Argo CD 3.1 brings OCI support

Argo CD version 3.1 finally brings OCI support for generic manifests.

Argo CD already had OCI support for Helm charts (which actually was a Helm feature). Now it supports OCI for generic Kubernetes manifests.
Flux, on the other hand, has had this for years.

To use it, you just push your manifests (typical YAML files containing, deployments, services, ingresss, etc.) into an OCI registry using CLI like oras.

oras push <registry-url>/guestbook:latest .

The argo cd side within the Application stays almost the same, except that you’ll use an oci:// URL as repoUrl and likely a repo digest (sha256:...) as targerRevision.
See docs, video.

This works well with the rendered manifest pattern where you would hydrate your templates or overlays using helm or kustomize on your CI server.

For people using workflows based on pull requests, using OCI likely is not a useful addition. However, the use cases for reconciling manifests against OCI are environments where no git server is present (or not reachable due to network constraints). An OCI registry, on the other hand, has to be present for images and maybe helm charts as well.
If performance is an issue, an OCI registry works more efficiently than Git. As Alexis Richardson put it, the registry acts as GitOps Cache.

So from now on users of Argo CD also have the option of storing their manifests there. It’s great to see Argo CD catching up and allowing for using the commodity of OCI registry for GitOps reconciliation.