[License] Log Deprecation Warnings for old API usage

This makes use of the registerAsDeprecatedHandler method to automatically warn users when they're using deprecated functionality.

This will also automatically provide a Warning header for anyone using HTTP clients (though they have to be looking for it...).

- This also adds deprecated `/_licenses` variants of the endpoint. Users are consistently making that mistake, and it's easy enough to support this way. Can remove it if people disagree though.

License portion only

Original commit: elastic/x-pack-elasticsearch@431c871fcf

elasticsearch/x-pack/license-plugin/src/main/java/org/elasticsearch/license/plugin/rest/RestDeleteLicenseAction.java

@@ -5,29 +5,39 @@
  */
 package org.elasticsearch.license.plugin.rest;
 
-import org.elasticsearch.client.node.NodeClient;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.license.plugin.action.delete.DeleteLicenseAction;
 import org.elasticsearch.license.plugin.action.delete.DeleteLicenseRequest;
-import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestChannel;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.action.support.AcknowledgedRestListener;
+import org.elasticsearch.xpack.XPackClient;
+import org.elasticsearch.xpack.rest.XPackRestHandler;
 
 import static org.elasticsearch.rest.RestRequest.Method.DELETE;
 
-public class RestDeleteLicenseAction extends BaseRestHandler {
+public class RestDeleteLicenseAction extends XPackRestHandler {
 
     @Inject
     public RestDeleteLicenseAction(Settings settings, RestController controller) {
         super(settings);
-        controller.registerHandler(DELETE, "/_xpack/license", this);
+        // @deprecated Remove deprecations in 6.0
+        controller.registerWithDeprecatedHandler(DELETE, URI_BASE + "/_license", this,
+                                                 DELETE, "/_license", deprecationLogger);
+
+        // Remove _licenses support entirely in 6.0
+        controller.registerAsDeprecatedHandler(DELETE, "/_licenses", this,
+                                               "[DELETE /_licenses] is deprecated! Use " +
+                                               "[DELETE /_xpack/license] instead.",
+                                               deprecationLogger);
     }
 
     @Override
-    public void handleRequest(final RestRequest request, final RestChannel channel, final NodeClient client) {
+    public void handleRequest(final RestRequest request, final RestChannel channel, final XPackClient client) {
-        client.admin().cluster().execute(DeleteLicenseAction.INSTANCE, new DeleteLicenseRequest(), new AcknowledgedRestListener<>(channel));
+        client.es().admin().cluster().execute(DeleteLicenseAction.INSTANCE,
+                                              new DeleteLicenseRequest(),
+                                              new AcknowledgedRestListener<>(channel));
     }
 }

elasticsearch/x-pack/license-plugin/src/main/java/org/elasticsearch/license/plugin/rest/RestGetLicenseAction.java

@@ -5,7 +5,6 @@
  */
 package org.elasticsearch.license.plugin.rest;
 
-import org.elasticsearch.client.node.NodeClient;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.ToXContent;
@@ -14,13 +13,14 @@ import org.elasticsearch.license.core.License;
 import org.elasticsearch.license.plugin.action.get.GetLicenseAction;
 import org.elasticsearch.license.plugin.action.get.GetLicenseRequest;
 import org.elasticsearch.license.plugin.action.get.GetLicenseResponse;
-import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.BytesRestResponse;
 import org.elasticsearch.rest.RestChannel;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.RestResponse;
 import org.elasticsearch.rest.action.support.RestBuilderListener;
+import org.elasticsearch.xpack.XPackClient;
+import org.elasticsearch.xpack.rest.XPackRestHandler;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -29,12 +29,20 @@ import static org.elasticsearch.rest.RestRequest.Method.GET;
 import static org.elasticsearch.rest.RestStatus.NOT_FOUND;
 import static org.elasticsearch.rest.RestStatus.OK;
 
-public class RestGetLicenseAction extends BaseRestHandler {
+public class RestGetLicenseAction extends XPackRestHandler {
 
     @Inject
     public RestGetLicenseAction(Settings settings, RestController controller) {
         super(settings);
-        controller.registerHandler(GET, "/_xpack/license", this);
+        // @deprecated Remove deprecations in 6.0
+        controller.registerWithDeprecatedHandler(GET,  URI_BASE + "/_license", this,
+                                                 GET, "/_license", deprecationLogger);
+
+        // Remove _licenses support entirely in 6.0
+        controller.registerAsDeprecatedHandler(GET, "/_licenses", this,
+                                               "[GET /_licenses] is deprecated! Use " +
+                                               "[GET /_xpack/license] instead.",
+                                               deprecationLogger);
     }
 
