Rewrite the renderResources function to make it usable

Signed-off-by: Matt Butcher <matt.butcher@microsoft.com>

cmd/helm/testdata/helmhome/helm/repository/test-name-index.yaml

@@ -1,3 +1,3 @@
 apiVersion: v1
 entries: {}
-generated: "2020-06-23T10:01:59.2530763-07:00"
+generated: "2020-09-01T10:53:17.923514-06:00"

internal/fileutil/fileutil.go

@@ -22,15 +22,18 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/pkg/errors"
+
 	"helm.sh/helm/v3/internal/third_party/dep/fs"
 )
 
 // AtomicWriteFile atomically (as atomic as os.Rename allows) writes a file to a
 // disk.
 func AtomicWriteFile(filename string, reader io.Reader, mode os.FileMode) error {
-	tempFile, err := ioutil.TempFile(filepath.Split(filename))
+	tdir, tname := filepath.Split(filename)
+	tempFile, err := ioutil.TempFile(tdir, tname)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, "failed to create %s in dir %s", tname, tdir)
 	}
 	tempName := tempFile.Name()
 

pkg/action/action.go

@@ -96,9 +96,302 @@ type Configuration struct {
 	Log func(string, ...interface{})
 }
 
+// renderedResources is an internal representation of a rendered set of resources
+type renderedResources struct {
+	hooks     []*renderedDocument
+	resources []*renderedDocument
+	notes     string
+	crds      []*renderedDocument
+}
+
+// writeDirectory creates a directory and writes the rendered resources to that directory
+//
+// This will return an error if the directory already exists, if it can't be created, or
+// if any file fails to write.
+func (r *renderedResources) writeDirectory(outdir string, flags renderFlags) error {
+	mode := os.FileMode(0755)
+	if _, err := os.Stat(outdir); err != nil && !os.IsNotExist(err) {
+		return fmt.Errorf("unexpected error with directory %q: %s", outdir, err)
+	}
+
+	if err := os.MkdirAll(outdir, mode); err != nil {
+		return err
+	}
+
+	all := []*renderedDocument{}
+
+	if flags.includeCrds {
+		all = append(all, r.crds...)
+	}
+
+	if flags.includeHooks {
+		all = append(all, r.hooks...)
+	}
+
+	all = append(all, r.resources...)
+
+	// Write each file
+	for _, doc := range all {
+		// Write to disk
+		filename := filepath.Join(outdir, doc.name)
+		// Because doc.name pay have path components, we need to make sure all of the
+		// directories are created before we attempt to write a file.
+		destdir := filepath.Dir(filename)
+		if err := os.MkdirAll(destdir, 0755); err != nil {
+			errors.Wrapf(err, "could not create dir %s", destdir)
+		}
+
+		fh, err := os.OpenFile(filename, os.O_APPEND|os.O_RDWR|os.O_CREATE, mode)
+		if err != nil {
+			return errors.Wrapf(err, "could not create/append to file %s", filename)
+		}
+		_, err = fh.Write(doc.asBuffer().Bytes())
+		fh.Close()
+		if err != nil {
+			return errors.Wrapf(err, "could not write to file %s", filename)
+		}
+	}
+	return nil
+}
+
+// Get the resources as a single manifest
+func (r *renderedResources) manifest() string {
+	b := bytes.Buffer{}
+	for _, item := range r.resources {
+		//b.WriteString("\n---\n# Source: ")
+		//b.WriteString(item.name)
+		//b.WriteRune('\n')
+		b.WriteString("---\n")
+		b.WriteString(item.content)
+	}
+	return b.String()
+}
+
+// toBuffer gets the resources as a bytes.Buffer
+//
+// Depending on flags, this may return hooks and CRDs
+func (r *renderedResources) toBuffer(flags renderFlags) *bytes.Buffer {
+	b := bytes.Buffer{}
+	writeItem := func(item *renderedDocument) {
+		//b.WriteString("---\n# Source: ")
+		//b.WriteString(item.name)
+		//b.WriteRune('\n')
+		b.WriteString("---\n")
+		b.WriteString(item.content)
+	}
+
+	// CRDs are always first
+	if flags.includeCrds {
+		for _, item := range r.crds {
+			writeItem(item)
+		}
+	}
+
+	// Regular files
+	for _, item := range r.resources {
+		writeItem(item)
+	}
+
+	// Hooks are last
+	if flags.includeHooks {
+		for _, item := range r.hooks {
