flux2-multi-tenancy VS argocd-image-updater

You may look at multi tenant deployment of fluxcd at https://github.com/fluxcd/flux2-multi-tenancy where you can have shared infrastructure repo to bootstrap flux with terraform (if you wish) and then a repo per team to manage k8s resources.

Bootstrap Flux v2 to the cluster via Gitlab CI then deploy everything else using their multi tenant approach - https://github.com/fluxcd/flux2-multi-tenancy

We are exploring this GitOps trend at Playtomic. We have two k8s clusters running using Flux and ArgoCD. We have a multi-tenancy setup, that is, one repo for the cluster itself, one repo for every application we deploy in the cluster. Flux and ArgoCD image updaters are in place.

Maybe this is helpful https://github.com/fluxcd/flux2-multi-tenancy

Use the ArgoCD image updater

We already have software agents in GitOps ecosystem that modify the state in git. Ie, the image updater in ArgoCD. It watches the docker registry. When it sees a new image, it updates git on a user's behalf.

If you are using ArgoCD you might be able to use this: https://argocd-image-updater.readthedocs.io/en/stable/

I just found this in my travels, I have only gone so far as reading the introduction but seems to be a fit? https://github.com/argoproj-labs/argocd-image-updater

I've used Keel and more recently ArgoCD Image Updater (Using ArgoCD to manage deployments).

https://argocd-image-updater.readthedocs.io/en/stable/ maybe?

Use the image updater

To answer your question you should promote docker images between environments. There are many ways to do this. Check https://argocd-image-updater.readthedocs.io/en/stable/ if you haven't seen it already.

For ArgoCD there’s argocd-image-updated, https://argocd-image-updater.readthedocs.io/en/stable/