Adding initial public and internal serverless scopes to Distributed REST handlers (#94034)

#93607 added the ability to run Elasticsearch in "Serverless" mode,
where access to REST endpoints could be restricted so that the full
Elasticsearch API is not available (since a lot of it does not make
sense in Servlerless). By default no endpoints are available, but they
can be exposed with `ServerlessScope` annotations. This PR follows up on
#93607 by adding PUBLIC and INTERNAL annotations to the rest handlers
owned by the Distributed team. There are several rest endpoints still
under discussion. This PR does not label those, so they remain
unavailable in Serverless mode.

modules/reindex/src/main/java/org/elasticsearch/reindex/RestDeleteByQueryAction.java

@@ -14,6 +14,8 @@ import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.index.reindex.DeleteByQueryAction;
 import org.elasticsearch.index.reindex.DeleteByQueryRequest;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.search.RestSearchAction;
 
 import java.io.IOException;
@@ -24,6 +26,7 @@ import java.util.function.Consumer;
 
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
+@ServerlessScope(Scope.PUBLIC)
 public class RestDeleteByQueryAction extends AbstractBulkByQueryRestHandler<DeleteByQueryRequest, DeleteByQueryAction> {
 
     public RestDeleteByQueryAction() {

modules/reindex/src/main/java/org/elasticsearch/reindex/RestUpdateByQueryAction.java

@@ -14,6 +14,8 @@ import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.index.reindex.UpdateByQueryAction;
 import org.elasticsearch.index.reindex.UpdateByQueryRequest;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.search.RestSearchAction;
 import org.elasticsearch.script.Script;
 
@@ -25,6 +27,7 @@ import java.util.function.Consumer;
 
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
+@ServerlessScope(Scope.PUBLIC)
 public class RestUpdateByQueryAction extends AbstractBulkByQueryRestHandler<UpdateByQueryRequest, UpdateByQueryAction> {
 
     public RestUpdateByQueryAction() {

server/src/main/java/org/elasticsearch/rest/action/admin/cluster/RestClusterAllocationExplainAction.java

@@ -15,6 +15,8 @@ import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.RestResponse;
 import org.elasticsearch.rest.RestStatus;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestBuilderListener;
 import org.elasticsearch.xcontent.ToXContent;
 import org.elasticsearch.xcontent.XContentBuilder;
@@ -29,6 +31,7 @@ import static org.elasticsearch.rest.RestRequest.Method.POST;
 /**
  * Class handling cluster allocation explanation at the REST level
  */
+@ServerlessScope(Scope.INTERNAL)
 public class RestClusterAllocationExplainAction extends BaseRestHandler {
 
     @Override

server/src/main/java/org/elasticsearch/rest/action/admin/cluster/RestClusterHealthAction.java

@@ -18,6 +18,8 @@ import org.elasticsearch.common.Priority;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestStatusToXContentListener;
 
 import java.io.IOException;
@@ -28,6 +30,7 @@ import java.util.Set;
 
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 
+@ServerlessScope(Scope.INTERNAL)
 public class RestClusterHealthAction extends BaseRestHandler {
 
     @Override

server/src/main/java/org/elasticsearch/rest/action/admin/cluster/RestClusterRerouteAction.java

@@ -17,6 +17,8 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.settings.SettingsFilter;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestChunkedToXContentListener;
 import org.elasticsearch.xcontent.ObjectParser;
 import org.elasticsearch.xcontent.ObjectParser.ValueType;
@@ -30,6 +32,7 @@ import java.util.Set;
 import static org.elasticsearch.common.util.set.Sets.addToCopy;
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
+@ServerlessScope(Scope.INTERNAL)
 public class RestClusterRerouteAction extends BaseRestHandler {
 
     private static final Set<String> RESPONSE_PARAMS = addToCopy(Settings.FORMAT_PARAMS, "metric");

server/src/main/java/org/elasticsearch/rest/action/admin/cluster/RestClusterStateAction.java

@@ -24,6 +24,8 @@ import org.elasticsearch.common.xcontent.ChunkedToXContent;
 import org.elasticsearch.common.xcontent.ChunkedToXContentHelper;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestCancellableNodeClient;
 import org.elasticsearch.rest.action.RestChunkedToXContentListener;
 import org.elasticsearch.threadpool.ThreadPool;
@@ -41,6 +43,7 @@ import static java.util.Collections.singletonMap;
 import static org.elasticsearch.common.util.set.Sets.addToCopy;
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 
+@ServerlessScope(Scope.INTERNAL)
 public class RestClusterStateAction extends BaseRestHandler {
 
     private static final Set<String> RESPONSE_PARAMS = addToCopy(Settings.FORMAT_PARAMS, "metric");

server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestResolveIndexAction.java

