Disable field stats cache if field level security

Field level security poisons that cache.

Closes elastic/elasticsearch#2528

Original commit: elastic/x-pack-elasticsearch@12ca4a2ef4

elasticsearch/x-pack/shield/src/main/java/org/elasticsearch/shield/action/ShieldActionModule.java

@@ -9,6 +9,7 @@ import org.elasticsearch.common.inject.multibindings.Multibinder;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.shield.action.filter.ShieldActionFilter;
 import org.elasticsearch.shield.action.interceptor.BulkRequestInterceptor;
+import org.elasticsearch.shield.action.interceptor.FieldStatsRequestInterceptor;
 import org.elasticsearch.shield.action.interceptor.RealtimeRequestInterceptor;
 import org.elasticsearch.shield.action.interceptor.RequestInterceptor;
 import org.elasticsearch.shield.action.interceptor.SearchRequestInterceptor;
@@ -34,5 +35,6 @@ public class ShieldActionModule extends AbstractShieldModule.Node {
         multibinder.addBinding().to(SearchRequestInterceptor.class);
         multibinder.addBinding().to(UpdateRequestInterceptor.class);
         multibinder.addBinding().to(BulkRequestInterceptor.class);
+        multibinder.addBinding().to(FieldStatsRequestInterceptor.class);
     }
 }

elasticsearch/x-pack/shield/src/main/java/org/elasticsearch/shield/action/interceptor/FieldAndDocumentLevelSecurityRequestInterceptor.java

@@ -47,12 +47,14 @@ public abstract class FieldAndDocumentLevelSecurityRequestInterceptor<Request> e
             for (String index : indicesRequest.indices()) {
                 IndicesAccessControl.IndexAccessControl indexAccessControl = indicesAccessControl.getIndexPermissions(index);
                 if (indexAccessControl != null) {
-                    boolean fls = indexAccessControl.getFields() != null;
-                    boolean dls = indexAccessControl.getQueries() != null;
-                    if (fls || dls) {
-                        logger.debug("intercepted request for index [{}] with field level or document level security enabled, " +
-                                "disabling features", index);
-                        disableFeatures(request);
+                    boolean fieldLevelSecurityEnabled = indexAccessControl.getFields() != null;
+                    boolean documentLevelSecurityEnabled = indexAccessControl.getQueries() != null;
+                    if (fieldLevelSecurityEnabled || documentLevelSecurityEnabled) {
+                        if (logger.isDebugEnabled()) {
+                            logger.debug("intercepted request for index [{}] with field level [{}] or document level [{}] security "
+                                    + "enabled, disabling features", index, fieldLevelSecurityEnabled, documentLevelSecurityEnabled);
+                        }
+                        disableFeatures(request, fieldLevelSecurityEnabled, documentLevelSecurityEnabled);
                         return;
                     }
                 }
@@ -62,6 +64,6 @@ public abstract class FieldAndDocumentLevelSecurityRequestInterceptor<Request> e
         }
     }
 
-    protected abstract void disableFeatures(Request request);
+    protected abstract void disableFeatures(Request request, boolean fieldLevelSecurityEnabled, boolean documentLevelSecurityEnabled);
 
 }

elasticsearch/x-pack/shield/src/main/java/org/elasticsearch/shield/action/interceptor/FieldStatsRequestInterceptor.java

@@ -0,0 +1,34 @@
+/*
+ * 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.shield.action.interceptor;
+
+import org.elasticsearch.action.fieldstats.FieldStatsRequest;
+import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.transport.TransportRequest;
+
+/**
+ * Intercepts requests to shards to field level stats and strips fields that the user is not allowed to access from the response.
+ */
+public class FieldStatsRequestInterceptor extends FieldAndDocumentLevelSecurityRequestInterceptor<FieldStatsRequest> {
+    @Inject
+    public FieldStatsRequestInterceptor(Settings settings, ThreadPool threadPool) {
+        super(settings, threadPool.getThreadContext());
+    }
+
+    @Override
+    public boolean supports(TransportRequest request) {
+        return request instanceof FieldStatsRequest;
+    }
+
+    @Override
+    protected void disableFeatures(FieldStatsRequest request, boolean fieldLevelSecurityEnabled, boolean documentLevelSecurityEnabled) {
+        if (fieldLevelSecurityEnabled) {
+            request.setUseCache(false);
+        }
+    }
+}

elasticsearch/x-pack/shield/src/main/java/org/elasticsearch/shield/action/interceptor/RealtimeRequestInterceptor.java

@@ -23,7 +23,8 @@ public class RealtimeRequestInterceptor extends FieldAndDocumentLevelSecurityReq
     }
 
     @Override
-    protected void disableFeatures(RealtimeRequest realtimeRequest) {
+    protected void disableFeatures(RealtimeRequest realtimeRequest, boolean fieldLevelSecurityEnabled,
+            boolean documentLevelSecurityEnabled) {
         realtimeRequest.realtime(false);
     }
 

elasticsearch/x-pack/shield/src/main/java/org/elasticsearch/shield/action/interceptor/SearchRequestInterceptor.java

@@ -22,7 +22,7 @@ public class SearchRequestInterceptor extends FieldAndDocumentLevelSecurityReque
     }
 
     @Override
-    public void disableFeatures(SearchRequest request) {
+    public void disableFeatures(SearchRequest request, boolean fieldLevelSecurityEnabled, boolean documentLevelSecurityEnabled) {
         request.requestCache(false);
     }
 

elasticsearch/x-pack/shield/src/main/java/org/elasticsearch/shield/action/interceptor/UpdateRequestInterceptor.java

@@ -28,7 +28,7 @@ public class UpdateRequestInterceptor extends FieldAndDocumentLevelSecurityReque
     }
 
     @Override
-    protected void disableFeatures(UpdateRequest updateRequest) {
+    protected void disableFeatures(UpdateRequest updateRequest, boolean fieldLevelSecurityEnabled, boolean documentLevelSecurityEnabled) {
         throw new ElasticsearchSecurityException("Can't execute an update request if field or document level security is enabled",
                 RestStatus.BAD_REQUEST);
     }

elasticsearch/x-pack/shield/src/test/java/org/elasticsearch/integration/FieldLevelSecurityTests.java

@@ -483,7 +483,6 @@ public class FieldLevelSecurityTests extends ShieldIntegTestCase {
         assertThat(response.getResponses()[0].getResponse().getSource().get("field2").toString(), equalTo("value2"));
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/x-plugins/issues/2528")
     public void testFieldStatsApi() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("test")
                         .addMapping("type1", "field1", "type=text", "field2", "type=text", "field3", "type=text")