These pre-exercises are designed to prepare you for using Docker in the context of the CMS Open Data Workshop. This is not a full introduction to Docker, however we do take time to explain some key concepts that should make your experience a smooth one.
Note that you can also use virtual machines (VMs) to interface with the CERN Open Data Portal and this workshop and there is a separate pre-exercise for that.
You should definitely take time to go through either this or the VM exercise before participating in the workshop.
If you run into problems with any of these steps, please reach out to the organizers through the dedicated Mattermost channel.