@@ -14,6 +14,8 @@ import org.elasticsearch.client.internal.node.NodeClient;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestToXContentListener;
 
 import java.io.IOException;
@@ -21,6 +23,7 @@ import java.util.List;
 
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 
+@ServerlessScope(Scope.PUBLIC)
 public class RestResolveIndexAction extends BaseRestHandler {
 
     @Override

server/src/main/java/org/elasticsearch/rest/action/document/RestGetAction.java

@@ -17,6 +17,8 @@ import org.elasticsearch.index.VersionType;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.RestStatus;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestActions;
 import org.elasticsearch.rest.action.RestToXContentListener;
 import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
@@ -29,6 +31,7 @@ import static org.elasticsearch.rest.RestRequest.Method.HEAD;
 import static org.elasticsearch.rest.RestStatus.NOT_FOUND;
 import static org.elasticsearch.rest.RestStatus.OK;
 
+@ServerlessScope(Scope.PUBLIC)
 public class RestGetAction extends BaseRestHandler {
     static final String TYPES_DEPRECATION_MESSAGE = "[types removal] Specifying types in "
         + "document get requests is deprecated, use the /{index}/_doc/{id} endpoint instead.";

server/src/main/java/org/elasticsearch/rest/action/document/RestGetSourceAction.java

@@ -21,6 +21,8 @@ import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestChannel;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.RestResponse;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestResponseListener;
 import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
 import org.elasticsearch.xcontent.XContentBuilder;
@@ -36,6 +38,7 @@ import static org.elasticsearch.rest.RestStatus.OK;
 /**
  * The REST handler for get source and head source APIs.
  */
+@ServerlessScope(Scope.PUBLIC)
 public class RestGetSourceAction extends BaseRestHandler {
     private final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(RestGetSourceAction.class);
     static final String TYPES_DEPRECATION_MESSAGE = "[types removal] Specifying types in get_source and exist_source "

server/src/main/java/org/elasticsearch/rest/action/document/RestMultiGetAction.java

@@ -15,6 +15,8 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestToXContentListener;
 import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
 import org.elasticsearch.xcontent.XContentParser;
@@ -25,6 +27,7 @@ import java.util.List;
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
+@ServerlessScope(Scope.PUBLIC)
 public class RestMultiGetAction extends BaseRestHandler {
     public static final String TYPES_DEPRECATION_MESSAGE = "[types removal] Specifying types in multi get requests is deprecated.";
 

x-pack/plugin/fleet/src/main/java/org/elasticsearch/xpack/fleet/rest/RestFleetMultiSearchAction.java

@@ -15,6 +15,8 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestCancellableNodeClient;
 import org.elasticsearch.rest.action.RestToXContentListener;
 import org.elasticsearch.rest.action.search.RestMultiSearchAction;
@@ -33,6 +35,7 @@ import static org.elasticsearch.common.xcontent.support.XContentMapValues.nodeTi
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
+@ServerlessScope(Scope.INTERNAL)
 public class RestFleetMultiSearchAction extends BaseRestHandler {
 
     private final boolean allowExplicitIndex;

x-pack/plugin/fleet/src/main/java/org/elasticsearch/xpack/fleet/rest/RestFleetSearchAction.java

@@ -15,6 +15,8 @@ import org.elasticsearch.common.Strings;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestCancellableNodeClient;
 import org.elasticsearch.rest.action.RestStatusToXContentListener;
 import org.elasticsearch.rest.action.search.RestSearchAction;
@@ -30,6 +32,7 @@ import java.util.function.IntConsumer;
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
+@ServerlessScope(Scope.INTERNAL)
 public class RestFleetSearchAction extends BaseRestHandler {
 
     private final SearchUsageHolder searchUsageHolder;

x-pack/plugin/fleet/src/main/java/org/elasticsearch/xpack/fleet/rest/RestGetGlobalCheckpointsAction.java

@@ -11,6 +11,8 @@ import org.elasticsearch.client.internal.node.NodeClient;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.Scope;
+import org.elasticsearch.rest.ServerlessScope;
 import org.elasticsearch.rest.action.RestToXContentListener;
 import org.elasticsearch.xpack.fleet.action.GetGlobalCheckpointsAction;
 
@@ -18,6 +20,7 @@ import java.util.List;
 
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 
+@ServerlessScope(Scope.INTERNAL)
 public class RestGetGlobalCheckpointsAction extends BaseRestHandler {
 
     @Override