add logic to apiresourceschema ctrl to maintain a matching APIConversion object in kcp

On-behalf-of: @SAP [email protected]

Author: xrstf

internal/controller/apiresourceschema/controller.go

@@ -28,6 +28,7 @@ import (
 	"github.com/kcp-dev/api-syncagent/internal/crypto"
 	"github.com/kcp-dev/api-syncagent/internal/discovery"
 	"github.com/kcp-dev/api-syncagent/internal/projection"
+	"github.com/kcp-dev/api-syncagent/internal/resources/reconciling"
 	syncagentv1alpha1 "github.com/kcp-dev/api-syncagent/sdk/apis/syncagent/v1alpha1"
 
 	kcpdevv1alpha1 "github.com/kcp-dev/kcp/sdk/apis/apis/v1alpha1"
@@ -135,16 +136,28 @@ func (r *Reconciler) reconcile(ctx context.Context, log *zap.SugaredLogger, pubR
 	}
 
 	// project the CRD (i.e. strip unwanted versions, rename values etc.)
-	projectedCRD, err := projection.ApplyProjection(crd, pubResource)
+	projectedCRD, err := projection.ProjectCRD(crd, pubResource)
 	if err != nil {
 		return nil, fmt.Errorf("failed to apply projection rules: %w", err)
 	}
 
 	// generate a unique name for this exact state of the CRD
 	arsName := r.getAPIResourceSchemaName(projectedCRD)
+	wsCtx := kontext.WithCluster(ctx, r.lcName)
+
+	projectedConversions, err := projection.ProjectConversionRules(pubResource)
+	if err != nil {
+		return nil, fmt.Errorf("failed to apply projection rules to conversions: %w", err)
+	}
+
+	// only reconcile if there are rules because APIConversions must contain at least one conversion
+	if len(projectedConversions) > 0 {
+		if err := r.reconcileConversions(wsCtx, arsName, projectedConversions); err != nil {
+			return nil, fmt.Errorf("failed to reconcile APIConversions: %w", err)
+		}
+	}
 
 	// ensure ARS exists (don't try to reconcile it, it's basically entirely immutable)
-	wsCtx := kontext.WithCluster(ctx, r.lcName)
 	ars := &kcpdevv1alpha1.APIResourceSchema{}
 	err = r.kcpClient.Get(wsCtx, types.NamespacedName{Name: arsName}, ars, &ctrlruntimeclient.GetOptions{})
 
@@ -169,6 +182,8 @@ func (r *Reconciler) reconcile(ctx context.Context, log *zap.SugaredLogger, pubR
 		}
 	}
 
+	// reconcile a matching APIConversion object
+
 	return nil, nil
 }
 
@@ -206,3 +221,11 @@ func (r *Reconciler) getAPIResourceSchemaName(crd *apiextensionsv1.CustomResourc
 	// include a leading "v" to prevent SHA-1 hashes with digits to break the name
 	return fmt.Sprintf("v%s.%s.%s", checksum[:8], crd.Spec.Names.Plural, crd.Spec.Group)
 }
+
+func (r *Reconciler) reconcileConversions(ctx context.Context, arsName string, rules []kcpdevv1alpha1.APIVersionConversion) error {
+	factories := []reconciling.NamedAPIConversionReconcilerFactory{
+		r.createAPIConversionReconciler(arsName, r.agentName, rules),
+	}
+
+	return reconciling.ReconcileAPIConversions(ctx, factories, "", r.kcpClient)
+}

internal/controller/apiresourceschema/reconciler.go

@@ -0,0 +1,42 @@
+/*
+Copyright 2025 The KCP Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package apiresourceschema
+
+import (
+	"github.com/kcp-dev/api-syncagent/internal/resources/reconciling"
+	syncagentv1alpha1 "github.com/kcp-dev/api-syncagent/sdk/apis/syncagent/v1alpha1"
+
+	kcpapisv1alpha1 "github.com/kcp-dev/kcp/sdk/apis/apis/v1alpha1"
+	kcpdevv1alpha1 "github.com/kcp-dev/kcp/sdk/apis/apis/v1alpha1"
+)
+
+func (r *Reconciler) createAPIConversionReconciler(name string, agentName string, rules []kcpapisv1alpha1.APIVersionConversion) reconciling.NamedAPIConversionReconcilerFactory {
+	return func() (string, reconciling.APIConversionReconciler) {
+		return name, func(existing *kcpdevv1alpha1.APIConversion) (*kcpdevv1alpha1.APIConversion, error) {
+			if existing.Annotations == nil {
+				existing.Annotations = map[string]string{}
+			}
+			existing.Annotations[syncagentv1alpha1.AgentNameAnnotation] = agentName
+
+			existing.Spec = kcpdevv1alpha1.APIConversionSpec{
+				Conversions: rules,
+			}
+
+			return existing, nil
+		}
+	}
+}

