Declare status.conditions on resources as associative list

[pedjak]

What problem are you facing?

Currently status.conditions is declared as atomic list, forcing us to provide always the whole list during updates. If we want to achieve no-op update, in cases when nothing changes, then the list must be in the same order, as the previous order.

How could Crossplane help solve your problem?

We should declare ``status.conditions` as an associate list. The schema defined in CRDs should include the following snippet:

properties:
  conditions:
  .
  .
    type: array
    x-kubernetes-list-map-keys:
    - type
    x-kubernetes-list-type: map

This change enables the following improvements:

• support for partial updates (server-side apply), lowering chances for conflicts
• owning of individual conditions
• reduced number of resource changes because no-op updates can be detected, leading to less reconciliations

[negz]

Agreed. I think we should do this for v1.14, since Composition Functions already use SSA. Cross-ref crossplane/upjet#300. I'll move this to crossplane-runtime since that's where these types live.

[negz]

Actually, my mistake. For Functions its XR status that's important and those are defined at https://github.com/crossplane/crossplane/blob/89b5fe534199b8571c5625f6f6829fcb676c010d/internal/xcrd/schemas.go#L332 so we should update that (as well as the types defined here).

[negz]

I think this was fixed by the above two PRs. 😄