+			writeItem(item)
+		}
+	}
+	return &b
+}
+
+// releaseHooks returns the hooks formatted as release.Hook objects
+// This might be unnecessary if postRender is done well
+func (r *renderedResources) releaseHooks(c *Configuration) ([]*release.Hook, error) {
+	files := map[string]string{}
+	for _, h := range r.hooks {
+		files[h.name] = h.content
+	}
+	caps, err := c.getCapabilities()
+	if err != nil {
+		return nil, err
+	}
+	hooks, _, err := releaseutil.SortManifests(files, caps.APIVersions, releaseutil.InstallOrder)
+	return hooks, err
+}
+
+// postRender calls the post-renderer on resources, then tries to reset the object
+//
+// post-render collapses all of the resources into one long byte array. This is a problem
+// because the file objects are lost, and there is no way to pick out the resulting
+// resources and re-assign them to file names.
+func (r *renderedResources) postRender(pr postrender.PostRenderer, flags renderFlags) (*bytes.Buffer, error) {
+	b := r.toBuffer(flags)
+	var err error
+	b, err = pr.Run(b)
+	if err != nil {
+		return b, errors.Wrap(err, "error while running post render on files")
+	}
+
+	// We need to get hooks back out of this, which is an epic hack because they
+	// were all just shoved into the same I/O cycle with the rest of the manifests.
+	// The SortManifests function is our best tool for finding hooks, so we can use that.
+	// But first we have to split all of the manifests again and give them fake
+	// filenames because the filenames were lost. Or maybe we can just parse the manifests
+	// and look at the labels. Not sure we need filenames.
+
+	// Note that you SHOULD NOT try to add special CRD handling here. Any CRD that is
+	// in the `crds/` directory SHOULD NOT be sent to the post-rendered. Once it is sent
+	// to post-render, it is indistinguishable from templated files (including CRDs that
+	// were declared that way). So if someone wants to add CRD support to postRender, those
+	// CRDs must be put through the renderer as a _separate operation_, not as part of
+	// the main post-render. Please do not try clever hacks around this system, because
+	// we will not trust the post-renderer to correctly distinguish between CRDs that
+	// should be pre-loaded and those that should be loaded with the rest of the chart.
+	// In other words, attempting to use labels or annotations to distinguish CRDs is not
+	// a good idea, because the post-renderer could delete or manipulate those, which can
+	// have long-term implications for managing the installation.
+
+	return b, nil
+}
+
+// renderedDocument represents a rendered piece of generic YAML content
+type renderedDocument struct {
+	name    string
+	content string
+}
+
+// asBuffer converts the document to a Buffer containing the serialized document contents.
+//
+// This prepends the stream separator (---) to the buffer.
+func (r *renderedDocument) asBuffer() *bytes.Buffer {
+	buf := bytes.NewBufferString("---\n")
+	buf.WriteString(r.content)
+	return buf
+}
+
+// renderFlags is the flag set for rendering content
+type renderFlags struct {
+	dryRun       bool
+	subNotes     bool
+	includeCrds  bool
+	includeHooks bool
+}
+
+const sourceComment = "# Source: %s\n%s\n"
+
+func (c *Configuration) renderResources2(ch *chart.Chart, values chartutil.Values, flags renderFlags) (*renderedResources, error) {
+	res := &renderedResources{}
+
+	// Get the capabilities from k8s
+	// TODO: If `helm template` is called, do we skip this?
+	caps, err := c.getCapabilities()
+	if err != nil {
+		return res, err
+	}
+
+	// If chart is restricted to particular k8s version, verify a supported version
+	if ch.Metadata.KubeVersion != "" {
+		if !chartutil.IsCompatibleRange(ch.Metadata.KubeVersion, caps.KubeVersion.String()) {
