SOLR-9441: Solr collection backup on HDFS can only be manipulated by the Solr process owner.

This closes #71.

solr/CHANGES.txt

@@ -211,6 +211,9 @@ Bug Fixes
 * SOLR-9687: Fixed Interval Facet count issue in cases of open/close intervals on the same values
  (Andy Chillrud, Tomás Fernández Löbbe)  
 
+* SOLR-9441: Solr collection backup on HDFS can only be manipulated by the Solr process owner. 
+ (Hrishikesh Gadre via Mark Miller)
+
 Optimizations
 ----------------------
 

solr/core/src/java/org/apache/solr/core/backup/repository/HdfsBackupRepository.java

@@ -26,6 +26,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
@@ -41,6 +42,8 @@ import org.apache.solr.store.hdfs.HdfsDirectory.HdfsIndexInput;
 import com.google.common.base.Preconditions;
 
 public class HdfsBackupRepository implements BackupRepository {
+  private static final String HDFS_UMASK_MODE_PARAM = "solr.hdfs.permissions.umask-mode";
+
   private HdfsDirectoryFactory factory;
   private Configuration hdfsConfig = null;
   private FileSystem fileSystem = null;
@@ -58,6 +61,12 @@ public class HdfsBackupRepository implements BackupRepository {
     factory.init(args);
     this.hdfsConfig = factory.getConf();
 
+    // Configure the umask mode if specified.
+    if (args.get(HDFS_UMASK_MODE_PARAM) != null) {
+      String umaskVal = (String)args.get(HDFS_UMASK_MODE_PARAM);
+      this.hdfsConfig.set(FsPermission.UMASK_LABEL, umaskVal);
+    }
+
     String hdfsSolrHome = (String) Preconditions.checkNotNull(args.get(HdfsDirectoryFactory.HDFS_HOME),
         "Please specify " + HdfsDirectoryFactory.HDFS_HOME + " property.");
     Path path = new Path(hdfsSolrHome);

solr/core/src/test/org/apache/solr/handler/TestHdfsBackupRestoreCore.java

@@ -27,7 +27,10 @@ import java.util.Map;
 import com.carrotsearch.randomizedtesting.annotations.ThreadLeakFilters;
 import org.apache.commons.io.IOUtils;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.permission.FsAction;
+import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.DistributedFileSystem;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
@@ -88,6 +91,7 @@ public class TestHdfsBackupRestoreCore extends SolrCloudTestCase {
       "      <str name=\"location\">${solr.hdfs.default.backup.path}</str>\n" +
       "      <str name=\"solr.hdfs.home\">${solr.hdfs.home:}</str>\n" +
       "      <str name=\"solr.hdfs.confdir\">${solr.hdfs.confdir:}</str>\n" +
+      "      <str name=\"solr.hdfs.permissions.umask-mode\">${solr.hdfs.permissions.umask-mode:000}</str>\n" +
       "    </repository>\n" +
       "  </backup>\n" +
       "  \n" +
@@ -233,6 +237,13 @@ public class TestHdfsBackupRestoreCore extends SolrCloudTestCase {
         }
         //See if restore was successful by checking if all the docs are present again
         BackupRestoreUtils.verifyDocs(nDocs, masterClient, coreName);
+
+        // Verify the permissions for the backup folder.
+        FileStatus status = fs.getFileStatus(new org.apache.hadoop.fs.Path("/backup/snapshot."+backupName));
+        FsPermission perm = status.getPermission();
+        assertEquals(FsAction.ALL, perm.getUserAction());
+        assertEquals(FsAction.ALL, perm.getGroupAction());
+        assertEquals(FsAction.ALL, perm.getOtherAction());
       }
     }
   }