In order to radically simplify how we prepare the service
venvs, we use a common role to do the wheel builds and the
venv preparation. This makes the process far simpler to
understand, because the role does its own building and
installing. It also reduces the code maintenance burden,
because instead of duplicating the build processes in the
repo_build role and the service role - we only have it all
done in a single place.
We also change the role venv tag var to use the integrated
build's common venv tag so that we can remove the role's
venv tag in group_vars in the integrated build. This reduces
memory consumption and also reduces the duplication.
This is by no means the final stop in the simplification
process, but it is a step forward. The will be work to follow
which:
1. Replaces 'developer mode' with an equivalent mechanism
that uses the common role and is simpler to understand.
We will also simplify the provisioning of pip install
arguments when doing this.
2. Simplifies the installation of optional pip packages.
Right now it's more complicated than it needs to be due
to us needing to keep the py_pkgs plugin working in the
integrated build.
3. Deduplicates the distro package installs. Right now the
role installs the distro packages twice - just before
building the venv, and during the python_venv_build role
execution.
Depends-On: https://review.openstack.org/598957
Change-Id: I1c1dcd73c9d5d78c0a8e40149ff84cbba828f3e2
Implements: blueprint python-build-install-simplification
Signed-off-by: Jesse Pretorius <jesse.pretorius@rackspace.co.uk>
b0241f8100