+			return res, errors.Errorf("chart requires kubeVersion: %s which is incompatible with Kubernetes %s", ch.Metadata.KubeVersion, caps.KubeVersion.String())
+		}
+	}
+
+	var files map[string]string
+	var err2 error
+
+	// A `helm template` or `helm install --dry-run` should not talk to the remote cluster.
+	// It will break in interesting and exotic ways because other data (e.g. discovery)
+	// is mocked. It is not up to the template author to decide when the user wants to
+	// connect to the cluster. So when the user says to dry run, respect the user's
+	// wishes and do not connect to the cluster.
+	if !flags.dryRun && c.RESTClientGetter != nil {
+		rest, err := c.RESTClientGetter.ToRESTConfig()
+		if err != nil {
+			return res, err
+		}
+		files, err2 = engine.RenderWithClient(ch, values, rest)
+	} else {
+		files, err2 = engine.Render(ch, values)
+	}
+
+	if err2 != nil {
+		return res, err2
+	}
+
+	// Copy the CRDs into the results
+	for _, c := range ch.CRDObjects() {
+		res.crds = append(res.crds, &renderedDocument{
+			name:    c.Name, // Is this a bug? Shouldn't it be c.Filename?
+			content: fmt.Sprintf(sourceComment, c.Name, c.File.Data[:]),
+		})
+	}
+
+	// NOTES.txt gets rendered like all the other files, but because it's not a hook nor a resource,
+	// pull it out of here into a separate file so that we can actually use the output of the rendered
+	// text file. We have to spin through this map because the file contains path information, so we
+	// look for terminating NOTES.txt. We also remove it from the files so that we don't have to skip
+	// it in the sortHooks.
+	var notesBuffer bytes.Buffer
+	for k, v := range files {
+		if strings.HasSuffix(k, notesFileSuffix) {
+			if flags.subNotes || (k == path.Join(ch.Name(), "templates", notesFileSuffix)) {
+				// If buffer contains data, add newline before adding more
+				if notesBuffer.Len() > 0 {
+					notesBuffer.WriteString("\n")
+				}
+				notesBuffer.WriteString(v)
+			}
+			delete(files, k)
+		}
+	}
+	res.notes = notesBuffer.String()
+
+	// Sort hooks, manifests, and partials. Only hooks and manifests are returned,
+	// as partials are not used after renderer.Render. Empty manifests are also
+	// removed here.
+	hs, manifests, err := releaseutil.SortManifests(files, caps.APIVersions, releaseutil.InstallOrder)
+	if err != nil {
+		// By catching parse errors here, we can prevent bogus releases from going
+		// to Kubernetes.
+		//
+		// We return the files to help the user debug parser errors.
+		//
+		// TODO: Why not use a custom error type to do this?
+		for name, content := range files {
+			if strings.TrimSpace(content) == "" {
+				continue
+			}
+			// Otherwise, insert this into the results
+			doc := renderedDocument{
+				name:    name,
+				content: fmt.Sprintf(sourceComment, name, content),
+			}
+			res.resources = append(res.resources, &doc)
+		}
+		return res, err
+	}
+
+	// Copy the hooks into the result
+	//res.hooks = hs
+	for _, h := range hs {
+		res.hooks = append(res.hooks, &renderedDocument{
+			name:    h.Path,
+			content: fmt.Sprintf(sourceComment, h.Path, h.Manifest),
+		})
+	}
+
+	// Copy the manifests
+	for _, m := range manifests {
+		res.resources = append(res.resources, &renderedDocument{
+			name:    m.Name,
+			content: fmt.Sprintf(sourceComment, m.Name, m.Content),
+		})
+	}
+
+	return res, nil
+}
+
 // renderResources renders the templates in a chart
 //
 // TODO: This function is badly in need of a refactor.
+/*
 func (c *Configuration) renderResources(ch *chart.Chart, values chartutil.Values, releaseName, outputDir string, subNotes, useReleaseName, includeCrds bool, disableHooks bool, pr postrender.PostRenderer, dryRun bool) ([]*release.Hook, *bytes.Buffer, string, error) {
 	hs := []*release.Hook{}
 	b := bytes.NewBuffer(nil)
@@ -239,6 +532,7 @@ func (c *Configuration) renderResources(ch *chart.Chart, values chartutil.Values
 
