HADOOP-17665 Ignore missing keystore configuration in reloading mechanism

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer2.java

@@ -27,6 +27,7 @@ import java.net.InetSocketAddress;
 import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URL;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.List;
 import java.util.ArrayList;
@@ -587,7 +588,8 @@ public final class HttpServer2 implements FilterContainer {
           conf.getLong(FileBasedKeyStoresFactory.SSL_STORES_RELOAD_INTERVAL_TPL_KEY,
               FileBasedKeyStoresFactory.DEFAULT_SSL_STORES_RELOAD_INTERVAL);
 
-      if (storesReloadInterval > 0) {
+      if (storesReloadInterval > 0 &&
+          (keyStore != null || trustStore != null)) {
         this.configurationChangeMonitor = Optional.of(
             this.makeConfigurationChangeMonitor(storesReloadInterval, sslContextFactory));
       }
@@ -601,22 +603,30 @@ public final class HttpServer2 implements FilterContainer {
     private Timer makeConfigurationChangeMonitor(long reloadInterval,
         SslContextFactory.Server sslContextFactory) {
       java.util.Timer timer = new java.util.Timer(FileBasedKeyStoresFactory.SSL_MONITORING_THREAD_NAME, true);
+      ArrayList<Path> locations = new ArrayList<Path>();
+      if (keyStore != null) {
+        locations.add(Paths.get(keyStore));
+      }
+      if (trustStore != null) {
+        locations.add(Paths.get(trustStore));
+      }
       //
       // The Jetty SSLContextFactory provides a 'reload' method which will reload both
       // truststore and keystore certificates.
       //
       timer.schedule(new FileMonitoringTimerTask(
-              Paths.get(keyStore),
-              path -> {
-                LOG.info("Reloading certificates from store keystore " + keyStore);
-                try {
-                  sslContextFactory.reload(factory -> { });
-                } catch (Exception ex) {
-                  LOG.error("Failed to reload SSL keystore certificates", ex);
-                }
-              },null),
-          reloadInterval,
-          reloadInterval
+            locations,
+            path -> {
+              LOG.info("Reloading keystore and truststore certificates.");
+              try {
+                sslContextFactory.reload(factory -> { });
+              } catch (Exception ex) {
+                LOG.error("Failed to reload SSL keystore " +
+                    "and truststore certificates", ex);
+              }
+            },null),
+        reloadInterval,
+        reloadInterval
       );
       return timer;
     }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/ssl/FileMonitoringTimerTask.java

@@ -24,6 +24,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 import java.util.TimerTask;
 import java.util.function.Consumer;
 
@@ -42,34 +45,59 @@ public class FileMonitoringTimerTask extends TimerTask {
   static final String PROCESS_ERROR_MESSAGE =
       "Could not process file change : ";
 
-  final private Path filePath;
+  final private List<Path> filePaths;
   final private Consumer<Path> onFileChange;
   final Consumer<Throwable> onChangeFailure;
-  private long lastProcessed;
+  private List<Long> lastProcessed;
 
   /**
-   * Create file monitoring task to be scheduled using a standard Java {@link java.util.Timer}
-   * instance.
+   * See {@link #FileMonitoringTimerTask(List, Consumer, Consumer)}.
    *
-   * @param filePath The path to the file to monitor.
-   * @param onFileChange The function to call when the file has changed.
-   * @param onChangeFailure The function to call when an exception is thrown during the
-   *                       file change processing.
+   * @param filePath The file to monitor.
+   * @param onFileChange What to do when the file changes.
+   * @param onChangeFailure What to do when <code>onFileChange</code>
+   *                        throws an exception.
    */
   public FileMonitoringTimerTask(Path filePath, Consumer<Path> onFileChange,
-      Consumer<Throwable> onChangeFailure) {
-    Preconditions.checkNotNull(filePath, "path to monitor disk file is not set");
-    Preconditions.checkNotNull(onFileChange, "action to monitor disk file is not set");
+                                 Consumer<Throwable> onChangeFailure) {
+    this(Collections.singletonList(filePath), onFileChange, onChangeFailure);
+  }
 
-    this.filePath = filePath;
-    this.lastProcessed = filePath.toFile().lastModified();
+  /**
+   * Create file monitoring task to be scheduled using a standard
+   * Java {@link java.util.Timer} instance.
+   *
+   * @param filePaths The path to the file to monitor.
+   * @param onFileChange The function to call when the file has changed.
+   * @param onChangeFailure The function to call when an exception is
+   *                       thrown during the file change processing.
+   */
+  public FileMonitoringTimerTask(List<Path> filePaths,
+                                 Consumer<Path> onFileChange,
+                                 Consumer<Throwable> onChangeFailure) {
+    Preconditions.checkNotNull(filePaths,
+        "path to monitor disk file is not set");
+    Preconditions.checkNotNull(onFileChange,
+        "action to monitor disk file is not set");
+
+    this.filePaths = new ArrayList<Path>(filePaths);
+    this.lastProcessed = new ArrayList<Long>();
+    this.filePaths.forEach(path ->
+        this.lastProcessed.add(path.toFile().lastModified()));
     this.onFileChange = onFileChange;
     this.onChangeFailure = onChangeFailure;
   }
 
   @Override
   public void run() {
-    if (lastProcessed != filePath.toFile().lastModified()) {
+    int modified = -1;
+    for (int i = 0; i < filePaths.size() && modified < 0; i++) {
+      if (lastProcessed.get(i) != filePaths.get(i).toFile().lastModified()) {
+        modified = i;
+      }
+    }
+    if (modified > -1) {
+      Path filePath = filePaths.get(modified);
       try {
         onFileChange.accept(filePath);
       } catch (Throwable t) {
@@ -79,7 +107,7 @@ public class FileMonitoringTimerTask extends TimerTask {
           LOG.error(PROCESS_ERROR_MESSAGE + filePath.toString(), t);
         }
       }
-      lastProcessed = filePath.toFile().lastModified();
+      lastProcessed.set(modified, filePath.toFile().lastModified());
     }
   }
 }

hadoop-yarn-project/hadoop-yarn/pom.xml

@@ -246,4 +246,5 @@
     <module>hadoop-yarn-ui</module>
     <module>hadoop-yarn-csi</module>
   </modules>
+  <!--  -->
 </project>