[codegen] Add Webhook Conversion Strategy to Generated CRDs

[IfSentient]

Add extra optional webhook conversion params to apiResource in CUE kind, use those parameters to add webhook conversion strategy to generated CRD's when apiResource.conversion = true.

The extra parameters are a temporary measure as we move toward the codegen having a manifest to look at which would include the necessary information.

[radiohead]

We need to support url (https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.30/#webhookclientconfig-v1-apiextensions-k8s-io) here, either as an option, or as the main & only way – we don't use service configs at all.

[IfSentient]

I'll change it to the main & only way, as this is something we'll likely want to address better in the manifest and this is a temporary patch.

[radiohead]

SGTM!

There's an issue with the code at the moment, since it doesn't comply with CRD schema – the config should be either a Service or an URL.

I suggest that instead of hand-rolling custom types, we instead use the canonical ones from upstream, e.g. something like this:

diff --git a/codegen/jennies/crd.go b/codegen/jennies/crd.go
index 17c5f91..32ad450 100644
--- a/codegen/jennies/crd.go
+++ b/codegen/jennies/crd.go
@@ -3,11 +3,13 @@ package jennies
 
 import (
 	"fmt"
+	"net/url"
 	"strings"
 
 	"cuelang.org/go/cue"
 	"github.com/grafana/codejen"
 	goyaml "gopkg.in/yaml.v3"
+	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 
 	"github.com/grafana/grafana-app-sdk/codegen"
 	"github.com/grafana/grafana-app-sdk/k8s"
@@ -53,15 +55,18 @@ func (c *crdGenerator) Generate(kind codegen.Kind) (*codejen.File, error) {
 	}
 
 	if kind.Properties().APIResource.Conversion {
-		resource.Spec.Conversion = &k8s.CustomResourceDefinitionSpecConversion{
-			Strategy: "webhook",
-			Webhook: &k8s.CustomResourceDefinitionSpecConversionWebhook{
+		u := kind.Properties().APIResource.ConversionWebhookProps.URL
+
+		if _, err := url.Parse(u); err != nil {
+			return nil, err
+		}
+
+		resource.Spec.Conversion = &apiextensionsv1.CustomResourceConversion{
+			Strategy: apiextensionsv1.WebhookConverter,
+			Webhook: &apiextensionsv1.WebhookConversion{
 				ConversionReviewVersions: []string{"v1"},
-				ClientConfig: k8s.CustomResourceDefinitionClientConfig{
-					Service: k8s.CustomResourceDefinitionClientConfigService{
-						Path: kind.Properties().APIResource.ConversionWebhookProps.Path,
-						URL:  kind.Properties().APIResource.ConversionWebhookProps.URL,
-					},
+				ClientConfig: &apiextensionsv1.WebhookClientConfig{
+					URL: &u,
 				},
 			},
 		}
diff --git a/k8s/manager.go b/k8s/manager.go
index 4cabd17..cf6a4c3 100644
--- a/k8s/manager.go
+++ b/k8s/manager.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	kschema "k8s.io/apimachinery/pkg/runtime/schema"
@@ -324,32 +325,11 @@ func (crd *CustomResourceDefinition) DeepCopyObject() runtime.Object {
 
 // CustomResourceDefinitionSpec is the body or spec of a kubernetes Custom Resource Definition
 type CustomResourceDefinitionSpec struct {
-	Group      string                                  `json:"group" yaml:"group"`
-	Versions   []CustomResourceDefinitionSpecVersion   `json:"versions" yaml:"versions"`
-	Names      CustomResourceDefinitionSpecNames       `json:"names" yaml:"names"`
-	Conversion *CustomResourceDefinitionSpecConversion `json:"conversion,omitempty" yaml:"conversion,omitempty"`
-	Scope      string                                  `json:"scope" yaml:"scope"`
-}
-
-type CustomResourceDefinitionSpecConversion struct {
-	Strategy string                                         `json:"strategy" yaml:"strategy"`
-	Webhook  *CustomResourceDefinitionSpecConversionWebhook `json:"webhook,omitempty" yaml:"webhook,omitempty"`
-}
-
-type CustomResourceDefinitionSpecConversionWebhook struct {
-	ConversionReviewVersions []string                             `json:"conversionReviewVersions" yaml:"conversionReviewVersions"`
-	ClientConfig             CustomResourceDefinitionClientConfig `json:"clientConfig" yaml:"clientConfig"`
-}
-
-type CustomResourceDefinitionClientConfig struct {
-	Service CustomResourceDefinitionClientConfigService `json:"service" yaml:"service"`
-}
-
-type CustomResourceDefinitionClientConfigService struct {
-	URL       string `json:"url,omitempty" yaml:"url,omitempty"`
-	Name      string `json:"name,omitempty" yaml:"name,omitempty"`
-	Namespace string `json:"namespace,omitempty" yaml:"namespace,omitempty"`
-	Path      string `json:"path" yaml:"path"`
+	Group      string                                    `json:"group" yaml:"group"`
+	Versions   []CustomResourceDefinitionSpecVersion     `json:"versions" yaml:"versions"`
+	Names      CustomResourceDefinitionSpecNames         `json:"names" yaml:"names"`
+	Conversion *apiextensionsv1.CustomResourceConversion `json:"conversion,omitempty" yaml:"conversion,omitempty"`
+	Scope      string                                    `json:"scope" yaml:"scope"`
 }
 
 // CustomResourceDefinitionSpecVersion is the representation of a specific version of a CRD, as part of the overall spec

(I've also thrown in URL validation but feel free to drop it).

[IfSentient]

Sorry, this comment totally slipped through the cracks for me, just noticed it today. The problem with using the kubernetes types is that they don't have yaml tags, which presented problems in the past for YAML marshal (which is why the SDK has ones which are hand-rolled). I can fix the structure, though.

[IfSentient]

@radiohead fixed the URL portion, I think we can move over to using the k8s types if we change our YAML library, I'll try to get that working in a different PR.