HADOOP-12468. Partial group resolution failure should not result in user lockout. (Wei-Chiu Chuang via Yongjun Zhang)

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -1377,6 +1377,9 @@ Release 2.8.0 - UNRELEASED
     HADOOP-12598. Add XML namespace declarations for some hadoop/tools modules.
     (Xin Wang via aajisaka)
 
+    HADOOP-12468. Partial group resolution failure should not result in user
+    lockout. (Wei-Chiu Chuang via Yongjun Zhang)
+
   OPTIMIZATIONS
 
     HADOOP-12051. ProtobufRpcEngine.invoke() should use Exception.toString()

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/ShellBasedUnixGroupsMapping.java

@@ -21,12 +21,14 @@
 import java.util.LinkedList;
 import java.util.List;
 import java.util.StringTokenizer;
+import org.apache.commons.lang.StringUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.util.Shell;
 import org.apache.hadoop.util.Shell.ExitCodeException;
+import org.apache.hadoop.util.Shell.ShellCommandExecutor;
 
 /**
  * A simple shell-based implementation of {@link GroupMappingServiceProvider} 
@@ -41,15 +43,33 @@ public class ShellBasedUnixGroupsMapping
   private static final Log LOG =
     LogFactory.getLog(ShellBasedUnixGroupsMapping.class);
 
+  @SuppressWarnings("serial")
+  private static class PartialGroupNameException extends IOException {
+    public PartialGroupNameException(String message) {
+      super(message);
+    }
+
+    public PartialGroupNameException(String message, Throwable err) {
+      super(message, err);
+    }
+
+    @Override
+    public String toString() {
+      final StringBuilder sb =
+          new StringBuilder("PartialGroupNameException ");
+      sb.append(super.getMessage());
+      return sb.toString();
+    }
+  }
   /**
    * Returns list of groups for a user
    *
-   * @param user get groups for this user
+   * @param userName get groups for this user
    * @return list of groups for a given user
    */
   @Override
-  public List<String> getGroups(String user) throws IOException {
-    return getUnixGroups(user);
+  public List<String> getGroups(String userName) throws IOException {
+    return getUnixGroups(userName);
   }
 
   /**
@@ -70,30 +90,52 @@ public void cacheGroupsAdd(List<String> groups) throws IOException {
     // does nothing in this provider of user to groups mapping
   }
 
+  /**
+   * Create a ShellCommandExecutor object using the user's name.
+   *
+   * @param userName user's name
+   * @return a ShellCommandExecutor object
+   */
+  protected ShellCommandExecutor createGroupExecutor(String userName) {
+    return new ShellCommandExecutor(
+        Shell.getGroupsForUserCommand(userName), null, null, 0L);
+  }
+
+  /**
+   * Create a ShellCommandExecutor object for fetch a user's group id list.
+   *
+   * @param userName the user's name
+   * @return a ShellCommandExecutor object
+   */
+  protected ShellCommandExecutor createGroupIDExecutor(String userName) {
+    return new ShellCommandExecutor(
+        Shell.getGroupsIDForUserCommand(userName), null, null, 0L);
+  }
+
   /**
    * Get the current user's group list from Unix by running the command 'groups'
-   * NOTE. For non-existing user it will return EMPTY list
-   * @param user user name
+   * NOTE. For non-existing user it will return EMPTY list.
+   *
+   * @param user get groups for this user
    * @return the groups list that the <code>user</code> belongs to. The primary
    *         group is returned first.
    * @throws IOException if encounter any error when running the command
    */
-  private static List<String> getUnixGroups(final String user) throws IOException {
-    String result = "";
-    try {
-      result = Shell.execCommand(Shell.getGroupsForUserCommand(user));
-    } catch (ExitCodeException e) {
-      // if we didn't get the group - just return empty list;
-      LOG.warn("got exception trying to get groups for user " + user + ": "
-          + e.getMessage());
-      return new LinkedList<String>();
-    }
+  private List<String> getUnixGroups(String user) throws IOException {
+    ShellCommandExecutor executor = createGroupExecutor(user);
 
