HADOOP-18427. Improve ZKDelegationTokenSecretManager#startThead With recommended methods. (apache#4812)

Author: slfan1989

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/delegation/ZKDelegationTokenSecretManager.java

@@ -43,7 +43,6 @@
 import org.apache.curator.framework.recipes.shared.SharedCount;
 import org.apache.curator.framework.recipes.shared.VersionedValue;
 import org.apache.curator.retry.RetryNTimes;
-import org.apache.curator.utils.EnsurePath;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceAudience.Private;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
@@ -135,6 +134,11 @@ public static void setCurator(CuratorFramework curator) {
     CURATOR_TL.set(curator);
   }
 
+  @VisibleForTesting
+  protected static CuratorFramework getCurator() {
+    return CURATOR_TL.get();
+  }
+
   private final boolean isExternalClient;
   protected final CuratorFramework zkClient;
   private SharedCount delTokSeqCounter;
@@ -261,9 +265,8 @@ public void startThreads() throws IOException {
       // If namespace parents are implicitly created, they won't have ACLs.
       // So, let's explicitly create them.
       CuratorFramework nullNsFw = zkClient.usingNamespace(null);
-      EnsurePath ensureNs = nullNsFw.newNamespaceAwareEnsurePath("/" + zkClient.getNamespace());
       try {
-        ensureNs.ensure(nullNsFw.getZookeeperClient());
+        nullNsFw.create().creatingParentContainersIfNeeded().forPath("/" + zkClient.getNamespace());
       } catch (Exception e) {
         throw new IOException("Could not create namespace", e);
       }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/security/token/delegation/TestZKDelegationTokenSecretManager.java

@@ -40,6 +40,7 @@
 import org.apache.zookeeper.ZooDefs;
 import org.apache.zookeeper.data.ACL;
 import org.apache.zookeeper.data.Id;
+import org.apache.zookeeper.data.Stat;
 import org.apache.zookeeper.server.auth.DigestAuthenticationProvider;
 import org.junit.After;
 import org.junit.Assert;
@@ -506,4 +507,32 @@ public Boolean get() {
       }
     }, 1000, 5000);
   }
+
+  @Test
+  public void testCreatingParentContainersIfNeeded() throws Exception {
+
+    String connectString = zkServer.getConnectString();
+    RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
+    Configuration conf = getSecretConf(connectString);
+    CuratorFramework curatorFramework =
+        CuratorFrameworkFactory.builder()
+        .connectString(connectString)
+        .retryPolicy(retryPolicy)
+        .build();
+    curatorFramework.start();
+    ZKDelegationTokenSecretManager.setCurator(curatorFramework);
+    DelegationTokenManager tm1 = new DelegationTokenManager(conf, new Text("foo"));
+
+    // When the init method is called,
+    // the ZKDelegationTokenSecretManager#startThread method will be called,
+    // and the creatingParentContainersIfNeeded will be called to create the nameSpace.
+    tm1.init();
+
+    String workingPath = "/" + conf.get(ZKDelegationTokenSecretManager.ZK_DTSM_ZNODE_WORKING_PATH,
+        ZKDelegationTokenSecretManager.ZK_DTSM_ZNODE_WORKING_PATH_DEAFULT) + "/ZKDTSMRoot";
+
+    // Check if the created NameSpace exists.
+    Stat stat = curatorFramework.checkExists().forPath(workingPath);
+    Assert.assertNotNull(stat);
+  }
 }