Consider integration with Flux via a "Ytt Controller"

[ThomasVitale]

Describe the problem/challenge you have
I really like working with ytt and I usually use it together with kapp-controller. Still, I'm afraid many organisations might miss out on the great power of ytt because of the challenge to integrate it in their already-established GitOps workflow based on Flux. And that would limit a wider adoption of ytt.

Describe the solution you'd like
Flux is based on highly modular toolkit. In particular, the Source Controller provides support for different types of artefacts (Git, OCI, buckets), the Kustomize Controller provides support for Kustomize-based deployments, and Helm Controller for helm releases. Perhaps it could be an idea to introduce a Ytt Controller component in the GitOps Toolkit used by Flux. What do you think?

Anything else you would like to add:
In a recent community meeting, there was a conversation around integration possibilities with Flux and some of the resulting ideas are gathered in carvel-dev/kapp-controller#1048.

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This issue is being marked as stale due to a long period of inactivity and will be closed in 5 days if there is no response.

[ThomasVitale]

Dear bot, please keep the issue open :)

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This issue is being marked as stale due to a long period of inactivity and will be closed in 5 days if there is no response.

[100mik]

Thanks to Praveen for valiantly fighting off the bot, I am going to add a discussion tag here so that it so that we can have a truce 😆

[100mik]

I think it would be interesting to compare the pros and cons of having fine grained controllers vs having a "use flux to deploy a Carvel package" controller.
Maybe this is something we should bring up in the next community meeting and then summarise here 🤔

[ThomasVitale]

@100mik this is the community Ytt Controller I mentioned earlier that makes it possible to use ytt with Flux: https://projectsveltos.github.io/sveltos/ytt_extension/ Project: https://github.com/gianlucam76/ytt-controller

It works as a post-processor outside Flux. What I had in mind was a native ytt controller built using the GitOps Toolkit provided by the Flux project (similar to how the kustomize and helm controllers work).

[100mik]

Would this mean we would contribute these bits to the Flux project directly?

[warroyo]

this would be a great addition to natively support in carvel. I recently created a similar issue here.

this would not be a contribution to the flux project but rather a carvel maintained controller that could reference flux objects. just like the community project mentioned above.

I would like to see both the kapp integration and the ytt controller make it into official carvel features