-    StringTokenizer tokenizer =
-        new StringTokenizer(result, Shell.TOKEN_SEPARATOR_REGEX);
-    List<String> groups = new LinkedList<String>();
-    while (tokenizer.hasMoreTokens()) {
-      groups.add(tokenizer.nextToken());
+    List<String> groups;
+    try {
+      executor.execute();
+      groups = resolveFullGroupNames(executor.getOutput());
+    } catch (ExitCodeException e) {
+      try {
+        groups = resolvePartialGroupNames(user, e.getMessage(),
+            executor.getOutput());
+      } catch (PartialGroupNameException pge) {
+        LOG.warn("unable to return groups for user " + user, pge);
+        return new LinkedList<>();
+      }
     }
 
     // remove duplicated primary group
@@ -108,4 +150,101 @@ private static List<String> getUnixGroups(final String user) throws IOException
 
     return groups;
   }
+
+  /**
+   * Attempt to parse group names given that some names are not resolvable.
+   * Use the group id list to identify those that are not resolved.
+   *
+   * @param groupNames a string representing a list of group names
+   * @param groupIDs a string representing a list of group ids
+   * @return a linked list of group names
+   * @throws PartialGroupNameException
+   */
+  private List<String> parsePartialGroupNames(String groupNames,
+      String groupIDs) throws PartialGroupNameException {
+    StringTokenizer nameTokenizer =
+        new StringTokenizer(groupNames, Shell.TOKEN_SEPARATOR_REGEX);
+    StringTokenizer idTokenizer =
+        new StringTokenizer(groupIDs, Shell.TOKEN_SEPARATOR_REGEX);
+    List<String> groups = new LinkedList<String>();
+    while (nameTokenizer.hasMoreTokens()) {
+      // check for unresolvable group names.
+      if (!idTokenizer.hasMoreTokens()) {
+        throw new PartialGroupNameException("Number of group names and ids do"
+        + " not match. group name =" + groupNames + ", group id = " + groupIDs);
+      }
+      String groupName = nameTokenizer.nextToken();
+      String groupID = idTokenizer.nextToken();
+      if (!StringUtils.isNumeric(groupName) ||
+          !groupName.equals(groupID)) {
+        // if the group name is non-numeric, it is resolved.
+        // if the group name is numeric, but is not the same as group id,
+        // regard it as a group name.
+        // if unfortunately, some group names are not resolvable, and
+        // the group name is the same as the group id, regard it as not
+        // resolved.
+        groups.add(groupName);
+      }
+    }
+    return groups;
+  }
+
+  /**
+   * Attempt to partially resolve group names.
+   *
+   * @param userName the user's name
+   * @param errMessage error message from the shell command
+   * @param groupNames the incomplete list of group names
+   * @return a list of resolved group names
+   * @throws PartialGroupNameException
+   */
+  private List<String> resolvePartialGroupNames(String userName,
+      String errMessage, String groupNames) throws PartialGroupNameException {
+    // Exception may indicate that some group names are not resolvable.
+    // Shell-based implementation should tolerate unresolvable groups names,
+    // and return resolvable ones, similar to what JNI-based implementation
+    // does.
+    if (Shell.WINDOWS) {
+      throw new PartialGroupNameException("Does not support partial group"
+      + " name resolution on Windows. " + errMessage);
+    }
+    if (groupNames.isEmpty()) {
+      throw new PartialGroupNameException("The user name '" + userName
+          + "' is not found. " + errMessage);
+    } else {
+      LOG.warn("Some group names for '" + userName + "' are not resolvable. "
+          + errMessage);
+      // attempt to partially resolve group names
+      try {
+        ShellCommandExecutor exec2 = createGroupIDExecutor(userName);
+        exec2.execute();
+        return parsePartialGroupNames(groupNames, exec2.getOutput());
+      } catch (ExitCodeException ece) {
+        // If exception is thrown trying to get group id list,
+        // something is terribly wrong, so give up.
+        throw new PartialGroupNameException("failed to get group id list for " +
+        "user '" + userName + "'", ece);
+      } catch (IOException ioe) {
+        throw new PartialGroupNameException("can't execute the shell command to"
+        + " get the list of group id for user '" + userName + "'", ioe);
+      }
+    }
+  }
+
+  /**
+   * Split group names into a linked list.
+   *
+   * @param groupNames a string representing the user's group names
+   * @return a linked list of group names
+   */
+  private List<String> resolveFullGroupNames(String groupNames) {
+    StringTokenizer tokenizer =
+        new StringTokenizer(groupNames, Shell.TOKEN_SEPARATOR_REGEX);
+    List<String> groups = new LinkedList<String>();
+    while (tokenizer.hasMoreTokens()) {
+      groups.add(tokenizer.nextToken());
+    }
+
+    return groups;
+  }
 }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Shell.java