     /**
@@ -44,14 +52,14 @@ public class RestGetLicenseAction extends BaseRestHandler {
      * The licenses are sorted by latest issue_date
      */
     @Override
-    public void handleRequest(final RestRequest request, final RestChannel channel, final NodeClient client) {
+    public void handleRequest(final RestRequest request, final RestChannel channel, final XPackClient client) {
         final Map<String, String> overrideParams = new HashMap<>(2);
         overrideParams.put(License.REST_VIEW_MODE, "true");
         overrideParams.put(License.LICENSE_VERSION_MODE, String.valueOf(License.VERSION_CURRENT));
         final ToXContent.Params params = new ToXContent.DelegatingMapParams(overrideParams, request);
         GetLicenseRequest getLicenseRequest = new GetLicenseRequest();
         getLicenseRequest.local(request.paramAsBoolean("local", getLicenseRequest.local()));
-        client.admin().cluster().execute(GetLicenseAction.INSTANCE, getLicenseRequest,
+        client.es().admin().cluster().execute(GetLicenseAction.INSTANCE, getLicenseRequest,
                 new RestBuilderListener<GetLicenseResponse>(channel) {
                     @Override
                     public RestResponse buildResponse(GetLicenseResponse response, XContentBuilder builder) throws Exception {

elasticsearch/x-pack/license-plugin/src/main/java/org/elasticsearch/license/plugin/rest/RestPutLicenseAction.java

@@ -5,7 +5,6 @@
  */
 package org.elasticsearch.license.plugin.rest;
 
-import org.elasticsearch.client.node.NodeClient;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.ToXContent;
@@ -13,7 +12,6 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.license.plugin.action.put.PutLicenseAction;
 import org.elasticsearch.license.plugin.action.put.PutLicenseRequest;
 import org.elasticsearch.license.plugin.action.put.PutLicenseResponse;
-import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.BytesRestResponse;
 import org.elasticsearch.rest.RestChannel;
 import org.elasticsearch.rest.RestController;
@@ -21,25 +19,40 @@ import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.RestResponse;
 import org.elasticsearch.rest.RestStatus;
 import org.elasticsearch.rest.action.support.RestBuilderListener;
+import org.elasticsearch.xpack.XPackClient;
+import org.elasticsearch.xpack.rest.XPackRestHandler;
 
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 import static org.elasticsearch.rest.RestRequest.Method.PUT;
 
-public class RestPutLicenseAction extends BaseRestHandler {
+public class RestPutLicenseAction extends XPackRestHandler {
 
     @Inject
     public RestPutLicenseAction(Settings settings, RestController controller) {
         super(settings);
-        controller.registerHandler(PUT, "/_xpack/license", this);
+        // @deprecated Remove deprecations in 6.0
-        controller.registerHandler(POST, "/_xpack/license", this);
+        controller.registerWithDeprecatedHandler(POST, URI_BASE + "/_license", this,
+                                                 POST, "/_license", deprecationLogger);
+        controller.registerWithDeprecatedHandler(PUT, URI_BASE + "/_license", this,
+                                                 PUT, "/_license", deprecationLogger);
+
+        // Remove _licenses support entirely in 6.0
+        controller.registerAsDeprecatedHandler(POST, "/_licenses", this,
+                                               "[POST /_licenses] is deprecated! Use " +
+                                               "[POST /_xpack/license] instead.",
+                                               deprecationLogger);
+        controller.registerAsDeprecatedHandler(PUT, "/_licenses", this,
+                                               "[PUT /_licenses] is deprecated! Use " +
+                                               "[PUT /_xpack/license] instead.",
+                                               deprecationLogger);
     }
 
     @Override
-    public void handleRequest(final RestRequest request, final RestChannel channel, final NodeClient client) {
+    public void handleRequest(final RestRequest request, final RestChannel channel, final XPackClient client) {
         PutLicenseRequest putLicenseRequest = new PutLicenseRequest();
         putLicenseRequest.license(request.content().utf8ToString());
         putLicenseRequest.acknowledge(request.paramAsBoolean("acknowledge", false));
-        client.admin().cluster().execute(PutLicenseAction.INSTANCE, putLicenseRequest,
+        client.es().admin().cluster().execute(PutLicenseAction.INSTANCE, putLicenseRequest,
                 new RestBuilderListener<PutLicenseResponse>(channel) {
                     @Override
                     public RestResponse buildResponse(PutLicenseResponse response, XContentBuilder builder) throws Exception {