[FR]: Generate venv at build time

[thesayyn]

What is the current behavior?

This is a tracking issue for all things related to venv generation at build time. Biggest issue so far is when running py_binary put into a docker image on Lambda, it simply does not work since all the paths on Lambda is write protected.

Current issues with venv

#433
#373
#351
#339

Describe the feature

Generate the venv at Build time by making the venv relocatable.

[thesayyn]

Blocker: #339 (comment)

[vinnybod]

I think I am blocked on this.

I am trying to create a python environment on an OCI image that has a few dependencies pre-installed. It doesn't seem possible to have the venv already created in the image. It also doesn't seem possible to symlink the venv in the $PATH and still contain the 3rd party dependencies.

https://github.com/vinnybod/bazel-examples/tree/python-oci/python-oci