When installing docker-ce on fedora 31 it does not work out of the box as Fedora 31 uses cgroups v2 by default and docker doesn’t yet support cgroupsv2.

To solve this, edit grub config:

sudo gedit /etc/default/grub

Add the parameter systemd.unified_cgroup_hierarchy=0 to the line starting by GRUB_CMDLINE_LINUX

Now update grub by running:

grub2-mkconfig

And reboot the system.