 	return hs, b, notes, nil
 }
+*/
 
 // RESTClientGetter gets the rest client
 type RESTClientGetter interface {

pkg/action/action_test.go

@@ -353,3 +353,52 @@ func TestValidName(t *testing.T) {
 		}
 	}
 }
+
+func TestRenderedResources(t *testing.T) {
+	hook := `apiVersion: v1
+kind: Secret
+metadata:
+  name: hook
+  annotations:
+    "helm.sh/hook": pre-install
+    "helm.sh/hook-weight": 999
+stringData:
+  hello: world`
+
+	r := renderedResources{
+		hooks: []*renderedDocument{
+			{name: "hook", content: hook},
+		},
+		resources: []*renderedDocument{
+			{name: "manifest1", content: "manifest 1\n"},
+			{name: "manifest2", content: "manifest 2"},
+		},
+		notes: "NOTES",
+		crds: []*renderedDocument{
+			{name: "crd", content: "crd"},
+		},
+	}
+
+	expect := `---
+manifest 1
+---
+manifest 2`
+
+	if r.manifest() != expect {
+		t.Errorf("Expected two manifests. Expected: %q\nGot %q", expect, r.manifest())
+	}
+
+	hooks, err := r.releaseHooks(actionConfigFixture(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hooks) != 1 {
+		t.Fatalf("Expected 1 hook, got %d", len(hooks))
+	}
+	if hooks[0].Name != "hook" {
+		t.Errorf("Expected name 'hook', got %q", hooks[0].Name)
+	}
+	if hooks[0].Manifest != hook {
+		t.Errorf("Expected manifest\n%q, got\n%q", hook, hooks[0].Manifest)
+	}
+}

pkg/action/install.go

@@ -235,12 +235,25 @@ func (i *Install) Run(chrt *chart.Chart, vals map[string]interface{}) (*release.
 
 	rel := i.createRelease(chrt, vals)
 
-	var manifestDoc *bytes.Buffer
-	rel.Hooks, manifestDoc, rel.Info.Notes, err = i.cfg.renderResources(chrt, valuesToRender, i.ReleaseName, i.OutputDir, i.SubNotes, i.UseReleaseName, i.IncludeCRDs, i.DisableHooks, i.PostRenderer, i.DryRun)
-	// Even for errors, attach this if available
-	if manifestDoc != nil {
-		rel.Manifest = manifestDoc.String()
+	rflags := renderFlags{
+		includeCrds:  i.IncludeCRDs,
+		includeHooks: !i.DisableHooks,
+		dryRun:       i.DryRun,
+		subNotes:     i.SubNotes,
 	}
+	rendered, err := i.cfg.renderResources2(chrt, valuesToRender, rflags)
+	var err2 error
+	// Do our best to attach content. Even if there is an error, this may be informative
+	rel.Manifest = rendered.toBuffer(rflags).String()
+	rel.Hooks, err2 = rendered.releaseHooks(i.cfg)
+	if err2 != nil {
+		return rel, err2
+	}
+	rel.Info.Notes = rendered.notes
+
+	//var manifestDoc *bytes.Buffer
+	//rel.Hooks, manifestDoc, rel.Info.Notes, err = i.cfg.renderResources(chrt, valuesToRender, i.ReleaseName, i.OutputDir, i.SubNotes, i.UseReleaseName, i.IncludeCRDs, i.DisableHooks, i.PostRenderer, i.DryRun)
+
 	// Check error from render
 	if err != nil {
 		rel.SetStatus(release.StatusFailed, fmt.Sprintf("failed to render resource: %s", err.Error()))
@@ -248,6 +261,29 @@ func (i *Install) Run(chrt *chart.Chart, vals map[string]interface{}) (*release.
 		return rel, err
 	}
 
+	// Run the post-render.
+	// Note that this was moved before the i.OutputDir check so that post-render support
+	// can be added to 'helm template'
+	if i.PostRenderer != nil {
+		if err := doPostRender(i.PostRenderer, rendered.toBuffer(rflags), rel, caps); err != nil {
+			return rel, err
+		}
+	}
+
+	// Write to an output directory if necessary.
+	if i.OutputDir != "" {
+		dest := i.OutputDir
+		if i.UseReleaseName {
+			dest = filepath.Join(i.OutputDir, i.ReleaseName)
+		}
+		// TODO: Is there any condition under which we want to change the includeHooks or
+		// includeCrds flag?
+		if err := rendered.writeDirectory(dest, rflags); err != nil {
+			i.cfg.Log("Could not write files to %s: %s", dest, err)
+			return rel, err
+		}
+	}
+
 	// Mark this release as in-progress
 	rel.SetStatus(release.StatusPendingInstall, "Initial install underway")
 
@@ -377,6 +413,56 @@ func (i *Install) Run(chrt *chart.Chart, vals map[string]interface{}) (*release.
 	return rel, nil
 }
 
