Amend HDFS-2841 to include new file which was omitted from original commit.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-1623@1237971 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -0,0 +1,59 @@
+/**
+ * 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.tools;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.CommonConfigurationKeys;
+import org.apache.hadoop.ha.HAAdmin;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.util.ToolRunner;
+
+/**
+ * Class to extend HAAdmin to do a little bit of HDFS-specific configuration.
+ */
+public class DFSHAAdmin extends HAAdmin {
+  
+  private static final Log LOG = 
+    LogFactory.getLog(DFSHAAdmin.class);
+  
+  @Override
+  public void setConf(Configuration conf) {
+    if (conf != null) {
+      // Make a copy so we don't mutate it. Also use an HdfsConfiguration to
+      // force loading of hdfs-site.xml.
+      conf = new HdfsConfiguration(conf);
+      String nameNodePrincipal = conf.get(
+          DFSConfigKeys.DFS_NAMENODE_USER_NAME_KEY, "");
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("Using NN principal: " + nameNodePrincipal);
+      }
+
+      conf.set(CommonConfigurationKeys.HADOOP_SECURITY_SERVICE_USER_NAME_KEY,
+          nameNodePrincipal);
+    }
+    super.setConf(conf);
+  }
+
+  public static void main(String[] argv) throws Exception {
+    int res = ToolRunner.run(new DFSHAAdmin(), argv);
+    System.exit(res);
+  }
+}