ELK pragma not supported in docker container

[RufusJWB]

Describe the bug
The ELK pragma (https://forum.plantuml.net/13709/eclipse-layout-kernel) not supported in docker image

To Reproduce

1. Run PlantUML as docker container
2. Try to render a diagram including !pragma layout elk

Expected behavior
Should render without error

Screenshots
see above

[fchastanet]

I succeed to generate an image of my diagram with elk layout using this command:

docker run -i \
  -v /opt/java/elk-full.jar:/opt/elk-full.jar \
  --rm plantuml/plantuml -tpng -v -pipe -failfast2 -nbthread auto \
  -DPLANTUML_LIMIT_SIZE=24384 > schema.png < schema.puml

change accordingly /opt/java/elk-full.jar to the path where elk-full.jar is installed on your computer

[arnaudroques]

We've encountered a new issue with ELK and could use some help. Check out the details here: GitHub Issue #336.

Any assistance would be greatly appreciated!