+// doPostRender performs a PostRender run and modifies the release appropriately.
+//
+// A post-render takes the rendered result of templates, pipes it out to the external
+// processor, and then receives the results. There is no assurance that the incoming
+// data bears any resemblance to the rendered templates. Therefore, we have to go through
+// some extra steps to re-process that data, shaping it back into the form that Helm
+// expects. This can be a "lossy" process, in the sense that we lose a strong correlation
+// between how the input (the Helm chart) correlates to specific outputs (Kubernetes
+// objects).
+func doPostRender(pr postrender.PostRenderer, manifest *bytes.Buffer, rel *release.Release, caps *chartutil.Capabilities) error {
+	// Execute the renderer, and with the result it gives us back.
+	manifest, err := pr.Run(manifest)
+	if err != nil {
+		return errors.Wrap(err, "error while running post render on files")
+	}
+
+	// Attempt to re-parse the objects into Helm internal representations (namely file->data).
+	// This performs some validation on the YAML, but is not exhaustive.
+	files, err := postrender.Reparse(manifest.Bytes())
+	if err != nil {
+		return errors.Wrap(err, "YAML returned from post-render cannot be parsed")
+	}
+
+	// Now we re-sort the manifests. We do this because a post-render can modify things
+	// in an unpredictable way. For example, it may rewrite hooks to not be hooks.
+	var resources []releaseutil.Manifest
+	rel.Hooks, resources, err = releaseutil.SortManifests(files, caps.APIVersions, releaseutil.InstallOrder)
+	if err != nil {
+		var b bytes.Buffer
+		// If an error occurse, we try to put together a decent piece of debuggable data,
+		// since this data is the output of an external process.
+		for name, content := range files {
+			if strings.TrimSpace(content) == "" {
+				continue
+			}
+			fmt.Fprintf(&b, "---\n# Source: %s\n%s\n", name, content)
+		}
+		rel.Manifest = b.String()
+		return err
+	}
+
+	// Now we just need to re-attach the resources to the release.
+	var buf bytes.Buffer
+	for _, m := range resources {
+		fmt.Fprintf(&buf, "---\n# Source: %s\n%s\n", m.Name, m.Content)
+	}
+	rel.Manifest = buf.String()
+	return nil
+}
+
 func (i *Install) failRelease(rel *release.Release, err error) (*release.Release, error) {
 	rel.SetStatus(release.StatusFailed, fmt.Sprintf("Release %q failed: %s", i.ReleaseName, err.Error()))
 	if i.Atomic {

pkg/action/install_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package action
 
 import (
+	"bytes"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -67,7 +68,8 @@ func TestInstallRelease(t *testing.T) {
 	is.NoError(err)
 
 	is.Len(rel.Hooks, 1)
-	is.Equal(rel.Hooks[0].Manifest, manifestWithHook)
+	hookWithComment := "# Source: hello/templates/hooks\n" + manifestWithHook
+	is.Equal(rel.Hooks[0].Manifest, hookWithComment)
 	is.Equal(rel.Hooks[0].Events[0], release.HookPostInstall)
 	is.Equal(rel.Hooks[0].Events[1], release.HookPreDelete, "Expected event 0 is pre-delete")
 
@@ -100,8 +102,9 @@ func TestInstallReleaseWithValues(t *testing.T) {
 	rel, err := instAction.cfg.Releases.Get(res.Name, res.Version)
 	is.NoError(err)
 
+	hookWithComment := "# Source: hello/templates/hooks\n" + manifestWithHook
 	is.Len(rel.Hooks, 1)
-	is.Equal(rel.Hooks[0].Manifest, manifestWithHook)
+	is.Equal(rel.Hooks[0].Manifest, hookWithComment)
 	is.Equal(rel.Hooks[0].Events[0], release.HookPostInstall)
 	is.Equal(rel.Hooks[0].Events[1], release.HookPreDelete, "Expected event 0 is pre-delete")
 
