HDDS-455. Ozone genconf tool must use picocli. Contributed by Dinesh Chitlangia.

hadoop-ozone/docs/content/Settings.md

@@ -53,7 +53,7 @@ following command. This will generate a template called ```ozone-site.xml``` at
 the specified path (directory).
 
 {{< highlight bash >}}
-ozone genconf -output <path>
+ozone genconf <path>
 {{< /highlight >}}
 
 Let us look at the settings inside the generated file (ozone-site.xml)  and

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

@@ -18,7 +18,12 @@
 
 package org.apache.hadoop.ozone.genconf;
 
+import org.apache.hadoop.hdds.cli.GenericCli;
+import org.apache.hadoop.hdds.cli.HddsVersionProvider;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
+import picocli.CommandLine.Command;
+import picocli.CommandLine.Parameters;
+import picocli.CommandLine.PicocliException;
 
 import javax.xml.bind.JAXBContext;
 import javax.xml.bind.JAXBException;
@@ -30,112 +35,58 @@ import java.nio.file.InvalidPathException;
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
-
 /**
  * GenerateOzoneRequiredConfigurations - A tool to generate ozone-site.xml<br>
  * This tool generates an ozone-site.xml with minimally required configs.
  * This tool can be invoked as follows:<br>
  * <ul>
- * <li>ozone genconf -output <Path to output file></li>
- * <li>ozone genconf -help</li>
+ * <li>ozone genconf <Path to output file></li>
+ * <li>ozone genconf --help</li>
+ * <li>ozone genconf -h</li>
  * </ul>
  */
-public final class GenerateOzoneRequiredConfigurations {
-
-  private static final String OUTPUT = "-output";
-  private static final String HELP = "-help";
-  private static final String USAGE = "Usage: \nozone genconf "
-      + OUTPUT + " <Path to output file> \n"
-      + "ozone genconf "
-      + HELP;
-  private static final int SUCCESS = 0;
-  private static final int FAILURE = 1;
+@Command(
+    name = "ozone genconf",
+    description = "Tool to generate template ozone-site.xml",
+    versionProvider = HddsVersionProvider.class,
+    mixinStandardHelpOptions = true)
+public final class GenerateOzoneRequiredConfigurations extends GenericCli {
 
-  private GenerateOzoneRequiredConfigurations() {
+  @Parameters(arity = "1..1",
+      description = "Directory path where ozone-site file should be generated.")
+  private String path;
 
-  }
   /**
    * Entry point for using genconf tool.
    *
    * @param args
-   * @throws JAXBException
-   */
-  public static void main(String[] args) {
-
-    try {
-      if (args.length == 0) {
-        System.out.println(USAGE);
-        System.exit(1);
-      }
-
-      switch (args[0]) {
-      case OUTPUT:
-        if (args.length > 1) {
-          int result = generateConfigurations(args[1]);
-        } else {
-          System.out.println("Path to output file is mandatory");
-          System.out.println(USAGE);
-          System.exit(1);
-        }
-        break;
-
-      case HELP:
-        System.out.println(USAGE);
-        System.exit(0);
-        break;
-
-      default:
-        System.out.println(USAGE);
-        System.exit(1);
-      }
-
-    } catch (Exception e) {
-      e.printStackTrace();
-    }
-  }
-
-  /**
-   * Check if the path is valid directory.
    *
-   * @param path
-   * @return true, if path is valid directory, else return false
    */
-  public static boolean isValidPath(String path) {
-    try {
-      return Files.isDirectory(Paths.get(path));
-    } catch (InvalidPathException | NullPointerException ex) {
-      return false;
-    }
+  public static void main(String[] args) throws Exception {
+    new GenerateOzoneRequiredConfigurations().run(args);
   }
 
-  /**
-   * Check if user has permission to write in the specified path.
-   *
-   * @param path
-   * @return true, if the user has permission to write, else returns false
-   */
-  public static boolean canWrite(String path) {
-    File file = new File(path);
-    return file.canWrite();
+  @Override
+  public Void call() throws Exception {
+    generateConfigurations(path);
+    return null;
   }
 
   /**
    * Generate ozone-site.xml at specified path.
-   *
    * @param path
-   * @return SUCCESS(0) if file can be generated, else returns FAILURE(1)
+   * @throws PicocliException
    * @throws JAXBException
    */
-  public static int generateConfigurations(String path) throws JAXBException {
+  public static void generateConfigurations(String path) throws
+      PicocliException, JAXBException {
 
     if (!isValidPath(path)) {
-      System.out.println("Invalid directory path.");
-      return FAILURE;
+      throw new PicocliException("Invalid directory path.");
     }
 
     if (!canWrite(path)) {
-      System.out.println("Insufficient permission.");
-      return FAILURE;
+      throw new PicocliException("Insufficient permission.");
     }
 
