The installation on eoan fails with a missing dependency for containerd.io not having an install candidate.

Fix

Edit your /etc/apt/sources.list file and change the eoan version to disco. Or remove the line and re-add it using:

$ sudo add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   disco \
   stable"

It may still fail to install with an error docker.service Failed with result 'start-limit-hit'. A reboot soon sorted it out followed by a call to apt install.

$ apt install -f