Add the hostname to the node info

src/main/java/org/elasticsearch/action/admin/cluster/node/info/NodeInfo.java

@@ -44,6 +44,9 @@ public class NodeInfo extends NodeOperationResponse {
 
     private ImmutableMap<String, String> serviceAttributes;
 
+    @Nullable
+    private String hostname;
+
     private Settings settings;
 
     private OsInfo os;
@@ -61,10 +64,11 @@ public class NodeInfo extends NodeOperationResponse {
     NodeInfo() {
     }
 
-    public NodeInfo(DiscoveryNode node, ImmutableMap<String, String> serviceAttributes, Settings settings,
+    public NodeInfo(String hostname, DiscoveryNode node, ImmutableMap<String, String> serviceAttributes, Settings settings,
                     OsInfo os, ProcessInfo process, JvmInfo jvm, NetworkInfo network,
                     TransportInfo transport, @Nullable HttpInfo http) {
         super(node);
+        this.hostname = hostname;
         this.serviceAttributes = serviceAttributes;
         this.settings = settings;
         this.os = os;
@@ -75,6 +79,22 @@ public NodeInfo(DiscoveryNode node, ImmutableMap<String, String> serviceAttribut
         this.http = http;
     }
 
+    /**
+     * System's hostname. <code>null</code> in case of UnknownHostException
+     */
+    @Nullable
+    public String hostname() {
+        return this.hostname;
+    }
+
+    /**
+     * System's hostname. <code>null</code> in case of UnknownHostException
+     */
+    @Nullable
+    public String getHostname() {
+        return hostname();
+    }
+
     /**
      * The service attributes of the node.
      */
@@ -184,6 +204,9 @@ public static NodeInfo readNodeInfo(StreamInput in) throws IOException {
     @Override
     public void readFrom(StreamInput in) throws IOException {
         super.readFrom(in);
+        if (in.readBoolean()) {
+            hostname = in.readUTF();
+        }
         ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
         int size = in.readVInt();
         for (int i = 0; i < size; i++) {
@@ -214,6 +237,12 @@ public void readFrom(StreamInput in) throws IOException {
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
+        if (hostname == null) {
+            out.writeBoolean(false);
+        } else {
+            out.writeBoolean(true);
+            out.writeUTF(hostname);
+        }
         out.writeVInt(serviceAttributes.size());
         for (Map.Entry<String, String> entry : serviceAttributes.entrySet()) {
             out.writeUTF(entry.getKey());

src/main/java/org/elasticsearch/node/service/NodeService.java

@@ -19,6 +19,8 @@
 
 package org.elasticsearch.node.service;
 
+import java.net.InetAddress;
+
 import com.google.common.collect.ImmutableMap;
 import org.elasticsearch.action.admin.cluster.node.info.NodeInfo;
 import org.elasticsearch.action.admin.cluster.node.stats.NodeStats;
@@ -27,6 +29,7 @@
 import org.elasticsearch.common.collect.MapBuilder;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.network.NetworkUtils;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.discovery.Discovery;
 import org.elasticsearch.http.HttpServer;
@@ -51,6 +54,9 @@ public class NodeService extends AbstractComponent {
 
     private volatile ImmutableMap<String, String> serviceAttributes = ImmutableMap.of();
 
+    @Nullable
+    private String hostname;
+
     @Inject
     public NodeService(Settings settings, MonitorService monitorService, Discovery discovery, ClusterService clusterService, TransportService transportService, IndicesService indicesService) {
         super(settings);
@@ -59,6 +65,10 @@ public NodeService(Settings settings, MonitorService monitorService, Discovery d
         this.transportService = transportService;
         this.indicesService = indicesService;
         discovery.setNodeService(this);
+        InetAddress address = NetworkUtils.getLocalAddress();
+        if (address != null) {
+            this.hostname = address.getHostName();
+        }
     }
 
     public void setHttpServer(@Nullable HttpServer httpServer) {
@@ -91,7 +101,7 @@ public ImmutableMap<String, String> attributes() {
     }
 
     public NodeInfo info() {
-        return new NodeInfo(clusterService.state().nodes().localNode(), serviceAttributes, settings,
+        return new NodeInfo(hostname, clusterService.state().nodes().localNode(), serviceAttributes, settings,
                 monitorService.osService().info(), monitorService.processService().info(),
                 monitorService.jvmService().info(), monitorService.networkService().info(),
                 transportService.info(), httpServer == null ? null : httpServer.info());

src/main/java/org/elasticsearch/rest/action/admin/cluster/node/info/RestNodesInfoAction.java

@@ -73,6 +73,10 @@ public void onResponse(NodesInfoResponse result) {
                         builder.field("name", nodeInfo.node().name(), XContentBuilder.FieldCaseConversion.NONE);
                         builder.field("transport_address", nodeInfo.node().address().toString());
 
+                        if (nodeInfo.hostname() != null) {
+                            builder.field("hostname", nodeInfo.hostname(), XContentBuilder.FieldCaseConversion.NONE);
+                        }
+
                         for (Map.Entry<String, String> nodeAttribute : nodeInfo.serviceAttributes().entrySet()) {
                             builder.field(nodeAttribute.getKey(), nodeAttribute.getValue());
                         }