adapt run-java-sh to adopt the auto-generation options for Java 11

[vorburger]

@rhuss said in #160 that, quote:

major work will be to adapt https://github.com/fabric8io-images/run-java-sh to adopt the auto-generation options for the JDK. E.g. it would need a Java 8 / Java 11 dynamic detection (or taken from an env var) and use only the self-calculated cgroup based limits if not running on Java 11. Also, it would be awesome to update the fine-tuned options for Java 11 as well. A similar issue is open over there btw --> https://issues.jboss.org/browse/CLOUD-2839

But somewhat to my surprise, I seem to actually have been able to get a (basic) Java 11 working without touching run-java-sh ... I therefore propose that we work incrementally, and get #160 wrapped up and merged, and then iterate to improve things re. the point raised above under this issue.

[gunnarmorling]

I don't think it's too surprising that run-java.sh still works, but some of the things it's doing (like calculating default memory settings) shouldn't be needed any more with Java 11.

[vorburger]

https://github.com/fabric8io-images/run-java-sh/blob/master/fish-pepper/run-java-sh/fp-files/run-java.sh

https://github.com/fabric8io-images/s2i/blob/master/java/fish-pepper.yml#L17

[derkoe]

Already created a PR for this: fabric8io-images/run-java-sh#73 which is still not merged.

[rhuss]

#213 is a case where Java 11 breaks with the current script.

[rhuss]

#214 is the PR which includes the update to run-java with the fix for Java 11 included.

[vorburger]

@rhuss not sure if there is anything left to do here? (Other than perhaps #213.)

[rhuss]

Not sure either ;) I think if we have #213 done, we can close this issue, too.

[jerboaa]

With JDK-8146115 all of the size detection should be done automatically by the JVM. That includes JDK 8 (u191) and JDK 11. The relevant options are -Xlog:os+container=trace for JDK 11 and -XX:+UnlockDiagnosticVMOptions -XX:+PrintContainerInfo on JDK 8.

I cannot comment on other options those scripts use.

[rhuss]

@jerboaa thanks for the feedback. Actually, we should update run-java.sh either to detect also whether a Java 8 JDK supports the cgroup awareness automatically (and switch off the homegrown calculation in this case), or add an extra flag/env var to indicate that this is not needed anymore. The latter is probably is simpler (and then could be reused here when we are using the proper base image), but we might strive for the former, too.

Regardless what, works needs to be done over there in ghttps://github.com/fabric8io-images/run-java-sh