Prerequisites
Downloads
You will need a working kubernetes cluster and to follow the steps outlined in the atlantis documentation to cofigure it to work with a github repo and your cloud.
After that is done, you may also need to install supplemental tools within the pod to have it work with our terraform modules. The best way to do this is to fork their image and add in a step to install any supplemental tools. The likely ones you will need to install are helm, kubectl, aws and postgres.