[nailgun] adding repository process inconsistency

[Maciej Relewicz]

Now we have two cases when we are adding repository to fuel:
- once using UI we put them to hiera (and this is a good and correct way)
- and other way, used when we are registering plugins, we put file with definition directly to repository directory (for ubuntu /etc/apt/sources.list.d (and this is bad)

Due to consistency and to provide enusurability for setup_repository.pp granular task, it should be fixed.

[Evgeniy L (rustyrobot)]

We should stop generating tasks with repo creation for OpenStack releases higher than 8.0, and add information about repositories right in deployment information.

Changelog/Documentation should be fixed accordingly and announcement about the change should be sent to openstack-dev.

[Ihor Kalnytskyi (ikalnytskyi)]

The issue is more complex than it looks like. If I'm not mistake the reason behind having a separate pre-deployment task for adding plugin's repos is to ensure they are available as early as possible. Consider the following example:

* Plugin add a deployment task that must be executed before any other task, and needs to install plugin package.
* By that time, we sure won't have any repos because "setup_repositories" wasn't executed yet.

Deployment simply will fail. I think there could be quite a number of plugins that installs something before "setup_repositories" is completed. I believe first of all we need to send an announcement to openstack-dev, about upcoming change. Then, I'd prefer to fix that bug in 10.0 and do not break experience in 9.0 - It's too late for that.

Regarding design.. we can insert a hack into deployment serializers that injects plugins' repos to the end of "repo_setup" list (where other repos are gathered) but it seems not cool solution now. I think it'd be much easier to implement if start making *layering* system similar to one we have with deployment task (but it's another story).

So what do you think, guys? Having an "injecting" hack in Nailgun is ok for you?

[Ihor Kalnytskyi (ikalnytskyi)]

(move ticket to 10.0, since it's not a bug and tech-debt and it's too late to change UX in 9.0)

[Evgeniy L (rustyrobot)]

If all repositories will be created by a single task, it will be hard to turn it off, or replace core repository creation without breaking other plugins. But consistency definitely makes sense.