Add instructions about installing pants in docker

[nrontsis]

Add some instruction on installing pants in docker and airtight environments as per #22942 (comment)

[sureshjoshi]

Hey @nrontsis - just to clarify here, I know you use uv a lot, but this workflow would work for those who use a python3.11-slim and then just pip install too, right?

Or would that lead to any hiccups?

[nrontsis]

Hey @sureshjoshi

this workflow would work for those who use a python3.11-slim and then just pip install too, right?

yes, the following works

FROM python:3.11-slim
ENV NO_SCIE_WARNING=True
ENV PANTS_VERSION=2.30.0
RUN pip install https://github.com/pantsbuild/pants/releases/download/release_${PANTS_VERSION}/pantsbuild_pants-${PANTS_VERSION}-cp311-cp311-manylinux2014_x86_64.whl

but it assumes that the user's docker image comes with python 3.11 (cause pants only publishes wheels for python 3.11), and that the user is happy to mutate the global python env. Otherwise the user will need to install manually python 3.11 (perhaps in conjuction with another python version they need for their app), a pip on that python and perhaps a virtualenv.

My intention was to avoid these assumptions and to provide an example Dockerfile that can work for a wide range of base images.

[sureshjoshi]

Lost this as I wasn't marked as a reviewer.