This is a heads-up for the ones running Ubuntu 18.04 and using OpenNMS services with Docker. Be aware when you update to the latest kernel image 4.15.0-60 there are issues reported where the system crashes and reboots. I’ve noticed this issue by myself especially when you start Docker container images on system start.
The issue was noticed in the mailcow project and is documented here.
There is a bug with a fix is registered in Bug #1842447.
A workaround for this issue, for now, is a rollback to an older kernel image like 4.15.0-58-generic.