virtualenv-seedhelper

A virtualenv seeder to seed wheels from a folder

Quick start

Install in system python environment

python3 -m pip install virtualenv-seedhelper

Configure virtualenv to always use seedhelper

seedhelper config

Note that this overwrites virtualenv.ini if it already exists.

Add wheels to SEEDHELPER_WHEELS_DIR one at a time by URL

seedhelper download https://files.pythonhosted.org/packages/f1/13/63c0a02c44024ee16f664e0b36eefeb22d54e93531630bd99e237986f534/cowsay-6.1-py3-none-any.whl

Create a new virtualenv

python3 -m virtualenv venv

Verify that the new virtualenv has the wheels installed in it

$ venv/bin/pip list
Package    Version
---------- -------
cowsay     6.1
pip        23.2.1
setuptools 68.2.2
wheel      0.41.2

What if we want to seed a package with dependencies?

Instead of looking up and downloading wheel URLs one by one, we can use seedhelper require to download the wheels for all the dependencies of a requirement, placing all of their wheels in the SEEDHELPER_WHEELS_DIR so that they all get seeded into newly-created virtualenvs.

seedhelper require requests==2.31.0

After this, we can make a new virtualenv

python3 -m virtualenv venv

and verify that it has all the dependencies installed

$ venv/bin/pip list
Package            Version
------------------ ---------
certifi            2023.7.22
charset-normalizer 3.3.0
idna               3.4
pip                23.2.1
requests           2.31.0
setuptools         68.2.2
urllib3            2.0.7
wheel              0.41.2

and we can import the package in the venv

venv/bin/python -c 'import requests'

Config

SEEDHELPER_WHEELS_DIR

This is where seedhelper will download wheels to. It defaults to ~/Library/Application Support/virtualenv/seedhelper_wheels (or the corresponding location on your specific platform as provided by platformdirs.user_config_dir()). You can override it by setting an environment variable called SEEDHELPER_WHEELS_DIR.

VIRTUALENV_CONFIG_FILE

This is where virtualenv (and seedhelper) will look for virtualenv.ini. It defaults to ~/Library/Application Support/virtualenv/virtualenv.ini (or the corresponding location on your specific platform as provided by platformdirs.user_config_dir()). You can override it by setting an environment variable called VIRTUALENV_CONFIG_FILE.

Motivation

The goal is to make it possible to include a set of wheels in every virtualenv created. This is especially useful when the system-wide pip configuration assumes that certain packages, such as keyring backends needed to interact with a private package index, will always be available before pip runs. Without a seeder, you cannot use pip to install the keyring because pip itself needs the keyring to be already installed in order to function at all.