Fix e2e tests

Author: sbueringer

internal/controllers/topology/cluster/patches/engine.go

@@ -18,6 +18,7 @@ limitations under the License.
 package patches
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"runtime/debug"
@@ -464,12 +465,26 @@ func applyPatchToRequest(ctx context.Context, req *runtimehooksv1.GeneratePatche
 			return errors.Wrap(err, "failed to apply patch: error decoding json patch (RFC6902)")
 		}
 
+		if len(jsonPatch) == 0 {
+			// Return if there are no patches, nothing to do.
+			// If the requestItem.Object does not have a spec and we don't have a patch that adds one,
+			// patchTemplateSpec below would fail, so let's return early.
+			return nil
+		}
+
 		patchedTemplate, err = jsonPatch.Apply(requestItem.Object.Raw)
 		if err != nil {
 			log.Error(err, fmt.Sprintf("Failed to apply patch with uid %q: error applying json patch (RFC6902)", requestItem.UID), "patch", string(patch.Patch))
 			return errors.Wrap(err, "failed to apply patch: error applying json patch (RFC6902)")
 		}
 	case runtimehooksv1.JSONMergePatchType:
+		if len(patch.Patch) == 0 || bytes.Equal(patch.Patch, []byte("{}")) {
+			// Return if there are no patches, nothing to do.
+			// If the requestItem.Object does not have a spec and we don't have a patch that adds one,
+			// patchTemplateSpec below would fail, so let's return early.
+			return nil
+		}
+
 		log.V(5).Info("Accumulating JSON merge patch", "patch", string(patch.Patch))
 		patchedTemplate, err = jsonpatch.MergePatch(requestItem.Object.Raw, patch.Patch)
 		if err != nil {

internal/controllers/topology/cluster/patches/patch.go

@@ -195,7 +195,8 @@ func copySpec(in copySpecInput) error {
 	// Get spec from src.
 	srcSpec, found, err := unstructured.NestedFieldNoCopy(in.src.Object, strings.Split(in.srcSpecPath, ".")...)
 	if !found {
-		return errors.Errorf("missing field %q in %s %s", in.srcSpecPath, in.src.GetKind(), klog.KObj(in.src))
+		// Return if srcSpecPath does not exist in src, nothing to do.
+		return nil
 	} else if err != nil {
 		return errors.Wrapf(err, "failed to get field %q from %s %s", in.srcSpecPath, in.src.GetKind(), klog.KObj(in.src))
 	}

test/e2e/data/infrastructure-docker/main/bases/md.yaml

@@ -19,10 +19,6 @@ apiVersion: bootstrap.cluster.x-k8s.io/v1beta2
 kind: KubeadmConfigTemplate
 metadata:
   name: "${CLUSTER_NAME}-md-0"
-spec:
-  template:
-    spec:
-      joinConfiguration:
 ---
 # MachineDeployment object
 apiVersion: cluster.x-k8s.io/v1beta2

test/e2e/data/infrastructure-docker/main/bases/mp.yaml

@@ -42,5 +42,3 @@ apiVersion: bootstrap.cluster.x-k8s.io/v1beta2
 kind: KubeadmConfig
 metadata:
   name: "${CLUSTER_NAME}-mp-0-config"
-spec:
-  joinConfiguration:

test/e2e/data/infrastructure-docker/main/clusterclass-quick-start-runtimesdk.yaml

@@ -139,7 +139,3 @@ apiVersion: bootstrap.cluster.x-k8s.io/v1beta2
 kind: KubeadmConfigTemplate
 metadata:
   name: quick-start-default-worker-bootstraptemplate
-spec:
-  template:
-    spec:
-      joinConfiguration: