Architecture: Generic, template-able resource reconciler (Espejote)

[DebakelOrakel]

No description provided.

[tobru]

It would be great to see the option "Crossplane Composition (Functions)" discussed in the decision document. This technology could probably also solve the problem at hand. I don't want to say it's the best solution, but at least I'd like to see a discussion around it and a conscious decision why not to use it. Some references to learn more: https://docs.crossplane.io/v1.18/concepts/compositions/ "Compositions are a template for creating multiple managed resources as a single object."

[DebakelOrakel]

I don't see how Crossplane Compositions would be the proper tool for this task.
Also Option 1 discusses using existing tools.

[tobru]

Also Option 1 discusses using existing tools.

Option 1 discusses policy tools, Crossplane isn't one of them.

I don't see how Crossplane Compositions would be the proper tool for this task.

This is fine, but I want to understand the "why". Crossplane Compositions is exactly that, a template engine which reconciles resources.

This document which is being written serves as a decision document to look back in the future and understand why something was done in a certain way, what alternatives were out there and why they haven't been chosen.

[bastjan]

I'll add an option for the 737-MAX 👍

Edit:

For only 490 objects:

❯ ka get apirequestcounts.apiserver.openshift.io objects.v1alpha2.kubernetes.crossplane.io 
NAME                                        REMOVEDINRELEASE   REQUESTSINCURRENTHOUR   REQUESTSINLAST24H
objects.v1alpha2.kubernetes.crossplane.io                      108573                  2729970

We tried very very hard to minimize the footgun potential in the architecture of espejote.

[DebakelOrakel]

Option 1 discusses policy tools, Crossplane isn't one of them.

That is true, the conclusion still remains.

• Crossplane is primarly designed to manage external infrastructure resources.
• Using a full-blown control-plane solution just to do something that a very simple operator can do much more efficiently.
• Instead of using technology we already use (Jsonnet) we would need to learn a very complex framework for a simple task.

Above points are the reason why we never considered using Crossplane, bc it never was a reasonable choice to consider given the problem statement.

[simu]

Decision LGTM. Architecture LGTM overall, some comments inline.

[haasad]

Kyverno generate policies have a synchronize property that allows you to choose not to sync a resource after it was created. Could something similar be done with espejote?