YARN-10130. FS-CS converter: Do not allow output dir to be the same as input dir. Contributed by Adam Antal

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/converter/FSConfigToCSConfigArgumentHandler.java

@@ -25,6 +25,7 @@ import org.apache.commons.cli.HelpFormatter;
 import org.apache.commons.cli.Option;
 import org.apache.commons.cli.Options;
 import org.apache.commons.cli.ParseException;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -39,6 +40,13 @@ public class FSConfigToCSConfigArgumentHandler {
   private static final Logger LOG =
       LoggerFactory.getLogger(FSConfigToCSConfigArgumentHandler.class);
 
+  private static final String ALREADY_CONTAINS_EXCEPTION_MSG =
+      "The %s (provided with %s|%s arguments) contains " +
+          "the %s provided with the %s|%s options.";
+  private static final String ALREADY_CONTAINS_FILE_EXCEPTION_MSG =
+      "The %s %s (provided with %s|%s arguments) already contains a file " +
+          "or directory named %s which will be the output of the conversion!";
+
   private FSConfigToCSConfigRuleHandler ruleHandler;
   private FSConfigToCSConfigConverterParams converterParams;
   private ConversionOptions conversionOptions;
@@ -213,6 +221,7 @@ public class FSConfigToCSConfigArgumentHandler {
     checkFile(CliOption.FAIR_SCHEDULER, fairSchedulerXmlFile);
     checkFile(CliOption.CONVERSION_RULES, conversionRulesFile);
     checkDirectory(CliOption.OUTPUT_DIR, outputDir);
+    checkOutputDirDoesNotContainXmls(yarnSiteXmlFile, outputDir);
 
     return FSConfigToCSConfigConverterParams.Builder.create()
         .withYarnSiteXmlConfig(yarnSiteXmlFile)
@@ -225,6 +234,45 @@ public class FSConfigToCSConfigArgumentHandler {
         .build();
   }
 
+  private static void checkOutputDirDoesNotContainXmls(String yarnSiteXmlFile,
+      String outputDir) {
+    if (yarnSiteXmlFile == null || outputDir == null) {
+      return;
+    }
+
+    // check whether yarn-site.xml is not in the output folder
+    File xmlFile = new File(yarnSiteXmlFile);
+    File xmlParentFolder = xmlFile.getParentFile();
+    File output = new File(outputDir);
+    if (output.equals(xmlParentFolder)) {
+      throw new IllegalArgumentException(
+          String.format(ALREADY_CONTAINS_EXCEPTION_MSG,
+              CliOption.OUTPUT_DIR.name, CliOption.OUTPUT_DIR.shortSwitch,
+              CliOption.OUTPUT_DIR.longSwitch, CliOption.YARN_SITE.name,
+              CliOption.YARN_SITE.shortSwitch,
+              CliOption.YARN_SITE.longSwitch));
+    }
+
+    // check whether the output folder does not contain nor yarn-site.xml
+    // neither capacity-scheduler.xml
+    checkFileNotInOutputDir(output,
+        YarnConfiguration.YARN_SITE_CONFIGURATION_FILE);
+    checkFileNotInOutputDir(output,
+        YarnConfiguration.CS_CONFIGURATION_FILE);
+  }
+
+  private static void checkFileNotInOutputDir(File output, String fileName) {
+    File file = new File(output, fileName);
+    if (file.exists()) {
+      throw new IllegalArgumentException(
+          String.format(ALREADY_CONTAINS_FILE_EXCEPTION_MSG,
+              CliOption.OUTPUT_DIR.name, output,
+              CliOption.OUTPUT_DIR.shortSwitch,
+              CliOption.OUTPUT_DIR.longSwitch,
+              fileName));
+    }
+  }
+
   private void printHelp(Options opts) {
     HelpFormatter formatter = new HelpFormatter();
     formatter.printHelp("General options are: ", opts);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/converter/FSConfigConverterTestCommons.java

@@ -35,7 +35,7 @@ import static org.junit.Assert.assertTrue;
  *
  */
 public class FSConfigConverterTestCommons {
-  private final static String TEST_DIR =
+  public final static String TEST_DIR =
       new File(System.getProperty("test.build.data", "/tmp")).getAbsolutePath();
   public final static String FS_ALLOC_FILE =
       new File(TEST_DIR, "test-fair-scheduler.xml").getAbsolutePath();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/converter/TestFSConfigToCSConfigArgumentHandler.java

@@ -20,10 +20,13 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.io.File;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
 
+import org.apache.commons.io.FileUtils;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
@@ -492,4 +495,64 @@ public class TestFSConfigToCSConfigArgumentHandler {
     assertFalse("No terminal rule check was enabled",
         conversionOptions.isNoRuleTerminalCheck());
   }
+
+  @Test
+  public void testYarnSiteOptionInOutputFolder() throws Exception {
+    setupFSConfigConversionFiles(true);
+
+    FSConfigToCSConfigArgumentHandler argumentHandler =
+        createArgumentHandler();
+
+    String[] args = new String[] {
+        "-y", FSConfigConverterTestCommons.YARN_SITE_XML,
+        "-o", FSConfigConverterTestCommons.TEST_DIR};
+
+    int retVal = argumentHandler.parseAndConvert(args);
+    assertEquals("Return value", -1, retVal);
+
+    assertTrue(fsTestCommons.getErrContent()
+        .toString().contains("contains the yarn-site.xml"));
+  }
+
+  private void testFileExistsInOutputFolder(String file) throws Exception {
+    File testFile = new File(FSConfigConverterTestCommons.OUTPUT_DIR, file);
+    try {
+      FileUtils.touch(testFile);
+
+      setupFSConfigConversionFiles(true);
+
+      FSConfigToCSConfigArgumentHandler argumentHandler =
+          createArgumentHandler();
+
+      String[] args = new String[] {
+          "-y", FSConfigConverterTestCommons.YARN_SITE_XML,
+          "-o", FSConfigConverterTestCommons.OUTPUT_DIR};
+
+      int retVal = argumentHandler.parseAndConvert(args);
+      assertEquals("Return value", -1, retVal);
+
+      String expectedMessage = String.format(
+          "already contains a file or directory named %s", file);
+
+      assertTrue(fsTestCommons.getErrContent()
+          .toString().contains(expectedMessage));
+    } finally {
+      if (testFile.exists()) {
+        testFile.delete();
+      }
+    }
+  }
+
+  @Test
+  public void testYarnSiteExistsInOutputFolder() throws Exception {
+    testFileExistsInOutputFolder(
+        YarnConfiguration.YARN_SITE_CONFIGURATION_FILE);
+  }
+
+  @Test
+  public void testCapacitySchedulerXmlExistsInOutputFolder()
+      throws Exception {
+    testFileExistsInOutputFolder(
+        YarnConfiguration.CS_CONFIGURATION_FILE);
+  }
 }