Generate CRD in Go code

[chinglinwen]

CRD in Go code

I'd like to have crd write in go, and create crd when main.go runs, similar to this approach: https://github1s.com/k3s-io/helm-controller/blob/master/pkg/crd/crds.go

package crd

import (
	v1 "github.com/k3s-io/helm-controller/pkg/apis/helm.cattle.io/v1"
	"github.com/rancher/wrangler/v3/pkg/crd"
)

func List() []crd.CRD {
	chart := crd.NamespacedType("HelmChart.helm.cattle.io/v1").
		WithSchemaFromStruct(v1.HelmChart{}).
		WithColumn("Job", ".status.jobName").
		WithColumn("Chart", ".spec.chart").
		WithColumn("TargetNamespace", ".spec.targetNamespace").
		WithColumn("Version", ".spec.version").
		WithColumn("Repo", ".spec.repo").
		WithColumn("HelmVersion", ".spec.helmVersion").
		WithColumn("Bootstrap", ".spec.bootstrap").
		WithStatus()

	config := crd.NamespacedType("HelmChartConfig.helm.cattle.io/v1").
		WithSchemaFromStruct(v1.HelmChartConfig{})

	return []crd.CRD{chart, config}
}

https://github1s.com/k3s-io/helm-controller/blob/master/main.go#L60-L61

	ctx := cmd.Context()
	if err := wcrd.Create(ctx, clientConfig, crd.List()); err != nil {
		return err
	}

https://pkg.go.dev/github.com/rancher/wrangler/v3/pkg/crd

https://github.com/rancher/wrangler/blob/v3.1.0/pkg/crd/print.go#L57-L64

func Create(ctx context.Context, cfg *rest.Config, crds []CRD) error {
	factory, err := NewFactoryFromClient(cfg)
	if err != nil {
		return err
	}

	return factory.BatchCreateCRDs(ctx, crds...).BatchWait()
}

this way, it can be a lot simpler with a single deployment resource to apply.

would like kubebuilder to scaffold to generate such go file, and glue by main.go
say a file sit aside with types.go, maybe name: ${types}_crd_generated.go

[sbueringer]

This seems like a simple builder on top of the crd go type?

[chinglinwen]

this is just a example, I'd wish controller-gen can generated crd glue code in Go( so I can create crd when main.go started), rather than a bunch of yamls files.

[JoelSpeed]

You could embed the yaml file into the binary using a Go embedded FS, and marshal that into a CRD concrete type in your main.go, without any modification of how controller-tools works today