HDDS-11838. Top-level shell to allow access to admin/debug/sh commands

Author: will-sh

hadoop-ozone/cli-shell/src/main/java/org/apache/hadoop/ozone/shell/OzoneInteractiveShell.java

@@ -18,6 +18,9 @@
 package org.apache.hadoop.ozone.shell;
 
 import org.apache.hadoop.hdds.cli.GenericCli;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import picocli.CommandLine;
 import picocli.CommandLine.Command;
 import picocli.shell.jline3.PicocliCommands.PicocliCommandsFactory;
@@ -27,6 +30,8 @@
  */
 public final class OzoneInteractiveShell {
 
+  private static final Logger LOG = LoggerFactory.getLogger(OzoneInteractiveShell.class);
+
   private OzoneInteractiveShell() {
   }
 
@@ -66,15 +71,16 @@ private static void addDynamicSubcommand(CommandLine topCmd, String name, String
       GenericCli instance = (GenericCli) clazz.getDeclaredConstructor().newInstance();
       topCmd.addSubcommand(name, instance.getCmd());
     } catch (Exception e) {
-      // Ignore if the class is not present in the classpath
+      LOG.debug("Subcommand {} not loaded: class {} not found or could not be instantiated", 
+          name, className, e);
     }
   }
 
   @Command(name = "ozone", description = "Interactive Shell for all Ozone commands", mixinStandardHelpOptions = true)
   private static class TopCommand implements Runnable {
     @Override
     public void run() {
-      // Top level command doesn't do anything by itself in REPL
+      // The top-level command is only used to group subcommands and has no execution logic itself.
     }
   }
 }