Find image repository retention solution

[trslater]

Our images are built in GitHub and not in OpenShift, so OpenShift retention policies don't work. We'll need to find another solution to automate pruning old images.

Purpose

• Avoid using too much space in image repository
• Avoid the need for manual intervention

Acceptance Criteria

• Figure out an automated solution to keep image repository usage down

Additional context

• Removing images is done by simply removing all the tags pointing to that image
• Challenges
  • The tags are all stored in the tools namespace, so it is impossible to know if an older tag is for dev, test, or prod environment.
    • If we try to keep only the most recent n images, they'll likely all be dev images
    • If we try to retain images by date, we may accidentally remove the current prod image, since prod is not deployed often
    • The current image tag for an environment can be found by looking in the deployment configs.
• My most recent thoughts on how to do this would be to:
  • Use an OpenShift cronjob
  • Remove based on date
  • Have an extra check for the currently deployed images for each environment and make sure to keep those