Story (Required)

• As a user of image-updater, I need to know how to authenticate to Azure Container Registry with workload identity.

Background and Approach (Required)

• many users are using image-updater with azure container registries, which commonly use workload identity as authentication mechanism.
• image-updater need to clearly document how to achieve the above task. There have been quite some communtiy discussions and suggestions on this. PR #676 should be able to address that for many use cases involving image-updater and azure container registry and workload identity.
• relevant community issues and PR:
  • https://github.com/argoproj-labs/argocd-image-updater/pull/676
  • https://github.com/argoproj-labs/argocd-image-updater/pull/586
  • https://github.com/argoproj-labs/argocd-image-updater/issues/550
  • https://github.com/argoproj-labs/argocd-image-updater/issues/473
  • https://github.com/argoproj-labs/argocd-image-updater/issues/1033 

Out of Scope

• docs for other auth mechanisms used by azure container registries
• docs for other authentication to other container registries

Dependencies

• none

Acceptance Criteria (Mandatory)

• clear docs on how to configure image-updater to successfully authenticate to azure container registries with workload identity.

Definition of Done

• Code Complete:
  • new sections in docs/configuration/registries.md are created
• Tested:
  • steps in new docs are verified by users
• Documentation:
  • relevant docs are created
• Build:
  • Code has been successfully built and integrated into the main repository / project.
• Review:
  • new sections in docs are reviewed and approved.
• Deployment:
  • N/A