This patch ensures that if the local repo server has a copy of the
get-pip.py script then it will be used instead of reaching out to
the default location on the internet.
The tasks to set upper constraints are removed form the unbound
and repo-server playbooks as those roles do not execute any form
of pip installation.
This approach is taken to ensure that:
- Before the repo is built, the get-pip process in the pip_install
role still has two chances to fetch the get-pip.py script. If we
simply override the first URL option in group_vars then the
initial task will fail before the repo is built for the release
being executed and we would therefore only get one fallback.
- After the repo is built, if the lxc-host-setup and other pre-repo
playbooks are run, the plays will use the repo's get-pip script
instead of reaching upstream to fetch a fresh one. This maintains
a consistent get-pip script version within the same tag forever.
If group_vars are set for the targets of these plays to use the
upstream URL then the experience is not the same - the lxc_hosts
group will always get the latest upstream get-pip script every
time the playbook executes, resulting in the lxc hosts having a
different copy of the script to other hosts and containers.
Partial-Bug: #1633105
Depends-On: I3735ec50d51e10d0bc4a7f6677a800444fb33912
Depends-On: I4a2ff6c6e5cd40d87d4218f63c09e96da82da1aa
Change-Id: I9b558a14e800bb77d78021f665173dcdfaf2f4aa
47d3f8733f