Support OCI manifests

[joebowbeer]

Checklist

• [x] I've searched the issue queue to verify this is not a duplicate feature request.

Proposed Feature

Kargo should be able to use OCI registries for k8s manifests.

This includes the ability for a stage to subscribe to manifests from an OCI registry as well as to publish rendered manifests to an OCI registry.

Motivation

In the rendered manifest pattern, the rendered manifests are artifacts and, as such, should be published to an OCI registry (e.g., ghcr).

In addition, OCI registries support signed manifests.

Suggested Implementation

ArgoCD is adding first-class support for OCI

https://github.com/argoproj/argo-cd/blob/master/docs/proposals/native-oci-support.md

Flux already supports OCI. The flux cli can push/pull manifests to/from OCI registries.

https://fluxcd.io/flux/cheatsheets/oci-artifacts/

[krancour]

Thanks for an interesting idea @joebowbeer. I think there's a lot to work through here, but I really like the idea.

[github-actions[bot]]

This issue has been automatically marked as stale because it had no activity for 90 days. It will be closed if no activity occurs in the next 30 days but can be reopened if it becomes relevant again.

[krancour]

Not stale.

[github-actions[bot]]

This issue has been automatically marked as stale because it had no activity for 90 days. It will be closed if no activity occurs in the next 30 days but can be reopened if it becomes relevant again.

[hoopty]

The Argo CD link is https://github.com/argoproj/argo-cd/blob/master/docs/proposals/native-oci-support.md

[blakepettersson]

Something being worked on atm with argoproj/argo-cd#18646