[FEATURE] Config file compatible with Kustomize

[erikgb]

Is your feature request related to a problem or a Pull Request

No

Scope of your request

We use kustomize for kustomizing K8s resources, but also for other related declarative configuration that is K8s'ish, like kuttl TestSuite. I tried to do the same with our k3d config files without success.

There is an old Kustomize issue, that actually got worse in later versions of Kustomize, requiring all Kustomize resources to have a metadata.name property, and there seems to be no workaround at present. Trying to add metadata.name to the k3d config-file results in the following error: FATA[0000] Schema Validation failed for config file k3d-config.yml: - (root): Additional property metadata is not allowed , which makes a lot of sense.

To mend this, I would like to "please" kustomize and somehow allow metadata.name to be included in k3d config-files.

Describe the solution you'd like

What I suggest, is to move the existing name property to metadata.name in the k3d-config file format. It will definitely be a breaking change, but since the configuration is already versioned K8s'ish with apiVersion , this could work out.

So:

apiVersion: k3d.io/v1alpha4
kind: Simple
metadata:
  name: mycluster

instead of

apiVersion: k3d.io/v1alpha3
kind: Simple
name: mycluster

Describe alternatives you've considered

• Hope/help Kustomize to fix Kustomize doesn't support metadata.generateName kubernetes-sigs/kustomize#641, but I would not expect that to happen soon.
• Apply a JSON 6902 patch moving metadata.name to name in the last layer of my kustomization, but that does not work either. At least not in recent versions of Kustomize.

[iwilltry42]

Hi @erikgb , thanks for opening this issue!
As discussed via Slack, I introduced v1alpha4 now (see #944).
For adding this change yourself, you need to touch (at least) the following files:

• https://github.com/rancher/k3d/blob/main/pkg/config/v1alpha4/types.go#L139 : Add Metadata struct to SimpleConfig struct
• https://github.com/rancher/k3d/blob/main/pkg/config/v1alpha4/schema.json#L24-L28 : adjust schema accordingly
• https://github.com/rancher/k3d/blob/main/pkg/config/v1alpha4/migrations.go#L52-L56 : add a migration moving name (v1alpha3) to metadata.name (v1alpha4)

Let me know if you need any help :)

[erikgb]

Thanks a lot for the excellent directions @iwilltry42! 😍 Made this quite easy to do. Please have a look at the PR when you have time!

[gbonnefille]

Hi @erikgb

I'm really curious about the way you use the config file with kustomize. Is it with the template command to dump a file, or is there any other tooling around it to automatically create a local cluster?

Thanks in advance for any advice.