Isolated content of pkg/kustomize

pkg/app/application.go

@@ -0,0 +1,256 @@
+/*
+Copyright 2018 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 app
+
+import (
+	"bytes"
+	"encoding/json"
+
+	"github.com/ghodss/yaml"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	interror "k8s.io/kubectl/pkg/kustomize/internal/error"
+	"k8s.io/kubectl/pkg/kustomize/resource"
+	"k8s.io/kubectl/pkg/kustomize/transformers"
+	"k8s.io/kubectl/pkg/kustomize/types"
+	"k8s.io/kubectl/pkg/loader"
+)
+
+type Application interface {
+	// Resources computes and returns the resources for the app.
+	Resources() (resource.ResourceCollection, error)
+	// SemiResources computes and returns the resources without name hash and name reference for the app
+	SemiResources() (resource.ResourceCollection, error)
+	// RawResources computes and returns the raw resources from the kustomization file.
+	// It contains resources from
+	// 1) untransformed resources from current kustomization file
+	// 2) transformed resources from sub packages
+	RawResources() (resource.ResourceCollection, error)
+}
+
+var _ Application = &applicationImpl{}
+
+// Private implementation of the Application interface
+type applicationImpl struct {
+	kustomization *types.Kustomization
+	loader        loader.Loader
+}
+
+// NewApp parses the kustomization file at the path using the loader.
+func New(loader loader.Loader) (Application, error) {
+	content, err := loader.Load(constants.KustomizationFileName)
+	if err != nil {
+		return nil, err
+	}
+
+	var m types.Kustomization
+	err = unmarshal(content, &m)
+	if err != nil {
+		return nil, err
+	}
+	return &applicationImpl{kustomization: &m, loader: loader}, nil
+}
+
+// Resources computes and returns the resources from the kustomization file.
+// The namehashing for configmap/secrets and resolving name reference is only done
+// in the most top overlay once at the end of getting resources.
+func (a *applicationImpl) Resources() (resource.ResourceCollection, error) {
+	res, err := a.SemiResources()
+	if err != nil {
+		return nil, err
+	}
+	t, err := a.getHashAndReferenceTransformer()
+	if err != nil {
+		return nil, err
+	}
+	err = t.Transform(res)
+	if err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+// SemiResources computes and returns the resources without name hash and name reference for the app
+func (a *applicationImpl) SemiResources() (resource.ResourceCollection, error) {
+	errs := &interror.KustomizationErrors{}
+	raw, err := a.rawResources()
+	if err != nil {
+		errs.Append(err)
+	}
+
+	cms, err := resource.NewFromConfigMaps(a.loader, a.kustomization.ConfigMapGenerator)
+	if err != nil {
+		errs.Append(err)
+	}
+	secrets, err := resource.NewFromSecretGenerators(a.loader.Root(), a.kustomization.SecretGenerator)
+	if err != nil {
+		errs.Append(err)
+	}
+	res, err := resource.Merge(cms, secrets)
+	if err != nil {
+		return nil, err
+	}
+
+	allRes, err := resource.MergeWithOverride(raw, res)
+	if err != nil {
+		return nil, err
+	}
+
+	patches, err := resource.NewFromPatches(a.loader, a.kustomization.Patches)
+	if err != nil {
+		errs.Append(err)
+	}
+
+	if len(errs.Get()) > 0 {
+		return nil, errs
+	}
+
+	t, err := a.getTransformer(patches)
+	if err != nil {
+		return nil, err
+	}
+	err = t.Transform(allRes)
+	if err != nil {
+		return nil, err
+	}
+
+	return allRes, nil
+}
+
+// RawResources computes and returns the raw resources from the kustomization file.
+// The namehashing for configmap/secrets and resolving name reference is only done
+// in the most top overlay once at the end of getting resources.
+func (a *applicationImpl) RawResources() (resource.ResourceCollection, error) {
+	res, err := a.rawResources()
+	if err != nil {
+		return nil, err
+	}
+	t, err := a.getHashAndReferenceTransformer()
+	if err != nil {
+		return nil, err
+	}
+	err = t.Transform(res)
+	if err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (a *applicationImpl) rawResources() (resource.ResourceCollection, error) {
+	subAppResources, errs := a.subAppResources()
+	resources, err := resource.NewFromResources(a.loader, a.kustomization.Resources)
+	if err != nil {
+		errs.Append(err)
+	}
+
+	if len(errs.Get()) > 0 {
+		return nil, errs
+	}
+
+	return resource.Merge(resources, subAppResources)
+}
+
+func (a *applicationImpl) subAppResources() (resource.ResourceCollection, *interror.KustomizationErrors) {
+	sliceOfSubAppResources := []resource.ResourceCollection{}
+	errs := &interror.KustomizationErrors{}
+	for _, pkgPath := range a.kustomization.Bases {
+		subloader, err := a.loader.New(pkgPath)
+		if err != nil {
+			errs.Append(err)
+			continue
+		}
+		subapp, err := New(subloader)
+		if err != nil {
+			errs.Append(err)
+			continue
+		}
+		// Gather all transformed resources from subpackages.
+		subAppResources, err := subapp.SemiResources()
+		if err != nil {
+			errs.Append(err)
+			continue
+		}
+		sliceOfSubAppResources = append(sliceOfSubAppResources, subAppResources)
+	}
+	allResources, err := resource.Merge(sliceOfSubAppResources...)
+	if err != nil {
+		errs.Append(err)
+	}
+	return allResources, errs
+}
+
+// getTransformer generates the following transformers:
+// 1) apply overlay
+// 2) name prefix
+// 3) apply labels
+// 4) apply annotations
+func (a *applicationImpl) getTransformer(patches []*resource.Resource) (transformers.Transformer, error) {
+	ts := []transformers.Transformer{}
+
+	ot, err := transformers.NewOverlayTransformer(patches)
+	if err != nil {
+		return nil, err
+	}
+	ts = append(ts, ot)
+
+	npt, err := transformers.NewDefaultingNamePrefixTransformer(string(a.kustomization.NamePrefix))
+	if err != nil {
+		return nil, err
+	}
+	ts = append(ts, npt)
+
+	lt, err := transformers.NewDefaultingLabelsMapTransformer(a.kustomization.CommonLabels)
+	if err != nil {
+		return nil, err
+	}
+	ts = append(ts, lt)
+
+	at, err := transformers.NewDefaultingAnnotationsMapTransformer(a.kustomization.CommonAnnotations)
+	if err != nil {
+		return nil, err
+	}
+	ts = append(ts, at)
+
+	return transformers.NewMultiTransformer(ts), nil
+}
+
+// getHashAndReferenceTransformer generates the following transformers:
+// 1) name hash for configmap and secrests
+// 2) apply name reference
+func (a *applicationImpl) getHashAndReferenceTransformer() (transformers.Transformer, error) {
+	ts := []transformers.Transformer{}
+	nht := transformers.NewNameHashTransformer()
+	ts = append(ts, nht)
+
+	nrt, err := transformers.NewDefaultingNameReferenceTransformer()
+	if err != nil {
+		return nil, err
+	}
+	ts = append(ts, nrt)
+	return transformers.NewMultiTransformer(ts), nil
+}
+
+func unmarshal(y []byte, o interface{}) error {
+	j, err := yaml.YAMLToJSON(y)
+	if err != nil {
+		return err
+	}
+
+	dec := json.NewDecoder(bytes.NewReader(j))
+	dec.DisallowUnknownFields()
+	return dec.Decode(o)
+}