Docker stops loading after reboot.
It seems that following the kernel upgrade to patch the Meltdown vulnerabilities, my Docker container is no longer booting on startup.
When you initially set up Docker it is typically configured to use a generic kernel. So once the kernel version is updated or changed Docker is still looking to use the older kernel. If you check
/var/log/apt/history.log it will show you if your server has recently installed a new kernel. If so then you will need to upgrade your Docker image to work with that new kernel. I think that this Ubuntu page breaks down the various Linux images best.