pip install into a Python container's virtualenv

[iaindillingham]

I'd like to be able to pip install into a Python container's virtualenv. Doing so would allow me to use profiling tools from within IPython, as described in Profiling and Timing Code in the Python Data Science Handbook.

If I run

docker run --interactive --tty --volume $(pwd):/workspace --entrypoint ipython ghcr.io/opensafely-core/python:latest

then I can

!pip install memory_profiler

from within IPython. However, if I run

opensafely exec python:latest ipython

then pip install fails, because it doesn't have permission to write to /opt/venv.