How do I install python packages inside of a singularity container?

Question

I am trying to install packages with pip on my singularity container, but there seems to be no way of doing so without "borrowing" the packages from my machine. I have heard that I may need to use virtualenv's but even that seems to be a circuitous process. Does anyone know of a tried and true way of using packages from pip on their singularity container?

Answer 1

How are you building your container? You should be able to use pip inside the container just like you would installing on an actual machine.

Here is an example:

Bootstrap: docker
From: python:3.7-alpine

%post 
    pip install click 

Save this as a file, like test.def, then just build the container:

sudo singularity build test.sif test.def

The build a container document will help.