Merged r1235951 from branch-1 for HADOOP-7987.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.0@1235955 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -8,6 +8,8 @@ Release 1.0.1 - unreleased
 
     MAPREDUCE-3607. Port missing new API mapreduce lib classes to 1.x. (tomwhite)
 
+    HADOOP-7987. Support setting the run-as user in unsecure mode. (jitendra)
+
   BUG FIXES
 
     HADOOP-7964. Deadlock in NetUtils and SecurityUtil class initialization.

src/core/org/apache/hadoop/security/UserGroupInformation.java

@@ -71,6 +71,7 @@ public class UserGroupInformation {
    * Percentage of the ticket window to use before we renew ticket.
    */
   private static final float TICKET_RENEW_WINDOW = 0.80f;
+  static final String HADOOP_USER_NAME = "HADOOP_USER_NAME";
   
   /**
    * A login module that looks at the Kerberos, Unix, or Windows principal and
@@ -111,7 +112,16 @@ public class UserGroupInformation {
           LOG.debug("using kerberos user:"+user);
         }
       }
-      // if we don't have a kerberos user, use the OS user
+      //If we don't have a kerberos user and security is disabled, check
+      //if user is specified in the environment or properties
+      if (!isSecurityEnabled() && (user == null)) {
+        String envUser = System.getenv(HADOOP_USER_NAME);
+        if (envUser == null) {
+          envUser = System.getProperty(HADOOP_USER_NAME);
+        }
+        user = envUser == null ? null : new User(envUser);
+      }
+      // use the OS user
       if (user == null) {
         user = getCanonicalUser(OS_PRINCIPAL_CLASS);
         if (LOG.isDebugEnabled()) {

src/test/org/apache/hadoop/security/TestUserFromEnv.java

@@ -0,0 +1,32 @@
+/**
+ * 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.security;
+
+import java.io.IOException;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestUserFromEnv {
+
+  @Test
+  public void testUserFromEnvironment() throws IOException {
+    System.setProperty(UserGroupInformation.HADOOP_USER_NAME, "randomUser");
+    Assert.assertEquals("randomUser", UserGroupInformation.getLoginUser()
+        .getUserName());
+  }
+}