HDFS-15281. Make sure ZKFC uses dfs.namenode.rpc-address to bind to host address (#1964)

Contributed by Dhiraj Hegde.

Signed-off-by: Mingliang Liu <liuml07@apache.org>
Signed-off-by: Inigo Goiri <inigoiri@apache.org>

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ha/ZKFailoverController.java

@@ -318,9 +318,10 @@ public abstract class ZKFailoverController {
     healthMonitor.addServiceStateCallback(new ServiceStateCallBacks());
     healthMonitor.start();
   }
-  
+
   protected void initRPC() throws IOException {
     InetSocketAddress bindAddr = getRpcAddressToBindTo();
+    LOG.info("ZKFC RpcServer binding to {}", bindAddr);
     rpcServer = new ZKFCRpcServer(conf, bindAddr, this, getPolicyProvider());
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSZKFailoverController.java

@@ -111,21 +111,39 @@ public class DFSZKFailoverController extends ZKFailoverController {
   @Override
   protected InetSocketAddress getRpcAddressToBindTo() {
     int zkfcPort = getZkfcPort(conf);
-    return new InetSocketAddress(localTarget.getAddress().getAddress(),
-          zkfcPort);
+    String zkfcBindAddr = getZkfcServerBindHost(conf);
+    if (zkfcBindAddr == null || zkfcBindAddr.isEmpty()) {
+      zkfcBindAddr = localTarget.getAddress().getAddress().getHostAddress();
+    }
+    return new InetSocketAddress(zkfcBindAddr, zkfcPort);
   }
-  
 
   @Override
   protected PolicyProvider getPolicyProvider() {
     return new HDFSPolicyProvider();
   }
-  
+
   static int getZkfcPort(Configuration conf) {
     return conf.getInt(DFSConfigKeys.DFS_HA_ZKFC_PORT_KEY,
         DFSConfigKeys.DFS_HA_ZKFC_PORT_DEFAULT);
   }
-  
+
+  /**
+   * Given a configuration get the bind host that could be used by ZKFC.
+   * We derive it from NN service rpc bind host or NN rpc bind host.
+   *
+   * @param conf input configuration
+   * @return the bind host address found in conf
+   */
+  private static String getZkfcServerBindHost(Configuration conf) {
+    String addr = conf.getTrimmed(
+        DFSConfigKeys.DFS_NAMENODE_SERVICE_RPC_BIND_HOST_KEY);
+    if (addr == null || addr.isEmpty()) {
+      addr = conf.getTrimmed(DFSConfigKeys.DFS_NAMENODE_RPC_BIND_HOST_KEY);
+    }
+    return addr;
+  }
+
   public static DFSZKFailoverController create(Configuration conf) {
     Configuration localNNConf = DFSHAAdmin.addSecurityConfiguration(conf);
     String nsId = DFSUtil.getNamenodeNameServiceId(conf);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/TestDFSZKFailoverController.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.tools;
 
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_SERVICE_RPC_BIND_HOST_KEY;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
@@ -57,6 +58,8 @@ import org.junit.Test;
 import com.google.common.base.Supplier;
 
 public class TestDFSZKFailoverController extends ClientBaseWithFixes {
+  private static final String LOCALHOST_SERVER_ADDRESS = "127.0.0.1";
+  private static final String WILDCARD_ADDRESS = "0.0.0.0";
   private Configuration conf;
   private MiniDFSCluster cluster;
   private TestContext ctx;
@@ -207,6 +210,27 @@ public class TestDFSZKFailoverController extends ClientBaseWithFixes {
     waitForHAState(1, HAServiceState.STANDBY);
   }
 
+  @Test(timeout=30000)
+  public void testWithoutBindAddressSet() throws Exception {
+    DFSZKFailoverController zkfc = DFSZKFailoverController.create(
+        conf);
+
+    assertEquals("Bind address not expected to be wildcard by default.",
+        zkfc.getRpcAddressToBindTo().getHostString(),
+        LOCALHOST_SERVER_ADDRESS);
+  }
+
+  @Test(timeout=30000)
+  public void testWithBindAddressSet() throws Exception {
+    conf.set(DFS_NAMENODE_SERVICE_RPC_BIND_HOST_KEY, WILDCARD_ADDRESS);
+    DFSZKFailoverController zkfc = DFSZKFailoverController.create(
+        conf);
+    String addr = zkfc.getRpcAddressToBindTo().getHostString();
+
+    assertEquals("Bind address " + addr + " is not wildcard.",
+        addr, WILDCARD_ADDRESS);
+  }
+
   /**
    * Tests that a Namenode in Observer state rejects any state transition
    * request from ZKFC, as a result of namenode's participation in the ZK