Remove 'synchronization' phase

[europ]

This phase seems to be useless due to:

• labels are supported only for job templates (JT), so it is only possible to track job_templates
  • it fails if JT does not exist in a repository
  • it notifies if JT will be recreated
• if the asset does not exist, the differentiation phase can catch this case
  • https://github.com/europ/atacac/blob/master/atacac/differentiate.py#L23
  • the asset is supposed to be recreated
• it should be the developers responsibility to keep all assets in the repository

What should be modified?

• remove file synchronize.py
• remove function tower_list from _utils.py
• remove job synchronization from .TEMPLATE.gitlab-ci.yml
• remove related documentation in docs/README.md
• fix diagrams in docs/README.md

[amarza-rh]

This feature is aimed at projects that want to keep track of a large number of assets.

The use case is that there are untracked resources in Tower using the same label, which can happen when:

• People have added resources in Tower but not in git (fix is to add resources in git)
• Labels have been set incorrectly e.g. we're using someone else's labels (fix is to use different labels)
• Assets in Tower that should be deleted (determination is performed by a human; fix is to manually delete such resources)

The synchronization step ensures the state in Tower is as it should be in the config.

Additionally:

it should be the developers responsibility to keep all assets in the repository

The synchronization just ensure this is the case.

labels are supported only for job templates

This is the intended use case. Assets are linked to the project starting from the job/workflow templates. The project could be expanded to cater for Tower admins, but currently is not the case.

[amarza-rh]

@fpob can you comment here?