NETWORKING: http.publish_host Should Contain CNAME

server/src/main/java/org/elasticsearch/http/HttpInfo.java

@@ -19,10 +19,13 @@
 
 package org.elasticsearch.http;
 
+import java.net.InetSocketAddress;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.common.network.NetworkAddress;
 import org.elasticsearch.common.transport.BoundTransportAddress;
+import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.xcontent.ToXContentFragment;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -62,7 +65,16 @@ static final class Fields {
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject(Fields.HTTP);
         builder.array(Fields.BOUND_ADDRESS, (Object[]) address.boundAddresses());
-        builder.field(Fields.PUBLISH_ADDRESS, address.publishAddress().toString());
+        TransportAddress publishAddress = address.publishAddress();
+        InetSocketAddress publishInetAddress = publishAddress.address();
+        String hostString = publishInetAddress.getHostString();
+        final String publishAddressString;
+        if (hostString.equals(NetworkAddress.format(publishInetAddress.getAddress()))) {
+            publishAddressString = publishAddress.toString();
+        } else {
+            publishAddressString = hostString + '/' + publishAddress.toString();
+        }
+        builder.field(Fields.PUBLISH_ADDRESS, publishAddressString);
         builder.humanReadableField(Fields.MAX_CONTENT_LENGTH_IN_BYTES, Fields.MAX_CONTENT_LENGTH, maxContentLength());
         builder.endObject();
         return builder;

server/src/test/java/org/elasticsearch/http/HttpInfoTests.java

@@ -0,0 +1,73 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.http;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.util.Map;
+import org.elasticsearch.common.network.NetworkAddress;
+import org.elasticsearch.common.transport.BoundTransportAddress;
+import org.elasticsearch.common.transport.TransportAddress;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.test.ESTestCase;
+
+public class HttpInfoTests extends ESTestCase {
+
+    public void testCorrectlyDisplayPublishedCname() throws Exception {
+        InetAddress localhost = InetAddress.getByName("localhost");
+        int port = 9200;
+        assertPublishAddress(
+            new HttpInfo(
+                new BoundTransportAddress(
+                    new TransportAddress[]{new TransportAddress(localhost, port)},
+                    new TransportAddress(localhost, port)
+                ), 0L
+            ), "localhost/" + NetworkAddress.format(localhost) + ':' + port
+        );
+    }
+
+    public void testCorrectDisplayPublishedIp() throws Exception {
+        InetAddress localhost = InetAddress.getByName(NetworkAddress.format(InetAddress.getByName("localhost")));
+        int port = 9200;
+        assertPublishAddress(
+            new HttpInfo(
+                new BoundTransportAddress(
+                    new TransportAddress[]{new TransportAddress(localhost, port)},
+                    new TransportAddress(localhost, port)
+                ), 0L
+            ), NetworkAddress.format(localhost) + ':' + port
+        );
+    }
+
+    @SuppressWarnings("unchecked")
+    private void assertPublishAddress(HttpInfo httpInfo, String expected) throws IOException {
+        XContentBuilder builder = XContentFactory.jsonBuilder();
+        builder.startObject();
+        httpInfo.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        builder.endObject();
+        assertEquals(
+            expected,
+            ((Map<String, Object>) createParser(builder).map().get(HttpInfo.Fields.HTTP))
+                .get(HttpInfo.Fields.PUBLISH_ADDRESS)
+        );
+    }
+}