Implement json patches for manifests

Signed-off-by: alexander-demicev <[email protected]>

internal/controller/component_patches.go

@@ -0,0 +1,41 @@
+/*
+Copyright 2023 The Kubernetes 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 controller
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"sigs.k8s.io/cluster-api-operator/internal/controller/genericprovider"
+	"sigs.k8s.io/cluster-api-operator/internal/patch"
+	ctrl "sigs.k8s.io/controller-runtime"
+)
+
+func applyPatches(ctx context.Context, provider genericprovider.GenericProvider) func(objs []unstructured.Unstructured) ([]unstructured.Unstructured, error) {
+	log := ctrl.LoggerFrom(ctx)
+
+	return func(objs []unstructured.Unstructured) ([]unstructured.Unstructured, error) {
+		if len(provider.GetSpec().ManifestPatches) == 0 {
+			log.V(5).Info("No resource patches to apply")
+			return objs, nil
+		}
+
+		log.V(5).Info("Applying resource patches")
+
+		return patch.ApplyPatches(objs, provider.GetSpec().ManifestPatches)
+	}
+}

internal/controller/phases.go

@@ -419,8 +419,12 @@ func (p *phaseReconciler) fetch(ctx context.Context) (reconcile.Result, error) {
 
 	// ProviderSpec provides fields for customizing the provider deployment options.
 	// We can use clusterctl library to apply this customizations.
-	err = repository.AlterComponents(p.components, customizeObjectsFn(p.provider))
-	if err != nil {
+	if err := repository.AlterComponents(p.components, customizeObjectsFn(p.provider)); err != nil {
+		return reconcile.Result{}, wrapPhaseError(err, operatorv1.ComponentsFetchErrorReason)
+	}
+
+	// Apply patches to the provider components if specified.
+	if err := repository.AlterComponents(p.components, applyPatches(ctx, p.provider)); err != nil {
 		return reconcile.Result{}, wrapPhaseError(err, operatorv1.ComponentsFetchErrorReason)
 	}
 

internal/patch/matchinfo.go

@@ -0,0 +1,44 @@
+/*
+Copyright 2023 The Kubernetes 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 patch
+
+import (
+	"fmt"
+
+	"sigs.k8s.io/yaml"
+)
+
+// we match resources and patches on their v1 TypeMeta.
+type matchInfo struct {
+	Kind       string   `json:"kind,omitempty"`
+	APIVersion string   `json:"apiVersion,omitempty"`
+	Metadata   Metadata `json:"metadata,omitempty"`
+}
+
+type Metadata struct {
+	Name      string `json:"name,omitempty"`
+	Namespace string `json:"namespace,omitempty"`
+}
+
+func parseYAMLMatchInfo(raw []byte) (matchInfo, error) {
+	m := matchInfo{}
+	if err := yaml.Unmarshal(raw, &m); err != nil {
+		return matchInfo{}, fmt.Errorf("failed to parse match info: %w", err)
+	}
+
+	return m, nil
+}

internal/patch/mergepatch.go

@@ -0,0 +1,51 @@
+/*
+Copyright 2023 The Kubernetes 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 patch
+
+import (
+	"fmt"
+
+	"sigs.k8s.io/yaml"
+)
+
+type mergePatch struct {
+	json      []byte
+	matchInfo matchInfo
+}
+
+func parseMergePatches(rawPatches []string) ([]mergePatch, error) {
+	patches := []mergePatch{}
+
+	for _, patch := range rawPatches {
+		matchInfo, err := parseYAMLMatchInfo([]byte(patch))
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse patch: %w", err)
+		}
+
+		json, err := yaml.YAMLToJSON([]byte(patch))
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert YAML to JSON: %w", err)
+		}
+
+		patches = append(patches, mergePatch{
+			json:      json,
+			matchInfo: matchInfo,
+		})
+	}
+
+	return patches, nil
+}

internal/patch/patch.go

@@ -0,0 +1,68 @@
+/*
+Copyright 2023 The Kubernetes 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 patch
+
+import (
+	"fmt"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	utilyaml "sigs.k8s.io/cluster-api/util/yaml"
+	"sigs.k8s.io/yaml"
+)
+
+// ApplyPatches patches a list of unstructured objects with a list of patches.
+// Patches match if their kind and apiVersion match a document, with the exception
+// that if the patch does not set apiVersion it will be ignored.
+func ApplyPatches(toPatch []unstructured.Unstructured, patches []string) ([]unstructured.Unstructured, error) {
+	resources, err := parseResources(toPatch)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse resources: %w", err)
+	}
+
+	mergePatches, err := parseMergePatches(patches)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse patches: %w", err)
+	}
+
+	result := []unstructured.Unstructured{}
+
+	for _, r := range resources {
+		for _, p := range mergePatches {
+			if _, err := r.applyMergePatch(p); err != nil {
+				return nil, fmt.Errorf("failed to apply patch: %w", err)
+			}
+		}
+
+		r.patchedYAML, err = yaml.JSONToYAML(r.json)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse resource: %w", err)
+		}
+
+		patchedObj, err := utilyaml.ToUnstructured(r.patchedYAML)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse resource: %w", err)
+		}
+
+		if len(patchedObj) == 0 {
+			return nil, fmt.Errorf("patched object is empty")
+		}
+
+		result = append(result, patchedObj...)
+	}
+
+	return result, nil
+}