Comment 5 for bug 1798656

I also experience this problem on Ubuntu Xenial. The prompt is:

 ┌───────────────────────────────────────────────────────────┤ Configuring docker.io ├────────────────────────────────────────────────────────────┐
  │ │
  │ If Docker is upgraded without restarting the Docker daemon, Docker will often have trouble starting new containers, and in some cases even │
  │ maintaining the containers it is currently running. See https://launchpad.net/bugs/1658691 for an example of this breakage. │
  │ │
  │ Normally, upgrading the package would simply restart the associated daemon(s). In the case of the Docker daemon, that would also imply │
  │ stopping all running containers (which will only be restarted if they're part of a "service", have an appropriate restart policy configured, │
  │ or have some other means of being restarted such as an external systemd unit). │
  │ │
  │ Automatically restart Docker daemon? │
  │ │
  │ <Yes> <No> │
  │ │
  └────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

It's seems to be not configurable by dpkg --set-selections:

root@server# dpkg --get-selections docker.io
docker.io install

I could upload a vagrant box to demonstrate this issue when running apt-get upgrade -y. I try to automate the upgrade process, but this atm blocks the upgrade and CI pipelines with interactive prompt. I'm also trying to build a workaround wrapper with expect.