Marvel: Restore cluster_state.nodes

Original commit: elastic/x-pack-elasticsearch@7cf33baf2a

elasticsearch/x-pack/marvel/src/main/java/org/elasticsearch/marvel/agent/renderer/cluster/ClusterStateRenderer.java

@@ -22,6 +22,7 @@ public class ClusterStateRenderer extends AbstractRenderer<ClusterStateMarvelDoc
             "cluster_state.master_node",
             "cluster_state.state_uuid",
             "cluster_state.status",
+            "cluster_state.nodes",
     };
 
     public ClusterStateRenderer() {

elasticsearch/x-pack/marvel/src/main/resources/marvel_index_template.json

@@ -186,6 +186,9 @@
               "type": "string",
               "index": "not_analyzed"
             },
+            "nodes": {
+              "enabled": false
+            },
             "shards": {
               "type": "object"
             }

elasticsearch/x-pack/marvel/src/test/java/org/elasticsearch/marvel/agent/collector/cluster/ClusterStateCollectorTests.java

@@ -170,6 +170,7 @@ public class ClusterStateCollectorTests extends AbstractCollectorTestCase {
                 case ClusterStateCollector.TYPE:
                     ClusterStateMarvelDoc clusterStateMarvelDoc = (ClusterStateMarvelDoc) marvelDoc;
                     assertThat(clusterStateMarvelDoc.getClusterState().getRoutingTable().allShards(), hasSize(nbShards));
+                    assertThat(clusterStateMarvelDoc.getClusterState().getNodes().getSize(), equalTo(internalCluster().size()));
                     break;
 
                 case ClusterStateCollector.NODES_TYPE:

elasticsearch/x-pack/marvel/src/test/resources/samples/cluster_state.json

@@ -5,6 +5,15 @@
     "status": "yellow",
     "version": 14,
     "state_uuid": "lj0hNoO9QaeNa1eR2ukktQ",
-    "master_node": "__node_id__"
+    "master_node": "__node_id__",
+    "nodes": {
+      "__node_id__": {
+        "name": "Box",
+        "transport_address": "inet[/127.0.0.1:9300]",
+        "attributes": {
+          "local": "true"
+        }
+      }
+    }
   }
 }