ShinyProxy Swarm service breaks after restart


First of all, thank you for your effort and dedication!

I’m trying to set up a CentOS-based OpenStack cluster running ShinyProxy as a Docker Swarm service. A fresh installation (done with Terraform+Ansible) works fine, but when I interfere with ShinyProxy in any way (running docker service update, restarting the container, removing the service and registering it again), it crashes at startup with an exception:

Backend is not a Docker Swarm

It’s not even possible to re-set it up with the same Ansible script that was used to install it.
I believe this is specific to ShinyProxy, since Jenkins installed in the same way “wakes up” easily after a restart.
Is this a bug or a configuration issue on my side?

Side question (closely related to my problem): Have you established an elegant, out-of-the-box way to update apps bound to ShinyProxy running in a swarm (or are you planning to do so)? It’s easy to perform updates when the same tag is used across all versions/images of the app, but in a production environment it would be nice to have a more sophisticated mechanism.