External Task Worker native image

[ChrisSchoe]

Hi Everyone,
a few months ago I implemented an external task worker using the Camunda external task client and Quarkus. Everything worked fine in JVM mode but I had some trouble getting the native image to work properly. Somehow, the client would not subscribe properly. I left it at that as it was just a pet project, but I am wondering whether you faced similar issues. Does your external task worker example with Micronaut also function when built as a native image?
Thanks
Chris

[tobiasschaefer]

@ChrisSchoe : We have managed to start our example application at https://github.com/NovatecConsulting/micronaut-camunda-bpm/tree/master/micronaut-camunda-bpm-example some time ago, but we haven't tried https://github.com/NovatecConsulting/micronaut-camunda-bpm/tree/master/example-external-task-worker.

Do you remember more details to "would not subscribe properly"? Did it work at all?

We'll check and then come back to you.

[ChrisSchoe]

Hey Tobias,
thanks for the quick reply! I tried to replicate my bug and found that despite all variables being set properly the engine still complained about the worker ID not being set when subscribing. However, just now I was able to solve this problem by manually registering some classes of the External Task Client for reflection. My best guess would be that the package internally uses reflection to build its requests, thus not playing nicely with Graal. So thanks for causing me to think about this problem again and heads up as this is something that I guess would also be an issue when using the Micronaut native image of your external worker example =)
Best wishes

[tobiasschaefer]

Hi @ChrisSchoe ,

yes, you need a reflection configuration for GraalVM. My external worker is up and running after 32 ms.

Just to have a comparison: the Ueber Jar created with the shadowJar plugins needs 840 ms to start.

If everything is clarified then please mark this question as answered. Thanks.