HDFS-14006. Refactor name node to allow different token verification implementations. Contributed by CR Hota.

(cherry picked from commit 00d5e631b5)
(cherry picked from commit eca7bc7ac4)

 Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/JspHelper.java

@@ -23,7 +23,6 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
-import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeHttpServer;
 import org.apache.hadoop.hdfs.web.resources.DelegationParam;
 import org.apache.hadoop.hdfs.web.resources.DoAsParam;
@@ -176,10 +175,11 @@ public class JspHelper {
     DelegationTokenIdentifier id = new DelegationTokenIdentifier();
     id.readFields(in);
     if (context != null) {
-      final NameNode nn = NameNodeHttpServer.getNameNodeFromContext(context);
-      if (nn != null) {
+      final TokenVerifier<DelegationTokenIdentifier> tokenVerifier =
+          NameNodeHttpServer.getTokenVerifierFromContext(context);
+      if (tokenVerifier != null) {
         // Verify the token.
-        nn.getNamesystem().verifyToken(id, token.getPassword());
+        tokenVerifier.verifyToken(id, token.getPassword());
       }
     }
     UserGroupInformation ugi = id.getUser();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/TokenVerifier.java

@@ -0,0 +1,35 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF 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.apache.hadoop.hdfs.server.common;
+
+import java.io.IOException;
+import org.apache.hadoop.security.token.delegation.AbstractDelegationTokenIdentifier;
+
+/**
+ * Interface to verify delegation tokens passed through WebHDFS.
+ * Implementations are intercepted by JspHelper that pass delegation token
+ * for verification.
+ */
+public interface TokenVerifier<T extends AbstractDelegationTokenIdentifier> {
+
+  /* Verify delegation token passed through WebHDFS
+   * Name node, Router implement this for JspHelper to verify token
+   */
+  void verifyToken(T t, byte[] password) throws IOException;
+
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java

@@ -46,6 +46,7 @@ import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.protocol.ClientProtocol;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
 import org.apache.hadoop.hdfs.server.aliasmap.InMemoryAliasMap;
 import org.apache.hadoop.hdfs.server.aliasmap.InMemoryLevelDBAliasMapServer;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
@@ -55,6 +56,7 @@ import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.RollingUpgradeSt
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
 import org.apache.hadoop.hdfs.server.common.MetricsLoggerTask;
 import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
+import org.apache.hadoop.hdfs.server.common.TokenVerifier;
 import org.apache.hadoop.hdfs.server.namenode.ha.ActiveState;
 import org.apache.hadoop.hdfs.server.namenode.ha.BootstrapStandby;
 import org.apache.hadoop.hdfs.server.namenode.ha.HAContext;
@@ -214,7 +216,7 @@ import static org.apache.hadoop.fs.CommonConfigurationKeys.IPC_BACKOFF_ENABLE_DE
  **********************************************************/
 @InterfaceAudience.Private
 public class NameNode extends ReconfigurableBase implements
-    NameNodeStatusMXBean {
+    NameNodeStatusMXBean, TokenVerifier<DelegationTokenIdentifier> {
   static{
     HdfsConfiguration.init();
   }
@@ -670,6 +672,11 @@ public class NameNode extends ReconfigurableBase implements
     return (ugi != null) ? ugi : UserGroupInformation.getCurrentUser();
   }
 
+  @Override
+  public void verifyToken(DelegationTokenIdentifier id, byte[] password)
+      throws IOException {
+    namesystem.verifyToken(id, password);
+  }
 
   /**
    * Login as the configured user for the NameNode.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeHttpServer.java

@@ -37,6 +37,7 @@ import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.server.common.JspHelper;
+import org.apache.hadoop.hdfs.server.common.TokenVerifier;
 import org.apache.hadoop.hdfs.server.namenode.startupprogress.StartupProgress;
 import org.apache.hadoop.hdfs.server.namenode.web.resources.NamenodeWebHdfsMethods;
 import org.apache.hadoop.hdfs.web.AuthFilter;
@@ -308,6 +309,11 @@ public class NameNodeHttpServer {
     return (NameNode)context.getAttribute(NAMENODE_ATTRIBUTE_KEY);
   }
 
+  public static TokenVerifier
+      getTokenVerifierFromContext(ServletContext context) {
+    return (TokenVerifier) context.getAttribute(NAMENODE_ATTRIBUTE_KEY);
+  }
+
   static Configuration getConfFromContext(ServletContext context) {
     return (Configuration)context.getAttribute(JspHelper.CURRENT_CONF);
   }