     OzoneConfiguration oc = new OzoneConfiguration();
@@ -168,7 +119,30 @@ public final class GenerateOzoneRequiredConfigurations {
     m.marshal(requiredConfig, new File(path, "ozone-site.xml"));
 
     System.out.println("ozone-site.xml has been generated at " + path);
+  }
+
+  /**
+   * Check if the path is valid directory.
+   *
+   * @param path
+   * @return true, if path is valid directory, else return false
+   */
+  public static boolean isValidPath(String path) {
+    try {
+      return Files.isDirectory(Paths.get(path));
+    } catch (InvalidPathException | NullPointerException ex) {
+      return Boolean.FALSE;
+    }
+  }
 
-    return SUCCESS;
+  /**
+   * Check if user has permission to write in the specified path.
+   *
+   * @param path
+   * @return true, if the user has permission to write, else returns false
+   */
+  public static boolean canWrite(String path) {
+    File file = new File(path);
+    return file.canWrite();
   }
 }

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

@@ -21,23 +21,40 @@ package org.apache.hadoop.ozone.genconf;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.lang3.RandomStringUtils;
 import org.apache.hadoop.test.GenericTestUtils;
-import org.hamcrest.CoreMatchers;
+import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.Assert;
+import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import picocli.CommandLine;
+import picocli.CommandLine.ExecutionException;
+import picocli.CommandLine.IExceptionHandler2;
+import picocli.CommandLine.ParseResult;
+import picocli.CommandLine.ParameterException;
 
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.PrintStream;
-
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 
 /**
  * Tests GenerateOzoneRequiredConfigurations.
  */
 public class TestGenerateOzoneRequiredConfigurations {
   private static File outputBaseDir;
+  private static GenerateOzoneRequiredConfigurations genconfTool;
+  private static final Logger LOG =
+      LoggerFactory.getLogger(TestGenerateOzoneRequiredConfigurations.class);
+  private final ByteArrayOutputStream out = new ByteArrayOutputStream();
+  private final ByteArrayOutputStream err = new ByteArrayOutputStream();
+  private static final PrintStream OLD_OUT = System.out;
+  private static final PrintStream OLD_ERR = System.err;
   /**
    * Creates output directory which will be used by the test-cases.
    * If a test-case needs a separate directory, it has to create a random
@@ -49,6 +66,24 @@ public class TestGenerateOzoneRequiredConfigurations {
   public static void init() throws Exception {
     outputBaseDir = GenericTestUtils.getTestDir();
     FileUtils.forceMkdir(outputBaseDir);
+    genconfTool = new GenerateOzoneRequiredConfigurations();
+  }
+
+  @Before
+  public void setup() throws Exception {
+    System.setOut(new PrintStream(out));
+    System.setErr(new PrintStream(err));
+  }
+
+  @After
+  public void reset() {
+    // reset stream after each unit test
+    out.reset();
+    err.reset();
+
+    // restore system streams
+    System.setOut(OLD_OUT);
+    System.setErr(OLD_ERR);
   }
 
   /**
@@ -59,6 +94,57 @@ public class TestGenerateOzoneRequiredConfigurations {
     FileUtils.deleteDirectory(outputBaseDir);
   }
 
