Comment 4 for bug 1991957

i was able to work around the install issue by using pip==20.0.2

this workaround can be applied with:

$ juju ssh kubernetes-control-plane/<unit>
$ sudo su -
$ rm /var/lib/juju/agents/unit-kubernetes-control-plane-*/charm/wheelhouse/pip-18.1.tar.gz
$ PIP_PKG=https://files.pythonhosted.org/packages/8e/76/66066b7bc71817238924c7e4b448abdb17eb0c92d645769c223f9ace478f/pip-20.0.2.tar.gz
$ wget $PIP_PKG -P /var/lib/juju/agents/unit-kubernetes-control-plane-*/charm/wheelhouse/

I tried all the versions of pip between 18.1 and 20.0.2 all of which encountered errors. 20.0.2 is the same version of pip installed by default in focal. It should be ok to use this version of pip in a virtualenv for kubernetes-control-plane since layer-basic performs an upgrade on pip in the event it doesn't downgrade the current series installation of pip.