Thank you for your answer Rich. I understand what you are saying and basically that is what I’m doing, but somehow this does not work for openHAB. Let me try to explain it a little bit more.
This is literally what is required to update any container. When you want to move to a new Docker image, you must create a new container based on that image. I would imagine that Portainer or Watchtower or whatever you use has a way to say “create a new container using this already existing cofiguration” and that is what you need to do to upgrade.
That is what Watchtower does and that is also what I do in Portainer. Do give you a better understanding, here is the description for what Watchtower does:
Watchtower will pull down your new image, gracefully shut down your existing container and restart it with the same options that were used when it was deployed initially.
That is also what I do when I recreate the container with a new Image in Portainer. In that case the old container gets deleted and a new container is created with the new image. But exactly here lies the problem. When I do this in Portainer (or Watchtower or the Synology UI), there are variables defined like OPENHAB_VERSION but when I now explicitly remove those variables, the new container with the new image still somehow adds the old variables again instead of the new ones from the new image.
While I’m writing this I maybe just found the problem…
It seems the Synology Docker package is broken (again since new newest version 9/2019) when it comes to recreating containers and creating environment variables.
Thank you again for your time. I hope that at least other people find this information useful when they run into this problem.
Another quick question: Since the update from 2.5.0 to 2.5.1 or higher, the Zwave binding is not working anymore when the serial port is defined through a symlink. Should I report this in Github or here in the forum? I’m not sure if the problem lies withing the binding or a change in serial port implementation which is used. I think I remember reading that the implementation changed, but I could also be mixing something up.