgradeInfoRequest request = new IndexUpgradeInfoRequest(indices);
+        if (randomBoolean()) {
+            request.indicesOptions(IndicesOptions.fromOptions(randomBoolean(), randomBoolean(), randomBoolean(), randomBoolean()));
+        }
+        return request;
+    }
+
+    @Override
+    protected Writeable.Reader<IndexUpgradeInfoRequest> instanceReader() {
+        return IndexUpgradeInfoRequest::new;
+    }
+
+    public void testNullIndices() {
+        expectThrows(NullPointerException.class, () -> new IndexUpgradeInfoRequest((String[])null));
+        expectThrows(NullPointerException.class, () -> new IndexUpgradeInfoRequest().indices((String[])null));
+    }
+}

x-pack/protocol/src/test/java/org/elasticsearch/protocol/xpack/migration/IndexUpgradeInfoResponseTests.java

@@ -0,0 +1,68 @@
+/*
+ * 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.protocol.xpack.migration;
+
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.test.AbstractStreamableXContentTestCase;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+public class IndexUpgradeInfoResponseTests extends AbstractStreamableXContentTestCase<IndexUpgradeInfoResponse> {
+    @Override
+    protected IndexUpgradeInfoResponse doParseInstance(XContentParser parser) {
+        return IndexUpgradeInfoResponse.fromXContent(parser);
+    }
+
+    @Override
+    protected IndexUpgradeInfoResponse createBlankInstance() {
+        return new IndexUpgradeInfoResponse();
+    }
+
+    @Override
+    protected IndexUpgradeInfoResponse createTestInstance() {
+        return randomIndexUpgradeInfoResponse(randomIntBetween(0, 10));
+    }
+
+    private static IndexUpgradeInfoResponse randomIndexUpgradeInfoResponse(int numIndices) {
+        Map<String, UpgradeActionRequired> actions = new HashMap<>();
+        for (int i = 0; i < numIndices; i++) {
+            actions.put(randomAlphaOfLength(5), randomFrom(UpgradeActionRequired.values()));
+        }
+        return new IndexUpgradeInfoResponse(actions);
+    }
+
+    @Override
+    protected IndexUpgradeInfoResponse mutateInstance(IndexUpgradeInfoResponse instance) {
+        if (instance.getActions().size() == 0) {
+            return randomIndexUpgradeInfoResponse(1);
+        }
+        Map<String, UpgradeActionRequired> actions = new HashMap<>(instance.getActions());
+        if (randomBoolean()) {
+            Iterator<Map.Entry<String, UpgradeActionRequired>> iterator = actions.entrySet().iterator();
+            iterator.next();
+            iterator.remove();
+        } else {
+            actions.put(randomAlphaOfLength(5), randomFrom(UpgradeActionRequired.values()));
+        }
+        return new IndexUpgradeInfoResponse(actions);
+    }
+}