@@ -149,7 +152,8 @@ func TestInstallRelease_WithNotes(t *testing.T) {
 	rel, err := instAction.cfg.Releases.Get(res.Name, res.Version)
 	is.NoError(err)
 	is.Len(rel.Hooks, 1)
-	is.Equal(rel.Hooks[0].Manifest, manifestWithHook)
+	hookWithComment := "# Source: hello/templates/hooks\n" + manifestWithHook
+	is.Equal(rel.Hooks[0].Manifest, hookWithComment)
 	is.Equal(rel.Hooks[0].Events[0], release.HookPostInstall)
 	is.Equal(rel.Hooks[0].Events[1], release.HookPreDelete, "Expected event 0 is pre-delete")
 	is.NotEqual(len(res.Manifest), 0)
@@ -657,3 +661,31 @@ func TestNameAndChartGenerateName(t *testing.T) {
 		})
 	}
 }
+
+type PostRenderFixture struct {
+	output string
+}
+
+func (p *PostRenderFixture) Run(input *bytes.Buffer) (*bytes.Buffer, error) {
+	return bytes.NewBufferString(p.output), nil
+}
+
+func TestDoPostRender(t *testing.T) {
+	postRenderIn := "input"
+	postRenderOut := `
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: post-render-out
+`
+	caps := chartutil.DefaultCapabilities
+	pfx := &PostRenderFixture{postRenderOut}
+	rel := &release.Release{}
+
+	if err := doPostRender(pfx, bytes.NewBufferString(postRenderIn), rel, caps); err != nil {
+		t.Fatal(err)
+	}
+
+	expect := fmt.Sprintf("---\n# Source: v1.ConfigMap.post-render-out.yaml%s", postRenderOut)
+	assert.Equal(t, rel.Manifest, expect)
+}

pkg/action/upgrade.go

@@ -222,12 +222,22 @@ func (u *Upgrade) prepareUpgrade(name string, chart *chart.Chart, vals map[strin
 		return nil, nil, err
 	}
 
-	hooks, manifestDoc, notesTxt, err := u.cfg.renderResources(chart, valuesToRender, "", "", u.SubNotes, false, false, false, u.PostRenderer, u.DryRun)
+	/*
+		hooks, manifestDoc, notesTxt, err := u.cfg.renderResources(chart, valuesToRender, "", "", u.SubNotes, false, false, false, u.PostRenderer, u.DryRun)
+
+	*/
+	rflags := renderFlags{dryRun: u.DryRun, includeHooks: true, subNotes: u.SubNotes}
+	rendered, err := u.cfg.renderResources2(chart, valuesToRender, rflags)
 	if err != nil {
 		return nil, nil, err
 	}
 
 	// Store an upgraded release.
+	manifest := rendered.manifest()
+	hooks, err := rendered.releaseHooks(u.cfg)
+	if err != nil {
+		return nil, nil, err
+	}
 	upgradedRelease := &release.Release{
 		Name:      name,
 		Namespace: currentRelease.Namespace,
@@ -238,16 +248,21 @@ func (u *Upgrade) prepareUpgrade(name string, chart *chart.Chart, vals map[strin
 			LastDeployed:  Timestamper(),
 			Status:        release.StatusPendingUpgrade,
 			Description:   "Preparing upgrade", // This should be overwritten later.
+			Notes:         rendered.notes,
 		},
 		Version:  revision,
-		Manifest: manifestDoc.String(),
+		Manifest: manifest,
 		Hooks:    hooks,
 	}
 
-	if len(notesTxt) > 0 {
-		upgradedRelease.Info.Notes = notesTxt
+	// Run the post-render.
+	if u.PostRenderer != nil {
+		if err := doPostRender(u.PostRenderer, rendered.toBuffer(rflags), upgradedRelease, caps); err != nil {
+			return currentRelease, upgradedRelease, err
+		}
 	}
-	err = validateManifest(u.cfg.KubeClient, manifestDoc.Bytes(), !u.DisableOpenAPIValidation)
+
+	err = validateManifest(u.cfg.KubeClient, []byte(upgradedRelease.Manifest), !u.DisableOpenAPIValidation)
 	return currentRelease, upgradedRelease, err
 }
 

