Able to use this project components as golang library

Author: dmvolod

cmd/upgrade.go

@@ -2,7 +2,6 @@ package cmd
 
 import (
 	"bytes"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"log"
@@ -11,19 +10,9 @@ import (
 	"strconv"
 	"strings"
 
-	jsonpatch "github.com/evanphx/json-patch/v5"
-	jsoniterator "github.com/json-iterator/go"
 	"github.com/spf13/cobra"
 	"helm.sh/helm/v3/pkg/action"
 	"helm.sh/helm/v3/pkg/cli"
-	"helm.sh/helm/v3/pkg/kube"
-	apiextv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
-	apierrors "k8s.io/apimachinery/pkg/api/errors"
-	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/apimachinery/pkg/types"
-	"k8s.io/apimachinery/pkg/util/strategicpatch"
-	"k8s.io/cli-runtime/pkg/resource"
-	"sigs.k8s.io/yaml"
 
 	"github.com/databus23/helm-diff/v3/diff"
 	"github.com/databus23/helm-diff/v3/manifest"
@@ -117,7 +106,6 @@ perform.
 `
 
 var envSettings = cli.New()
-var yamlSeperator = []byte("\n---\n")
 
 func newChartCommand() *cobra.Command {
 	diff := diffCmd{
@@ -316,7 +304,7 @@ func (d *diffCmd) runHelm3() error {
 		if err != nil {
 			return fmt.Errorf("unable to build kubernetes objects from new release manifest: %w", err)
 		}
-		releaseManifest, installManifest, err = genManifest(original, target)
+		releaseManifest, installManifest, err = manifest.Generate(original, target)
 		if err != nil {
 			return fmt.Errorf("unable to generate manifests: %w", err)
 		}
@@ -354,216 +342,3 @@ func (d *diffCmd) runHelm3() error {
 
