From 39c0909e3e7e04792a2e6c648feba5664c49df54 Mon Sep 17 00:00:00 2001
From: Gary Helmling <garyh@apache.org>
Date: Sat, 1 Oct 2011 01:44:39 +0000
Subject: [PATCH] HBASE-4515  User.getCurrent() can fail to initialize the
 current user

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1177881 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                   |  1 +
 .../apache/hadoop/hbase/security/User.java    | 21 ++++++++++++++--
 .../hadoop/hbase/security/TestUser.java       | 24 +++++++++++++++++++
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 3d46e8ab80d..cc107775e14 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -682,6 +682,7 @@ Release 0.90.5 - Unreleased
                (Lars Hofhansl)
    HBASE-4295  rowcounter does not return the correct number of rows in
                certain circumstances (David Revell)
+   HBASE-4515  User.getCurrent() can fail to initialize the current user
 
   IMPROVEMENT
    HBASE-4205  Enhance HTable javadoc (Eric Charles)
diff --git a/src/main/java/org/apache/hadoop/hbase/security/User.java b/src/main/java/org/apache/hadoop/hbase/security/User.java
index d90f2c72211..00bd06d022e 100644
--- a/src/main/java/org/apache/hadoop/hbase/security/User.java
+++ b/src/main/java/org/apache/hadoop/hbase/security/User.java
@@ -22,6 +22,7 @@ package org.apache.hadoop.hbase.security;
 
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.util.Methods;
 import org.apache.hadoop.mapred.JobConf;
 import org.apache.hadoop.mapreduce.Job;
@@ -97,11 +98,16 @@ public abstract class User {
    * Returns the {@code User} instance within current execution context.
    */
   public static User getCurrent() throws IOException {
+    User user;
     if (IS_SECURE_HADOOP) {
-      return new SecureHadoopUser();
+      user = new SecureHadoopUser();
     } else {
-      return new HadoopUser();
+      user = new HadoopUser();
     }
+    if (user.ugi == null) {
+      return null;
+    }
+    return user;
   }
 
   /**
@@ -170,6 +176,17 @@ public abstract class User {
     private HadoopUser() {
       try {
         ugi = (UserGroupInformation) callStatic("getCurrentUGI");
+        if (ugi == null) {
+          // Secure Hadoop UGI will perform an implicit login if the current
+          // user is null.  Emulate the same behavior here for consistency
+          Configuration conf = HBaseConfiguration.create();
+          ugi = (UserGroupInformation) callStatic("login",
+              new Class[]{ Configuration.class }, new Object[]{ conf });
+          if (ugi != null) {
+            callStatic("setCurrentUser",
+                new Class[]{ UserGroupInformation.class }, new Object[]{ ugi });
+          }
+        }
       } catch (RuntimeException re) {
         throw re;
       } catch (Exception e) {
diff --git a/src/test/java/org/apache/hadoop/hbase/security/TestUser.java b/src/test/java/org/apache/hadoop/hbase/security/TestUser.java
index 6e497daf90e..cef900ec1c7 100644
--- a/src/test/java/org/apache/hadoop/hbase/security/TestUser.java
+++ b/src/test/java/org/apache/hadoop/hbase/security/TestUser.java
@@ -21,8 +21,12 @@ package org.apache.hadoop.hbase.security;
 
 import static org.junit.Assert.*;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.security.UnixUserGroupInformation;
+import org.apache.hadoop.security.UserGroupInformation;
 import org.junit.Test;
 
 import java.io.IOException;
@@ -30,6 +34,8 @@ import java.security.PrivilegedAction;
 import java.security.PrivilegedExceptionAction;
 
 public class TestUser {
+  private static Log LOG = LogFactory.getLog(TestUser.class);
+
   @Test
   public void testBasicAttributes() throws Exception {
     Configuration conf = HBaseConfiguration.create();
@@ -79,4 +85,22 @@ public class TestUser {
       }
     });
   }
+
+  /**
+   * Make sure that we're returning a result for the current user.
+   * Previously getCurrent() was returning null if not initialized on
+   * non-secure Hadoop variants.
+   */
+  @Test
+  public void testGetCurrent() throws Exception {
+    User user1 = User.getCurrent();
+    assertNotNull(user1.ugi);
+    LOG.debug("User1 is "+user1.getName());
+
+    for (int i =0 ; i< 100; i++) {
+      User u = User.getCurrent();
+      assertNotNull(u);
+      assertEquals(user1.getName(), u.getName());
+    }
+  }
 }