@@ -185,8 +185,23 @@ public static String[] getGroupsForUserCommand(final String user) {
     //'groups username' command return is inconsistent across different unixes
     return WINDOWS ?
       new String[]
-          { getWinUtilsPath(), "groups", "-F", "\"" + user + "\"" }
-      : new String [] {"bash", "-c", "id -gn " + user + "&& id -Gn " + user};
+          {getWinUtilsPath(), "groups", "-F", "\"" + user + "\""}
+      : new String[] {"bash", "-c", "id -gn " + user + "; id -Gn " + user};
+  }
+
+  /**
+   * A command to get a given user's group id list.
+   * The command will get the user's primary group
+   * first and finally get the groups list which includes the primary group.
+   * i.e. the user's primary group will be included twice.
+   * This command does not support Windows and will only return group names.
+   */
+  public static String[] getGroupsIDForUserCommand(final String user) {
+    //'groups username' command return is inconsistent across different unixes
+    return WINDOWS ?
+        new String[]
+            {getWinUtilsPath(), "groups", "-F", "\"" + user + "\""}
+        : new String[] {"bash", "-c", "id -g " + user + "; id -G " + user};
   }
 
   /** A command to get a given netgroup's user list. */

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/security/TestShellBasedUnixGroupsMapping.java

@@ -0,0 +1,213 @@
+/**
+ * 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 java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.util.Shell.ExitCodeException;
+import org.apache.hadoop.util.Shell.ShellCommandExecutor;
+import org.junit.Test;
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class TestShellBasedUnixGroupsMapping {
+  private static final Log LOG =
+      LogFactory.getLog(TestShellBasedUnixGroupsMapping.class);
+
+  private class TestGroupUserNotExist
+      extends ShellBasedUnixGroupsMapping {
+    /**
+     * Create a ShellCommandExecutor object which returns exit code 1,
+     * emulating the case that the user does not exist.
+     *
+     * @param userName not used
+     * @return a mock ShellCommandExecutor object
+     */
+    @Override
+    protected ShellCommandExecutor createGroupExecutor(String userName) {
+      ShellCommandExecutor executor = mock(ShellCommandExecutor.class);
+
+      try {
+        doThrow(new ExitCodeException(1,
+            "id: foobarusernotexist: No such user")).
+            when(executor).execute();
+
+        when(executor.getOutput()).thenReturn("");
+      } catch (IOException e) {
+        LOG.warn(e.getMessage());
+      }
+      return executor;
+    }
+  }
+
+  @Test
+  public void testGetGroupsNonexistentUser() throws Exception {
+    TestGroupUserNotExist mapping = new TestGroupUserNotExist();
+
+    List<String> groups = mapping.getGroups("foobarusernotexist");
+    assertTrue(groups.isEmpty());
+  }
+
+  private class TestGroupNotResolvable
+      extends ShellBasedUnixGroupsMapping {
+    /**
+     * Create a ShellCommandExecutor object which returns partially resolved
+     * group names for a user.
+     *
+     * @param userName not used
+     * @return a mock ShellCommandExecutor object
+     */
+    @Override
+    protected ShellCommandExecutor createGroupExecutor(String userName) {
+      ShellCommandExecutor executor = mock(ShellCommandExecutor.class);
+
+      try {
+        // There is both a group name 9999 and a group ID 9999.
+        // This is treated as unresolvable group.
+        doThrow(new ExitCodeException(1, "cannot find name for group ID 9999")).
+            when(executor).execute();
+
+        when(executor.getOutput()).thenReturn("9999\n9999 abc def");
+      } catch (IOException e) {
+        LOG.warn(e.getMessage());
