How to expose javaagent class to applications/modules in Wildfly?

[jessholle]

I have a simple javaagent that I am currently using with Wildfly 8.1.0.

Now, however, I'd like to do further instrumentation where classes in Wildfly modules and/or applications can access the same class instances loaded in the Java agent, i.e. so objects like Instrumentation (or methods using such objects) can be shared from the javaagent to modules and/or applications.

This just works if I have a simple Java application, but the application server and module mechanisms in Wildfly hide these class instances by default -- and I can't figure out how to expose them again.

I have gotten the classes exposed -- that's easy.  What I cannot figure out is how to get the same instances of these classes used by javaagent exposed, i.e. so that the Instrumentation object and other objects and functionalities based on these can be shared with downstream modules and applications.

Any pointers?

[ctomc]

Take a look at standalone.conf / standalone.conf.bat

this is how we expose bytman agent classes.

if [ "x$JBOSS_MODULES_SYSTEM_PKGS" = "x" ]; then

  JBOSS_MODULES_SYSTEM_PKGS="org.jboss.byteman"

fi

[jessholle]

This turns out to be the correct answer.

I'd already tried this, but there's a catch: JBOSS_MODULES_SYSTEM_PKGS is unused on Windows, so if you set this hoping to achieve this effect you get nowhere!

If, however, you add -Djboss.modules.system.pkgs=... to your JVM options, that works as expected.

It would be best if environment variables were consistently supported across platforms to avoid surprises like this one.

[ctomc]

Ah that is a bug than, can you open jira for it.

tnx