How to use -v flag with Jupyterhub and Dockerspawner

I’m currently running a jupyterhub service on Ubuntu VM’s for use in training. I utilise dockerspawner, more specifically systemuserspawner, to generate individual notebook servers. I now want to give some instruction on how to use docker. I read Jérôme Petazzoni’s blog on how to use the -v flag to give access to the host docker socket, but I’m unable to implement it as I don’t know where the docker run command is being given. Any advice greatly appreciated.

Some details about my setup:
Host machine is running Ubuntu 16.04
Jupyterhub is version 0.7.2
Docker version 17.12.0-ce, build c97c6d6
Initial notebook image is jupyter/datascience-notebook:82b978b3ceeb