 	return nil
 }
-
-func genManifest(original, target kube.ResourceList) ([]byte, []byte, error) {
-	var err error
-	releaseManifest, installManifest := make([]byte, 0), make([]byte, 0)
-
-	// to be deleted
-	targetResources := make(map[string]bool)
-	for _, r := range target {
-		targetResources[objectKey(r)] = true
-	}
-	for _, r := range original {
-		if !targetResources[objectKey(r)] {
-			out, _ := yaml.Marshal(r.Object)
-			releaseManifest = append(releaseManifest, yamlSeperator...)
-			releaseManifest = append(releaseManifest, out...)
-		}
-	}
-
-	existingResources := make(map[string]bool)
-	for _, r := range original {
-		existingResources[objectKey(r)] = true
-	}
-
-	var toBeCreated kube.ResourceList
-	for _, r := range target {
-		if !existingResources[objectKey(r)] {
-			toBeCreated = append(toBeCreated, r)
-		}
-	}
-
-	toBeUpdated, err := existingResourceConflict(toBeCreated)
-	if err != nil {
-		return nil, nil, fmt.Errorf("rendered manifests contain a resource that already exists. Unable to continue with update: %w", err)
-	}
-
-	_ = toBeUpdated.Visit(func(r *resource.Info, err error) error {
-		if err != nil {
-			return err
-		}
-		original.Append(r)
-		return nil
-	})
-
-	err = target.Visit(func(info *resource.Info, err error) error {
-		if err != nil {
-			return err
-		}
-		kind := info.Mapping.GroupVersionKind.Kind
-
-		// Fetch the current object for the three way merge
-		helper := resource.NewHelper(info.Client, info.Mapping)
-		currentObj, err := helper.Get(info.Namespace, info.Name)
-		if err != nil {
-			if !apierrors.IsNotFound(err) {
-				return fmt.Errorf("could not get information about the resource: %w", err)
-			}
-			// to be created
-			out, _ := yaml.Marshal(info.Object)
-			installManifest = append(installManifest, yamlSeperator...)
-			installManifest = append(installManifest, out...)
-			return nil
-		}
-		// to be updated
-		out, _ := jsoniterator.ConfigCompatibleWithStandardLibrary.Marshal(currentObj)
-		pruneObj, err := deleteStatusAndTidyMetadata(out)
-		if err != nil {
-			return fmt.Errorf("prune current obj %q with kind %s: %w", info.Name, kind, err)
-		}
-		pruneOut, err := yaml.Marshal(pruneObj)
-		if err != nil {
-			return fmt.Errorf("prune current out %q with kind %s: %w", info.Name, kind, err)
-		}
-		releaseManifest = append(releaseManifest, yamlSeperator...)
-		releaseManifest = append(releaseManifest, pruneOut...)
-
-		originalInfo := original.Get(info)
-		if originalInfo == nil {
-			return fmt.Errorf("could not find %q", info.Name)
-		}
-
-		patch, patchType, err := createPatch(originalInfo.Object, currentObj, info)
-		if err != nil {
-			return err
-		}
-
-		helper.ServerDryRun = true
-		targetObj, err := helper.Patch(info.Namespace, info.Name, patchType, patch, nil)
-		if err != nil {
-			return fmt.Errorf("cannot patch %q with kind %s: %w", info.Name, kind, err)
-		}
-		out, _ = jsoniterator.ConfigCompatibleWithStandardLibrary.Marshal(targetObj)
-		pruneObj, err = deleteStatusAndTidyMetadata(out)
-		if err != nil {
-			return fmt.Errorf("prune current obj %q with kind %s: %w", info.Name, kind, err)
-		}
-		pruneOut, err = yaml.Marshal(pruneObj)
-		if err != nil {
-			return fmt.Errorf("prune current out %q with kind %s: %w", info.Name, kind, err)
-		}
-		installManifest = append(installManifest, yamlSeperator...)
-		installManifest = append(installManifest, pruneOut...)
-		return nil
-	})
-
-	return releaseManifest, installManifest, err
-}
-
-func createPatch(originalObj, currentObj runtime.Object, target *resource.Info) ([]byte, types.PatchType, error) {
-	oldData, err := json.Marshal(originalObj)
-	if err != nil {
-		return nil, types.StrategicMergePatchType, fmt.Errorf("serializing current configuration: %w", err)
-	}
-	newData, err := json.Marshal(target.Object)
-	if err != nil {
-		return nil, types.StrategicMergePatchType, fmt.Errorf("serializing target configuration: %w", err)
-	}
-
-	// Even if currentObj is nil (because it was not found), it will marshal just fine
-	currentData, err := json.Marshal(currentObj)
-	if err != nil {
-		return nil, types.StrategicMergePatchType, fmt.Errorf("serializing live configuration: %w", err)
-	}
-	// kind := target.Mapping.GroupVersionKind.Kind
-	// if kind == "Deployment" {
-	// 	curr, _ := yaml.Marshal(currentObj)
-	// 	fmt.Println(string(curr))
-	// }
-
-	// Get a versioned object
-	versionedObject := kube.AsVersioned(target)
-
-	// Unstructured objects, such as CRDs, may not have an not registered error
-	// returned from ConvertToVersion. Anything that's unstructured should
-	// use the jsonpatch.CreateMergePatch. Strategic Merge Patch is not supported
-	// on objects like CRDs.
-	_, isUnstructured := versionedObject.(runtime.Unstructured)
-
-	// On newer K8s versions, CRDs aren't unstructured but has this dedicated type
-	_, isCRD := versionedObject.(*apiextv1.CustomResourceDefinition)
-
-	if isUnstructured || isCRD {
-		// fall back to generic JSON merge patch
-		patch, err := jsonpatch.CreateMergePatch(oldData, newData)
-		return patch, types.MergePatchType, err
-	}
-
-	patchMeta, err := strategicpatch.NewPatchMetaFromStruct(versionedObject)
-	if err != nil {
-		return nil, types.StrategicMergePatchType, fmt.Errorf("unable to create patch metadata from object: %w", err)
-	}
-
-	patch, err := strategicpatch.CreateThreeWayMergePatch(oldData, newData, currentData, patchMeta, true)
-	return patch, types.StrategicMergePatchType, err
-}
-
-func objectKey(r *resource.Info) string {
-	gvk := r.Object.GetObjectKind().GroupVersionKind()
-	return fmt.Sprintf("%s/%s/%s/%s", gvk.GroupVersion().String(), gvk.Kind, r.Namespace, r.Name)
-}
-
-func existingResourceConflict(resources kube.ResourceList) (kube.ResourceList, error) {
-	var requireUpdate kube.ResourceList
-
-	err := resources.Visit(func(info *resource.Info, err error) error {
-		if err != nil {
-			return err
-		}
-
-		helper := resource.NewHelper(info.Client, info.Mapping)
-		_, err = helper.Get(info.Namespace, info.Name)
-		if err != nil {
-			if apierrors.IsNotFound(err) {
-				return nil
-			}
-			return fmt.Errorf("could not get information about the resource: %w", err)
-		}
-
-		requireUpdate.Append(info)
-		return nil
-	})
-
-	return requireUpdate, err
-}
-
-func deleteStatusAndTidyMetadata(obj []byte) (map[string]interface{}, error) {
-	var objectMap map[string]interface{}
-	err := jsoniterator.Unmarshal(obj, &objectMap)
-	if err != nil {
-		return nil, fmt.Errorf("could not unmarshal byte sequence: %w", err)
-	}
-
-	delete(objectMap, "status")
-
-	metadata := objectMap["metadata"].(map[string]interface{})
-
-	delete(metadata, "managedFields")
-	delete(metadata, "generation")
-
-	// See the below for the goal of this metadata tidy logic.
-	// https://github.com/databus23/helm-diff/issues/326#issuecomment-1008253274
-	if a := metadata["annotations"]; a != nil {
-		annotations := a.(map[string]interface{})
-		delete(annotations, "meta.helm.sh/release-name")
-		delete(annotations, "meta.helm.sh/release-namespace")
-		delete(annotations, "deployment.kubernetes.io/revision")
-
-		if len(annotations) == 0 {
-			delete(metadata, "annotations")
-		}
-	}
-
-	return objectMap, nil
-}