Source-to-Image (S2I) builders are available in OpenShift for a number of different Python versions. These all use Python from the Software Collections Library (SCL) and will pre-create a Python virtual environment for you, into which Python packages will be installed. Packaging tools such as pip will also be supplied.

As the version of virtualenv used to create the Python virtual environment also comes from SCL, it may not be the latest version. This means that packaging tools provided by the pip, wheel and setuptools packages may also not be the latest versions. This can be an issue when wanting to install Python packages from a Python wheel, as some Python wheels can require the latest version of pip and wheel tools to be available.

If a Python wheel file is not being used, or fails to install, you will need to upgrade the versions of pip, wheel and setuptools to the latest versions. If you are using the Python S2I builder, this can be triggered by setting the build time environment variable UPGRADE_PIP_TO_LATEST.

To set this environment variable on an existing build configuration, you can use the oc set env command on the build configuration.

$ oc set env bc/cookbook UPGRADE_PIP_TO_LATEST=true

and then trigger a new build.

$ oc start-build cookbook

If creating a new build or deployment, you can use the --build-env option to oc new-app or oc new-build.

$ oc new-app \
    python:3.5~https://github.com/openshift-katacoda/blog-django-py \
    --build-env UPGRADE_PIP_TO_LATEST=true

The environment variable can be set to any non empty value to trigger the upgrade. It is suggested to use the value true. If needing to later prevent the upgrade from occuring, you will need to delete the environment variable setting, or set it to an empty value.