HDFS-17011. Fix the metric of "HttpPort" at DataNodeInfo (#5657). Contributed by Zhaohui Wang.

Reviewed-by: Inigo Goiri <inigoiri@apache.org>
Signed-off-by: Ayush Saxena <ayushsaxena@apache.org>

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -3435,7 +3435,7 @@ public class DataNode extends ReconfigurableBase
 
   @Override // DataNodeMXBean
   public String getHttpPort(){
-    return this.getConf().get("dfs.datanode.info.port");
+    return String.valueOf(infoPort);
   }
 
   @Override // DataNodeMXBean

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java

@@ -92,6 +92,7 @@ public class TestDataNodeMXBean extends SaslDataTransferTestCase {
       Assert.assertEquals(datanode.getRpcPort(),rpcPort);
       // get attribute "HttpPort"
       String httpPort = (String)mbs.getAttribute(mxbeanName, "HttpPort");
+      Assert.assertNotNull(httpPort);
       Assert.assertEquals(datanode.getHttpPort(),httpPort);
       // get attribute "NamenodeAddresses"
       String namenodeAddresses = (String)mbs.getAttribute(mxbeanName,