HDDS-417. Ambiguous error message when using genconf tool. Contributed by Dinesh Chitlangia.

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/genconf/TestGenerateOzoneRequiredConfigurations.java

@@ -95,8 +95,8 @@ public class TestGenerateOzoneRequiredConfigurations {
     try (PrintStream ps = new PrintStream(outContent)) {
       System.setOut(ps);
       GenerateOzoneRequiredConfigurations.main(args);
-      Assert.assertThat(outContent.toString(),
-              CoreMatchers.containsString("ozone-site.xml has been generated at"));
+      Assert.assertThat(outContent.toString(), CoreMatchers.containsString(
+          "ozone-site.xml has been generated at"));
       System.setOut(oldStream);
     }
   }
@@ -123,8 +123,29 @@ public class TestGenerateOzoneRequiredConfigurations {
     tempPath.setWritable(true);
   }
 
+  /**
+   * Test to avoid generating ozone-site.xml when invalid permission.
+   * @throws Exception
+   */
+  @Test
+  public void generateConfigurationsFailureForInvalidPath() throws Exception {
+    File tempPath = getRandomTempDir();
+    tempPath.setReadOnly();
+    String[] args = new String[]{"-output",
+        tempPath.getAbsolutePath() + "/ozone-site.xml"};
+    GenerateOzoneRequiredConfigurations.main(args);
+
+    Assert.assertEquals("Path is invalid", false,
+        GenerateOzoneRequiredConfigurations.isValidPath(args[1]));
+
+    Assert.assertEquals("Config file not generated", 1,
+        GenerateOzoneRequiredConfigurations.generateConfigurations(args[1]));
+    tempPath.setWritable(true);
+  }
+
   private File getRandomTempDir() throws IOException {
-    File tempDir = new File(outputBaseDir, RandomStringUtils.randomAlphanumeric(5));
+    File tempDir = new File(outputBaseDir,
+        RandomStringUtils.randomAlphanumeric(5));
     FileUtils.forceMkdir(tempDir);
     return tempDir;
   }

hadoop-ozone/tools/src/main/java/org/apache/hadoop/ozone/genconf/GenerateOzoneRequiredConfigurations.java

@@ -25,6 +25,7 @@ import javax.xml.bind.JAXBException;
 import javax.xml.bind.Marshaller;
 import java.io.File;
 import java.net.URL;
+import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
 import java.nio.file.Paths;
 import java.util.ArrayList;
@@ -94,18 +95,17 @@ public final class GenerateOzoneRequiredConfigurations {
   }
 
   /**
-   * Check if the path is valid.
+   * Check if the path is valid directory.
    *
    * @param path
-   * @return true, if path is valid, else return false
+   * @return true, if path is valid directory, else return false
    */
   public static boolean isValidPath(String path) {
     try {
-      Paths.get(path);
+      return Files.isDirectory(Paths.get(path));
     } catch (InvalidPathException | NullPointerException ex) {
       return false;
     }
-    return true;
   }
 
   /**
@@ -129,12 +129,12 @@ public final class GenerateOzoneRequiredConfigurations {
   public static int generateConfigurations(String path) throws JAXBException {
 
     if (!isValidPath(path)) {
-      System.out.println("Invalid path or insufficient permission");
+      System.out.println("Invalid directory path.");
       return FAILURE;
     }
 
     if (!canWrite(path)) {
-      System.out.println("Invalid path or insufficient permission");
+      System.out.println("Insufficient permission.");
       return FAILURE;
     }