Exception NoClassDefFoundError org/testcontainers/utility/PathUtils

[nicolas-lattuada-n26]

Hello

There is an exception in MountableFile, it does not find the class PathUtils when it calls recursiveDeleteDir from shutdownHook.
I think this is because during the shutdown hook the class loader is already closed by Maven and cannot be used to load new classes.

See attached stack trace

Exception in thread "Thread-17" java.lang.NoClassDefFoundError: org/testcontainers/utility/PathUtils$1
	at org.testcontainers.utility.PathUtils.recursiveDeleteDir(PathUtils.java:26)
	at org.testcontainers.utility.MountableFile.lambda$deleteOnExit$0(MountableFile.java:284)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.ClassNotFoundException: org.testcontainers.utility.PathUtils$1
	at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
	... 3 more

[bsideup]

@nicolas-lattuada-n26 could you please create an example to reproduce this?

[nicolas-lattuada-n26]

Unfortunately this is included in proprietary code that I cannot disclose here, but I think if you include a call to MountableFile from a maven plugin you should be able to reproduce it.

[bsideup]

@nicolas-lattuada-n26 sorry, but this sounds too specific.
It may also be a bug in Maven's classloading mechanism, so I suggest creating a minimal reproducer to verify it.

[nicolas-lattuada-n26]

Hello @bsideup
Thanks for your reply, it took me some time to create a minimum project so that you can reproduce.
https://github.com/nicolas-lattuada-n26/sample-plugin
cc/ @Osguima3

[nicolas-lattuada-n26]

Hello @bsideup
Have you been able to run the test project provided yet?

[flylo]

Running into this same issue

[DuckyCh]

Same error here.

[rnorth]

Hmm, I'm not really sure if we can help much with this. Running Testcontainers code directly from a Maven plugin isn't something we've attempted to support, as we're more focused on testing. I assume your usage scenarios are not testing?

As you say it does look like the Maven classloader closing is what's causing it. If that's Maven's classloader behaviour then I imagine shutdown hooks are essentially not safe inside of a Maven plugin, and should be avoided.

If there's something simple that we could change then I think we could accept a PR, but otherwise I'm afraid we might have to chalk this up as an unsupported use case. Sorry to disappoint.

[heruan]

I'm still suffering this. My Maven plugin is for testing purposes and runs a few database containers, which per se succeeds but I get that exception at last which fails the CI build.

[flylo]

@heruan fwiw I just run this stupid util in a finally block to suppress the exceptions. Could have some bad side-effects, however.

package com.lol.utils;

import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;

public class PwnageUtils {

  // removes the shutdown hooks from testcontainers threads because they will fail after mojo closure context closes.
  // this is obviously horrible, but it stops us from getting pwned by classloader exceptions after successful builds.
  public static void stopPwnage() {
    try {
      Class clazz = Class.forName("java.lang.ApplicationShutdownHooks");
      Field field = clazz.getDeclaredField("hooks");
      field.setAccessible(true);
      Map<Thread, Thread> hooks = (Map<Thread, Thread>) field.get(null);
      // Need to create a new map or else we'll get CMEs
      Map<Thread, Thread> hookMap = new HashMap<>();
      hooks.forEach(hookMap::put);
      hookMap.forEach((thread, hook) -> {
        if (thread.getThreadGroup().getName().toLowerCase().contains("testcontainers")) {
          Runtime.getRuntime().removeShutdownHook(hook);
        }
      });
    } catch (Exception e) {
      throw new RuntimeException("pwned", e);
    }
  }
}

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. If you believe this is a mistake, please reply to this comment to keep it open. If there isn't one already, a PR to fix or at least reproduce the problem in a test case will always help us get back on track to tackle this.