The pip3 role installs the latest upstream pip, overwriting the
packaged versions. We would prefer to install things in
venv/virtualenvs moving forward to keep better isolation.
Unfortunately thanks to time the Bionic era packaged pip is so old
that it can't install anything modern like Ansible. Thus we have to
squash installing Ansible into a separate venv into this change as
well.
Although the venv created by default on the Bionic host also has an
old pip, luckily we already worked around that in
I81fd268a9354685496a75e33a6f038a32b686352 which provides a create-venv
role that creates a fully updated venv for us.
To minimise other changes, this symlinks ansible/ansible-playbook into
/usr/local/bin. On our current production bastion host this will make
a bit of a mess -- but we are looking at replacing that with a fresh
system soon. The idea is that this new system will not be
bootstrapped with a globally installed Ansible, so we won't have
things lying around in multiple places.
Change-Id: I7551eb92bb6dc5918c367cc347f046ff562eab0c
7e9229c86d