ComfyUI in Docker - how do I install custom nodes, and clone Comfy? And any other post-install necessities.

I'm on Pop!_OS. I finally managed to run ComfyUI in Docker successfully. I used this repo and their wiki's guides. I tested the default workflow, and it generated the image.

But it had no ComfyUI manager. I sudo git cloned it into the custom nodes folder, but when I restarted ComfyUI, it failed to import it. It doesn't have 'git' module.

My previous non-Docker ComfyUI got kinda broken because I tried to update some dependency for some node. So before I try doing something with no idea of what I'm doing, I decided to ask first.

How do I get the 'git' module, and is there any other thing I should be getting too? I noticed that pytorch 2.3 was installed, so it seems I need to upgrade stuff too, but I don't know how. The guide mentions creating a startup.sh for A1111 extensions, it mentions dependencies can conflict, and it recommends not messing with the Dockerfile.

I'd also like to know how I can make a clone of this base state of my ComfyUI Docker. That way I can install nodes for one ComfyUI but not the other, in case they conflict.