+      }
+      return executor;
+    }
+
+    @Override
+    protected ShellCommandExecutor createGroupIDExecutor(String userName) {
+      ShellCommandExecutor executor = mock(ShellCommandExecutor.class);
+
+      when(executor.getOutput()).thenReturn("9999\n9999 1 2");
+      return executor;
+    }
+  }
+
+  @Test
+  public void testGetGroupsNotResolvable() throws Exception {
+    TestGroupNotResolvable mapping = new TestGroupNotResolvable();
+
+    List<String> groups = mapping.getGroups("user");
+    assertTrue(groups.size() == 2);
+    assertTrue(groups.contains("abc"));
+    assertTrue(groups.contains("def"));
+  }
+
+  private class TestNumericGroupResolvable
+      extends ShellBasedUnixGroupsMapping {
+    /**
+     * Create a ShellCommandExecutor object which returns numerical group
+     * names of a user.
+     *
+     * @param userName not used
+     * @return a mock ShellCommandExecutor object
+     */
+    @Override
+    protected ShellCommandExecutor createGroupExecutor(String userName) {
+      ShellCommandExecutor executor = mock(ShellCommandExecutor.class);
+
+      try {
+        // There is a numerical group 23, but no group name 23.
+        // Thus 23 is treated as a resolvable group name.
+        doNothing().when(executor).execute();
+        when(executor.getOutput()).thenReturn("23\n23 groupname zzz");
+      } catch (IOException e) {
+        LOG.warn(e.getMessage());
+      }
+      return executor;
+    }
+
+    @Override
+    protected ShellCommandExecutor createGroupIDExecutor(String userName) {
+      ShellCommandExecutor executor = mock(ShellCommandExecutor.class);
+
+      try {
+        doNothing().when(executor).execute();
+        when(executor.getOutput()).thenReturn("111\n111 112 113");
+      } catch (IOException e) {
+        LOG.warn(e.getMessage());
+      }
+      return executor;
+    }
+  }
+
+  @Test
+  public void testGetNumericGroupsResolvable() throws Exception {
+    TestNumericGroupResolvable mapping = new TestNumericGroupResolvable();
+
+    List<String> groups = mapping.getGroups("user");
+    assertTrue(groups.size() == 3);
+    assertTrue(groups.contains("23"));
+    assertTrue(groups.contains("groupname"));
+    assertTrue(groups.contains("zzz"));
+  }
+
+  private class TestGroupResolvable
+      extends ShellBasedUnixGroupsMapping {
+    /**
+     * Create a ShellCommandExecutor object to return the group names of a user.
+     *
+     * @param userName not used
+     * @return a mock ShellCommandExecutor object
+     */
+    @Override
+    protected ShellCommandExecutor createGroupExecutor(String userName) {
+      ShellCommandExecutor executor = mock(ShellCommandExecutor.class);
+
+      try {
+        doNothing().when(executor).execute();
+        when(executor.getOutput()).thenReturn("abc\ndef abc hij");
+      } catch (IOException e) {
+        LOG.warn(e.getMessage());
+      }
+      return executor;
+    }
+
+    @Override
+    protected ShellCommandExecutor createGroupIDExecutor(String userName) {
+      ShellCommandExecutor executor = mock(ShellCommandExecutor.class);
+
+      try {
+        doNothing().when(executor).execute();
+        when(executor.getOutput()).thenReturn("1\n1 2 3");
+      } catch (IOException e) {
+        LOG.warn(e.getMessage());
+      }
+      return executor;
+    }
+  }
+
+  @Test
+  public void testGetGroupsResolvable() throws Exception {
+    TestGroupResolvable mapping = new TestGroupResolvable();
+
+    List<String> groups = mapping.getGroups("user");
+    assertTrue(groups.size() == 3);
+    assertTrue(groups.contains("abc"));
+    assertTrue(groups.contains("def"));
+    assertTrue(groups.contains("hij"));
+  }
+}
+
+