HDFS-13408. MiniDFSCluster to support being built on randomized base directory. Contributed by Xiao Liang

(cherry picked from commit f411de6a79a0a87f03c09366cfe7a7d0726ed932)
(cherry picked from commit cf272c5179a9cb4b524016c0fca7c69c9eaa92f1)
(cherry picked from commit 956ab12ede390e1eea0a66752e0e6711f47b4b94)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/MiniDFSCluster.java

@@ -198,8 +198,28 @@ public class MiniDFSCluster implements AutoCloseable {
       this.conf = conf;
       this.storagesPerDatanode =
           FsDatasetTestUtils.Factory.getFactory(conf).getDefaultNumOfDataDirs();
+      if (null == conf.get(HDFS_MINIDFS_BASEDIR)) {
+        conf.set(HDFS_MINIDFS_BASEDIR,
+            new File(getBaseDirectory()).getAbsolutePath());
+      }
     }
-    
+
+    public Builder(Configuration conf, File basedir) {
+      this.conf = conf;
+      this.storagesPerDatanode =
+          FsDatasetTestUtils.Factory.getFactory(conf).getDefaultNumOfDataDirs();
+      if (null == basedir) {
+        throw new IllegalArgumentException(
+            "MiniDFSCluster base directory cannot be null");
+      }
+      String cdir = conf.get(HDFS_MINIDFS_BASEDIR);
+      if (cdir != null) {
+        throw new IllegalArgumentException(
+            "MiniDFSCluster base directory already defined (" + cdir + ")");
+      }
+      conf.set(HDFS_MINIDFS_BASEDIR, basedir.getAbsolutePath());
+    }
+
     /**
      * Default: 0
      */

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestMiniDFSCluster.java

@@ -200,9 +200,8 @@ public class TestMiniDFSCluster {
   public void testIsClusterUpAfterShutdown() throws Throwable {
     Configuration conf = new HdfsConfiguration();
     File testDataCluster4 = new File(testDataPath, CLUSTER_4);
-    String c4Path = testDataCluster4.getAbsolutePath();
-    conf.set(MiniDFSCluster.HDFS_MINIDFS_BASEDIR, c4Path);
-    MiniDFSCluster cluster4 = new MiniDFSCluster.Builder(conf).build();
+    MiniDFSCluster cluster4 =
+        new MiniDFSCluster.Builder(conf, testDataCluster4).build();
     try {
       DistributedFileSystem dfs = cluster4.getFileSystem();
       dfs.setSafeMode(HdfsConstants.SafeModeAction.SAFEMODE_ENTER);
@@ -221,12 +220,11 @@ public class TestMiniDFSCluster {
     Configuration conf = new HdfsConfiguration();
     conf.set(DFSConfigKeys.DFS_DATANODE_HOST_NAME_KEY, "MYHOST");
     File testDataCluster5 = new File(testDataPath, CLUSTER_5);
-    String c5Path = testDataCluster5.getAbsolutePath();
-    conf.set(MiniDFSCluster.HDFS_MINIDFS_BASEDIR, c5Path);
-    try (MiniDFSCluster cluster5 = new MiniDFSCluster.Builder(conf)
-        .numDataNodes(1)
-        .checkDataNodeHostConfig(true)
-        .build()) {
+    try (MiniDFSCluster cluster5 =
+        new MiniDFSCluster.Builder(conf, testDataCluster5)
+          .numDataNodes(1)
+          .checkDataNodeHostConfig(true)
+          .build()) {
       assertEquals("DataNode hostname config not respected", "MYHOST",
           cluster5.getDataNodes().get(0).getDatanodeId().getHostName());
     }