pkg/postrender/reparse.go

@@ -0,0 +1,84 @@
+/*
+Copyright The Helm 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 postrender
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+
+	"github.com/pkg/errors"
+	"sigs.k8s.io/yaml"
+)
+
+// Reparse attempts to split a YAML stream as returned by a post-rendered back into a map of files
+//
+// Elsewhere in Helm, it treats individual YAMLs as filename/content pairs. The post-render
+// is inserted into the middle of that context. Thus, when a post-render returns, we need
+// a way to convert it back into a map[string]string. There are no assumptions about
+// what the filename looks like when it comes back from the postrenderer, so we can take
+// some liberties with naming here that we cannot take in other contexts.
+//
+// Note that the YAML specification is very clear that the string '\n---\n' is a document
+// split sequence. So we can cheaply process using that method. Also we rely on the
+// Kubernetes requirement that metadata.name is a required field for all valid Kubernetes
+// resource instances, as are apiVersion and kind.
+func Reparse(manifest []byte) (map[string]string, error) {
+	sep := []byte("\n---\n")
+	manifests := bytes.Split(manifest, sep)
+	files := map[string]string{}
+
+	for _, resource := range manifests {
+		if s := strings.TrimSpace(string(resource)); s == "" {
+			continue
+		}
+		h := &header{}
+		if err := yaml.Unmarshal(resource, h); err != nil {
+			return files, errors.Wrap(err, "manifest returned from post render is not well-formed")
+		}
+
+		// Name and Kind are required on every manifest
+		if h.Kind == "" {
+			return files, fmt.Errorf("manifest returned by post-render has no kind:\n%s", resource)
+		}
+		if h.Metadata.Name == "" {
+			return files, fmt.Errorf("manifest returned by post-render has no name:\n%s", resource)
+		}
+		name := h.filename()
+		if _, ok := files[name]; ok {
+			return files, fmt.Errorf("two or more post-rendered objects have the name %q", name)
+		}
+		files[name] = string(resource)
+	}
+	return files, nil
+}
+
+type header struct {
+	APIVersion string `json:"apiVersion"`
+	Kind       string
+	Metadata   struct {
+		Name string
+	}
+}
+
+func (h *header) filename() string {
+	name := ""
+	if h.APIVersion != "" {
+		name = h.APIVersion + "."
+	}
+	return fmt.Sprintf("%s%s.%s.yaml", name, h.Kind, h.Metadata.Name)
+}

pkg/postrender/reparse_test.go

@@ -0,0 +1,127 @@
+/*
+Copyright The Helm 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 postrender
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var goodYaml = `
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: hollow-men
+data: |-
+  This is the way the world ends
+  This is the way the world ends
+  This is the way the world ends
+  Not with a bang but a whimper.
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: waste-land
+data: |-
+  To Carthage then I came	
+  Burning burning burning burning
+`
+
+var duplicateYaml = `
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: hollow-men
+data: |-
+  This is the way the world ends
+  This is the way the world ends
+  This is the way the world ends
+  Not with a bang but a whimper.
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: hollow-men
+data: |-
+  This is the way the world ends
+  This is the way the world ends
+  This is the way the world ends
+  Not with a bang but a whimper.
+`
+
+var nonameYaml = `
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+data: |-
+  This is the way the world ends
+  This is the way the world ends
+  This is the way the world ends
+  Not with a bang but a whimper.
+`
+var unkindYaml = `
+---
+apiVersion: v1
+metadata:
+  name: hollow-men
+data: |-
+  This is the way the world ends
+  This is the way the world ends
+  This is the way the world ends
+  Not with a bang but a whimper.
+`
+
+var hollowMen = `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: hollow-men
+data: |-
+  This is the way the world ends
+  This is the way the world ends
+  This is the way the world ends
+  Not with a bang but a whimper.`
+
+func TestReparse(t *testing.T) {
+	is := assert.New(t)
+	res, err := Reparse([]byte(goodYaml))
+	is.NoError(err, goodYaml)
+
+	is.Len(res, 2, "two map entries")
+	names := []string{"v1.ConfigMap.hollow-men.yaml", "v1.ConfigMap.waste-land.yaml"}
+	for _, name := range names {
+		content, ok := res[name]
+		is.True(ok, "entry for %s exists", name)
+		is.NotEmpty(content)
+	}
+	is.Equal(hollowMen, res[names[0]], "content matches")
+
+	// duplicate failure
+	_, err = Reparse([]byte(duplicateYaml))
+	is.Error(err, "duplicate YAML fails to parse")
+
+	// name is missing
+	_, err = Reparse([]byte(nonameYaml))
+	is.Error(err, "unnamed object fails to parse")
+
+	// kind is missing
+	_, err = Reparse([]byte(unkindYaml))
+	is.Error(err, "kindless object fails to parse")
+}