Re: [tosca-comment] TOSCA for Kubernetes Resources

[Tal Liron <tliron@redhat.com>]

Hi Matej,

It doesn't seem likely that OASIS TOSCA would arbitrate this matter. The community repository is open to profile contributions, but none of these are OASIS standards. Indeed several Kubernetes profiles may be contributed. After a somewhat negative experience with managing the Simple Profile, the TOSCA TC has decided that profile development should best be left to the community. That said, nothing is stopping the community from embracing a "de facto standard" if a certain profile or combination becomes widely used and supported.

Compare this to the experience with programming languages. Though all programming languages come with a basic standard library, multiple open source solutions may exist for the same problem, each with its own subjective advantages. An obvious example is logging: I don't know of a programming language with just one logging API, even if the standard library includes logging.

We obviously care about portability but not at all costs. Each orchestrator that supports TOSCA is its own product with its own design paradigms and may have different assumptions and requirements for modeling. For example, Turandot works entirely differently from Cloudify and it's hard to imagine a Kubernetes profile that could be trivially consumed by both.

That said, in some cases it shouldn't be necessary to reinvent the wheel. The Kubernetes API is published and well-annotated, so it's deterministic to convert it to TOSCA. With Turandot I've included a profile generator (work in progress) that does exactly that. I know that Chris has something similar in Ubicity.

On Fri, Apr 8, 2022 at 7:29 AM Matej Feder <matej.feder@dnation.cloud> wrote:

Dear TOSCA community,

With this email, I would like to ask you what is the state-of-the-art for TOSCA-based application deployment to the Kubernetes environment.

In other words, I would like to define the TOSCA template for the Kubernetes resources ( Kubernetes Deployments, Kubernetes Configmaps, and so on) based on publicly available TOSCA types.

I went through a couple of opensource projects like:

- Turandot

- Cloudify

- MiCADO

- Indigo

and, it seems that each project defined its own TOSCA Types for Kubernetes resources.

My question is:

Is there any standardized way how to describe Kubernetes resources by TOSCA?

Thanks in advance for your help.

Regards,

Matej Feder

DevOps Engineer at dNation