internal/projection/projection.go

@@ -24,6 +24,8 @@ import (
 
 	syncagentv1alpha1 "github.com/kcp-dev/api-syncagent/sdk/apis/syncagent/v1alpha1"
 
+	kcpapisv1alpha1 "github.com/kcp-dev/kcp/sdk/apis/apis/v1alpha1"
+
 	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/util/sets"
@@ -67,7 +69,7 @@ func getStorageVersion(crd *apiextensionsv1.CustomResourceDefinition) string {
 // PublishedResourceProjectedGVK returns the effective GVK after the projection
 // rules have been applied according to the PublishedResource.
 func PublishedResourceProjectedGVK(originalCRD *apiextensionsv1.CustomResourceDefinition, pubRes *syncagentv1alpha1.PublishedResource) (schema.GroupVersionKind, error) {
-	projectedCRD, err := ApplyProjection(originalCRD, pubRes)
+	projectedCRD, err := ProjectCRD(originalCRD, pubRes)
 	if err != nil {
 		return schema.GroupVersionKind{}, fmt.Errorf("failed to project CRD: %w", err)
 	}
@@ -84,7 +86,7 @@ func PublishedResourceProjectedGVK(originalCRD *apiextensionsv1.CustomResourceDe
 	}, nil
 }
 
-func ApplyProjection(crd *apiextensionsv1.CustomResourceDefinition, pubRes *syncagentv1alpha1.PublishedResource) (*apiextensionsv1.CustomResourceDefinition, error) {
+func ProjectCRD(crd *apiextensionsv1.CustomResourceDefinition, pubRes *syncagentv1alpha1.PublishedResource) (*apiextensionsv1.CustomResourceDefinition, error) {
 	result := crd.DeepCopy()
 
 	// reduce the CRD down to the selected versions
@@ -100,7 +102,7 @@ func ApplyProjection(crd *apiextensionsv1.CustomResourceDefinition, pubRes *sync
 	}
 
 	// now we get to actually project something, if desired
-	result, err = projectCRD(result, pubRes)
+	result, err = projectCRDNames(result, pubRes)
 	if err != nil {
 		return nil, err
 	}
@@ -168,7 +170,7 @@ func adjustStorageVersion(crd *apiextensionsv1.CustomResourceDefinition) (*apiex
 	return crd, nil
 }
 
-func projectCRD(crd *apiextensionsv1.CustomResourceDefinition, pubRes *syncagentv1alpha1.PublishedResource) (*apiextensionsv1.CustomResourceDefinition, error) {
+func projectCRDNames(crd *apiextensionsv1.CustomResourceDefinition, pubRes *syncagentv1alpha1.PublishedResource) (*apiextensionsv1.CustomResourceDefinition, error) {
 	projection := pubRes.Spec.Projection
 	if projection == nil {
 		return crd, nil
@@ -237,3 +239,22 @@ func projectCRD(crd *apiextensionsv1.CustomResourceDefinition, pubRes *syncagent
 
 	return crd, nil
 }
+
+func ProjectConversionRules(pubRes *syncagentv1alpha1.PublishedResource) ([]kcpapisv1alpha1.APIVersionConversion, error) {
+	result := pubRes.DeepCopy().Spec.Conversions
+
+	if proj := pubRes.Spec.Projection; proj != nil {
+		for idx, conversion := range result {
+			if projectedFrom := proj.Versions[conversion.From]; projectedFrom != "" {
+				conversion.From = projectedFrom
+			}
+			if projectedTo := proj.Versions[conversion.To]; projectedTo != "" {
+				conversion.To = projectedTo
+			}
+
+			result[idx] = conversion
+		}
+	}
+
+	return result, nil
+}