Investigate `kind` replacement for e2e about descheduler

[BenTheElder]

For K/K we're fetching kind from HEAD to stay compatible with any kubernetes breaking changes, but we're also running equivalent CI jobs, it's possible we'd have a breaking change that you'd have found in the release notes.

That said, we're avoiding those as much as possible, and when we're planning one they've generally been pre-announced (like the containerd 2.0 style registry config) in previous release notes similar to Kubernetes style deprecations. This isn't always possible when we have to react to e.g. the runc misc cgroup changes but generally speaking upgrading to those changes should be desired in a typical CI environment.

We're discussing continuous image builds in the future, right now we build releases with https://github.com/kubernetes-sigs/kind/blob/0a7403e49c529d22cacd3a3f3606b9d8a5c16ae7/hack/release/build/push-node.sh which amongst other things is making the images smaller by compiling out dockershim and cloud providers ... which won't be necessary vs standard builds in 1.31+

[BenTheElder]

As an upstream kubernetes project you should really consider testing against upcoming Kubernetes before it releases, by doing kind build node image within the e2e pipeline and then kind create cluster --image=kindest/node:latest (from the locally built image, more in the docs).

EDIT: 1.30 is out anyhow.

[a7i]

cc: @pravarag since you wanted to look into this.

I think we could do something like:

docker pull kindest/node:v1.30.0 || build_kind_image_from_source

[damemi]

Thanks @BenTheElder, that's a great suggestion and I think it's exactly what we've been looking for. It has always felt a bit weird that we were dependent on waiting until after the kind release to test and publish our next release. I didn't know about that option

[damemi]

@a7i I'd say our master branch could always be building from source, with our tag branches using the released version

The downside to that is we run the risk of getting master blocked on bugs from kind though

[a7i]

Wouldn't that still get us blocked on kind image being released? Unless that's intentional?

[damemi]

It would block new PRs to the tagged branch until that image was available, so maybe the release branches could use the conditional switch like you're suggesting