+  private void execute(String[] args, String msg) {
+    List<String> arguments = new ArrayList(Arrays.asList(args));
+    LOG.info("Executing shell command with args {}", arguments);
+    CommandLine cmd = genconfTool.getCmd();
+
+    IExceptionHandler2<List<Object>> exceptionHandler =
+        new IExceptionHandler2<List<Object>>() {
+          @Override
+          public List<Object> handleParseException(ParameterException ex,
+              String[] args) {
+            throw ex;
+          }
+
+          @Override
+          public List<Object> handleExecutionException(ExecutionException ex,
+              ParseResult parseResult) {
+            throw ex;
+          }
+        };
+    cmd.parseWithHandlers(new CommandLine.RunLast(),
+        exceptionHandler, args);
+    Assert.assertTrue(out.toString().contains(msg));
+  }
+
+  private void executeWithException(String[] args, String msg) {
+    List<String> arguments = new ArrayList(Arrays.asList(args));
+    LOG.info("Executing shell command with args {}", arguments);
+    CommandLine cmd = genconfTool.getCmd();
+
+    IExceptionHandler2<List<Object>> exceptionHandler =
+        new IExceptionHandler2<List<Object>>() {
+          @Override
+          public List<Object> handleParseException(ParameterException ex,
+              String[] args) {
+            throw ex;
+          }
+
+          @Override
+          public List<Object> handleExecutionException(ExecutionException ex,
+              ParseResult parseResult) {
+            throw ex;
+          }
+        };
+    try{
+      cmd.parseWithHandlers(new CommandLine.RunLast(),
+          exceptionHandler, args);
+    }catch(Exception ex){
+      Assert.assertTrue(ex.getMessage().contains(msg));
+    }
+  }
+
   /**
    * Tests a valid path and generates ozone-site.xml by calling
    * {@code GenerateOzoneRequiredConfigurations#generateConfigurations}.
@@ -68,79 +154,54 @@ public class TestGenerateOzoneRequiredConfigurations {
   @Test
   public void testGenerateConfigurations() throws Exception {
     File tempPath = getRandomTempDir();
-    String[] args = new String[]{"-output", tempPath.getAbsolutePath()};
-
-    Assert.assertEquals("Path is valid",
-        true, GenerateOzoneRequiredConfigurations.isValidPath(args[1]));
-
-    Assert.assertEquals("Permission is valid",
-        true, GenerateOzoneRequiredConfigurations.canWrite(args[1]));
-
-    Assert.assertEquals("Config file generated",
-        0, GenerateOzoneRequiredConfigurations.generateConfigurations(args[1]));
+    String[] args = new String[]{tempPath.getAbsolutePath()};
+    execute(args, "ozone-site.xml has been generated at " +
+        tempPath.getAbsolutePath());
   }
 
   /**
-   * Tests ozone-site.xml generation by calling
-   * {@code GenerateOzoneRequiredConfigurations#main}.
-   *
+   * Test to avoid generating ozone-site.xml when insufficient permission.
    * @throws Exception
    */
   @Test
-  public void testGenerateConfigurationsThroughMainMethod() throws Exception {
+  public void genconfFailureByInsufficientPermissions() throws Exception {
     File tempPath = getRandomTempDir();
-    String[] args = new String[]{"-output", tempPath.getAbsolutePath()};
-    ByteArrayOutputStream outContent = new ByteArrayOutputStream();
-    PrintStream oldStream = System.out;
-    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"));
-      System.setOut(oldStream);
-    }
+    tempPath.setReadOnly();
+    String[] args = new String[]{tempPath.getAbsolutePath()};
+    executeWithException(args, "Insufficient permission.");
   }
 
   /**
-   * Test to avoid generating ozone-site.xml when invalid permission.
+   * Test to avoid generating ozone-site.xml when invalid path.
    * @throws Exception
    */
   @Test
-  public void generateConfigurationsFailure() throws Exception {
+  public void genconfFailureByInvalidPath() throws Exception {
     File tempPath = getRandomTempDir();
-    tempPath.setReadOnly();
-    String[] args = new String[]{"-output", tempPath.getAbsolutePath()};
-    GenerateOzoneRequiredConfigurations.main(args);
-
-    Assert.assertEquals("Path is valid",
-        true, GenerateOzoneRequiredConfigurations.isValidPath(args[1]));
-
-    Assert.assertEquals("Invalid permission",
-        false, GenerateOzoneRequiredConfigurations.canWrite(args[1]));
-
-    Assert.assertEquals("Config file not generated",
-        1, GenerateOzoneRequiredConfigurations.generateConfigurations(args[1]));
-    tempPath.setWritable(true);
+    String[] args = new String[]{"invalid-path"};
+    executeWithException(args, "Invalid directory path.");
   }
 
   /**
-   * Test to avoid generating ozone-site.xml when invalid permission.
+   * Test to avoid generating ozone-site.xml when path not specified.
    * @throws Exception
    */
   @Test
-  public void generateConfigurationsFailureForInvalidPath() throws Exception {
+  public void genconfPathNotSpecified() 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]));
+    String[] args = new String[]{};
+    executeWithException(args, "Missing required parameter: <path>");
+  }
 
-    Assert.assertEquals("Config file not generated", 1,
-        GenerateOzoneRequiredConfigurations.generateConfigurations(args[1]));
-    tempPath.setWritable(true);
+  /**
+   * Test to check help message.
+   * @throws Exception
+   */
+  @Test
+  public void genconfHelp() throws Exception {
+    File tempPath = getRandomTempDir();
+    String[] args = new String[]{"--help"};
+    execute(args, "Usage: ozone genconf [-hV] [--verbose]");
   }
 
   private File getRandomTempDir() throws IOException {