How to access individual containers in Hass.io?

Hi all,
My core problem is, that I have NodeRED running inside Hass.io, where I want to invoke some Python scripts (integration to the system I want to use is available in Python and not in JS).

NodeRED has nodes for this, but as the installation is running in a container, I have no way of accessing the container. Normally, I’d simply SSH into the container with tools from Docker, download the Python file, and start setting up my nodes, but neither the Resin CLI or Docker’s CLI is available in Hass.io.

Any suggestions on how to proceed?