Remove deprecated endpoints containing _xpack. (#48170)

The endpoints with `_xpack` in their path were deprecated in 7.x and can now be
removed. This commit removes deprecated endpoints for the following APIs:
* deprecation
* graph
* license
* monitoring
* rollup
* SQL
* watcher

Author: jtibshirani

docs/reference/migration/migrate_8_0.asciidoc

@@ -50,6 +50,16 @@ Indices created in Elasticsearch 6.x or before will need to be reindexed with
 Elasticsearch 7.x in order to be readable by Elasticsearch 8.x.
 
 =========================================
+
+[float]
+==== REST endpoints containing `_xpack`
+
+In 7.0, we deprecated REST endpoints that contain `_xpack` in their path. These
+endpoints are now removed in 8.0. Each endpoint that was deprecated and removed
+is replaced with a new endpoint that does not contain `_xpack`. As an example,
+`/{index}/_xpack/graph/_explore` is replaced by `/{index}/_graph/explore`.
+
+
 // end::notable-breaking-changes[]
 
 include::migrate_8_0/analysis.asciidoc[]

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

@@ -6,9 +6,7 @@
 
 package org.elasticsearch.license;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.protocol.xpack.license.DeleteLicenseRequest;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
@@ -21,13 +19,8 @@
 
 public class RestDeleteLicenseAction extends BaseRestHandler {
 
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(LogManager.getLogger(RestDeleteLicenseAction.class));
-
     RestDeleteLicenseAction(RestController controller) {
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-                DELETE, "/_license", this,
-                DELETE,  "/_xpack/license", deprecationLogger);
+        controller.registerHandler(DELETE, "/_license", this);
     }
 
     @Override

x-pack/plugin/core/src/main/java/org/elasticsearch/license/RestGetBasicStatus.java

@@ -6,9 +6,7 @@
 
 package org.elasticsearch.license;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -18,13 +16,8 @@
 
 public class RestGetBasicStatus extends BaseRestHandler {
 
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(LogManager.getLogger(RestGetBasicStatus.class));
-
     RestGetBasicStatus(RestController controller) {
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-                GET, "/_license/basic_status", this,
-                GET, "/_xpack/license/basic_status", deprecationLogger);
+        controller.registerHandler(GET, "/_license/basic_status", this);
     }
 
     @Override

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

@@ -6,9 +6,7 @@
 
 package org.elasticsearch.license;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.protocol.xpack.license.GetLicenseRequest;
@@ -29,13 +27,8 @@
 
 public class RestGetLicenseAction extends BaseRestHandler {
 
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(LogManager.getLogger(RestGetLicenseAction.class));
-
     RestGetLicenseAction(RestController controller) {
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-                GET, "/_license", this,
-                GET, "/_xpack/license", deprecationLogger);
+        controller.registerHandler(GET, "/_license", this);
     }
 
     @Override

x-pack/plugin/core/src/main/java/org/elasticsearch/license/RestGetTrialStatus.java

@@ -6,9 +6,7 @@
 
 package org.elasticsearch.license;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -18,13 +16,8 @@
 
 public class RestGetTrialStatus extends BaseRestHandler {
 
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(LogManager.getLogger(RestGetTrialStatus.class));
-
     RestGetTrialStatus(RestController controller) {
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-                GET, "/_license/trial_status", this,
-                GET, "/_xpack/license/trial_status", deprecationLogger);
+        controller.registerHandler(GET, "/_license/trial_status", this);
     }
 
     @Override

x-pack/plugin/core/src/main/java/org/elasticsearch/license/RestPostStartBasicLicense.java

@@ -6,9 +6,7 @@
 
 package org.elasticsearch.license;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -20,13 +18,8 @@
 
 public class RestPostStartBasicLicense extends BaseRestHandler {
 
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(LogManager.getLogger(RestPostStartBasicLicense.class));
-
     RestPostStartBasicLicense(RestController controller) {
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-                POST, "/_license/start_basic", this,
-                POST, "/_xpack/license/start_basic", deprecationLogger);
+        controller.registerHandler(POST, "/_license/start_basic", this);
     }
 
     @Override

x-pack/plugin/core/src/main/java/org/elasticsearch/license/RestPostStartTrialLicense.java

@@ -6,9 +6,7 @@
 
 package org.elasticsearch.license;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.BytesRestResponse;
@@ -24,13 +22,8 @@
 
 public class RestPostStartTrialLicense extends BaseRestHandler {
 
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(LogManager.getLogger(RestPostStartTrialLicense.class));
-
     RestPostStartTrialLicense(RestController controller) {
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-                POST, "/_license/start_trial", this,
-                POST, "/_xpack/license/start_trial", deprecationLogger);
+        controller.registerHandler(POST, "/_license/start_trial", this);
     }
 
     @Override

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

@@ -6,9 +6,7 @@
 
 package org.elasticsearch.license;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -21,18 +19,10 @@
 
 public class RestPutLicenseAction extends BaseRestHandler {
 
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(LogManager.getLogger(RestPutLicenseAction.class));
-
     RestPutLicenseAction(RestController controller) {
         // TODO: remove POST endpoint?
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-                POST, "/_license", this,
-                POST, "/_xpack/license", deprecationLogger);
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-                PUT, "/_license", this,
-                PUT,  "/_xpack/license", deprecationLogger);
+        controller.registerHandler(POST, "/_license", this);
+        controller.registerHandler(PUT, "/_license", this);
     }
 
     @Override

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ssl/rest/RestGetCertificateInfoAction.java

@@ -5,9 +5,7 @@
  */
 package org.elasticsearch.xpack.core.ssl.rest;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.BytesRestResponse;
@@ -27,14 +25,8 @@
  */
 public class RestGetCertificateInfoAction extends BaseRestHandler {
 
-    private static final DeprecationLogger deprecationLogger =
-        new DeprecationLogger(LogManager.getLogger(RestGetCertificateInfoAction.class));
-
     public RestGetCertificateInfoAction(RestController controller) {
-        // TODO: remove deprecated endpoint in 8.0.0
-        controller.registerWithDeprecatedHandler(
-            GET, "/_ssl/certificates", this,
-            GET, "/_xpack/ssl/certificates", deprecationLogger);
+        controller.registerHandler(GET, "/_ssl/certificates", this);
     }
 
     @Override

x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/RestDeprecationInfoAction.java

@@ -9,7 +9,6 @@
 import org.apache.logging.log4j.Logger;
 import org.elasticsearch.client.node.NodeClient;
 import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -21,15 +20,10 @@
 
 public class RestDeprecationInfoAction extends BaseRestHandler {
     private static final Logger logger = LogManager.getLogger(RestDeprecationInfoAction.class);
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(logger);
 
     public RestDeprecationInfoAction(RestController controller) {
-        controller.registerWithDeprecatedHandler(
-            RestRequest.Method.GET, "/_migration/deprecations", this,
-            RestRequest.Method.GET, "/_xpack/migration/deprecations", deprecationLogger);
-        controller.registerWithDeprecatedHandler(
-            RestRequest.Method.GET, "/{index}/_migration/deprecations", this,
-            RestRequest.Method.GET, "/{index}/_xpack/migration/deprecations", deprecationLogger);
+        controller.registerHandler(RestRequest.Method.GET, "/_migration/deprecations", this);
+        controller.registerHandler(RestRequest.Method.GET, "/{index}/_migration/deprecations", this);
     }
 
     @Override