feat: Experimental support for Helm 3.0.0-beta.3

Tested with `helm diff upgrade` only. Changes for other helm-diff sub-commands will be made in coming weeks.

Changes:

- Migrated from Glide to Go modules as helm-diff was unable to build with Glide due to bunch of missing transitive dependencies probably due to that some projects are not managed by Glide
- Auto-detection of the plugin context(helm 2 or 3)
- `helm diff upgrade` has been enhanced so that it turns into Helm 3 mode

Pre-requisites:

- You need to `helm plugin install` with `helm` of 3.0.0-x as the plugin installation directory has been changed from that of helm 2.x.

Ref #147

Author: mumoshu

cmd/helm.go

@@ -79,7 +79,13 @@ func locateChartPath(name, version string, verify bool, keyring string) (string,
 		return name, fmt.Errorf("path %q not found", name)
 	}
 
-	crepo := filepath.Join(helmpath.Home(homePath()).Repository(), name)
+	var crepo string
+	if os.Getenv("HELM_REPOSITORY_CONFIG") != "" {
+		crepo = os.Getenv("HELM_REPOSITORY_CONFIG")
+	} else {
+		crepo = filepath.Join(helmpath.Home(homePath()).Repository(), name)
+	}
+
 	if _, err := os.Stat(crepo); err == nil {
 		return filepath.Abs(crepo)
 	}

cmd/helm3.go

@@ -0,0 +1,323 @@
+package cmd
+
+import (
+	"fmt"
+	"github.com/databus23/helm-diff/diff"
+	"github.com/databus23/helm-diff/manifest"
+	"github.com/pkg/errors"
+	"helm.sh/helm/pkg/kube"
+	"log"
+	"os"
+	"strings"
+	"sync"
+
+	"helm.sh/helm/pkg/action"
+	"helm.sh/helm/pkg/chart"
+	"helm.sh/helm/pkg/chart/loader"
+	"helm.sh/helm/pkg/cli"
+	"helm.sh/helm/pkg/cli/values"
+	"helm.sh/helm/pkg/getter"
+	helm3release "helm.sh/helm/pkg/release"
+	"helm.sh/helm/pkg/storage"
+	"helm.sh/helm/pkg/storage/driver"
+
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+
+	// Import to initialize client auth plugins.
+	_ "k8s.io/client-go/plugin/pkg/client/auth"
+)
+
+var (
+	config      genericclioptions.RESTClientGetter
+	configOnce  sync.Once
+	envSettings *cli.EnvSettings
+)
+
+func init() {
+	envSettings = cli.New()
+}
+
+// Helm3Client is the client for interacting with Helm3 releases
+type Helm3Client struct {
+	conf     *action.Configuration
+	settings *cli.EnvSettings
+}
+
+func helm3Run(d *diffCmd, chartPath string) error {
+	name := d.release
+	chart := d.chart
+
+	helm3 := NewHelm3()
+
+	releaseResponse, err := helm3.Get(name, 0)
+
+	var newInstall bool
+	if err != nil && strings.Contains(err.Error(), fmt.Sprintf("release: %q not found", d.release)) {
+		if d.allowUnreleased {
+			fmt.Printf("********************\n\n\tRelease was not present in Helm.  Diff will show entire contents as new.\n\n********************\n")
+			newInstall = true
+			err = nil
+		} else {
+			fmt.Printf("********************\n\n\tRelease was not present in Helm.  Include the `--allow-unreleased` to perform diff without exiting in error.\n\n********************\n")
+		}
+	}
+
+	if err != nil {
+		return prettyError(fmt.Errorf("get: %v", err))
+	}
+
+	var currentSpecs, newSpecs map[string]*manifest.MappingResult
+	valOpts := &values.Options{
+		ValueFiles:   d.valueFiles,
+		Values:       d.values,
+		StringValues: d.stringValues,
+	}
+	if newInstall {
+		installResponse, err := helm3.Install(d.release, chart, valOpts)
+		if err != nil {
+			return prettyError(fmt.Errorf("install: %v", err))
+		}
+
+		currentSpecs = make(map[string]*manifest.MappingResult)
+		newSpecs = manifest.Parse(installResponse.Manifest, installResponse.Namespace)
+	} else {
+		upgradeResponse, err := helm3.Upgrade(d.release, chart, valOpts)
+		if err != nil {
+			return prettyError(fmt.Errorf("upgrade: %v", err))
+		}
+
+		if d.noHooks {
+			currentSpecs = manifest.Parse(releaseResponse.Manifest, releaseResponse.Namespace)
+			newSpecs = manifest.Parse(upgradeResponse.Manifest, upgradeResponse.Namespace)
+		} else {
+			currentSpecs = ParseRelease(releaseResponse, d.includeTests)
+			newSpecs = ParseRelease(upgradeResponse, d.includeTests)
+		}
+	}
+
+	seenAnyChanges := diff.Manifests(currentSpecs, newSpecs, d.suppressedKinds, d.outputContext, os.Stdout)
+
+	if d.detailedExitCode && seenAnyChanges {
+		return Error{
+			error: errors.New("identified at least one change, exiting with non-zero exit code (detailed-exitcode parameter enabled)"),
+			Code:  2,
+		}
+	}
+
+	return nil
+}
+
+// ParseRelease parses Helm v3 release to obtain MappingResults
+func ParseRelease(release *helm3release.Release, includeTests bool) map[string]*manifest.MappingResult {
+	man := release.Manifest
+	for _, hook := range release.Hooks {
+		if !includeTests && isTestHook(hook.Events) {
+			continue
+		}
+
+		man += "\n---\n"
+		man += fmt.Sprintf("# Source: %s\n", hook.Path)
+		man += hook.Manifest
+	}
+	return manifest.Parse(man, release.Namespace)
+}
+
+func isTestHook(hookEvents []helm3release.HookEvent) bool {
+	for _, event := range hookEvents {
+		if event == helm3release.HookTest {
+			return true
+		}
+	}
+
+	return false
+}
+
+// NewHelm3 returns Helm3 client for use within helm-diff
+func NewHelm3() *Helm3Client {
+	conf := &action.Configuration{}
+	initActionConfig(conf, false)
+	return &Helm3Client{
+		conf:     conf,
+		settings: envSettings,
+	}
+}
+
+// Get returns the named release
+func (helm3 *Helm3Client) Get(name string, version int) (*helm3release.Release, error) {
+	if version <= 0 {
+		return helm3.conf.Releases.Last(name)
+	}
+
+	return helm3.conf.Releases.Get(name, version)
+}
+
+// Upgrade returns the named release after an upgrade
+func (helm3 *Helm3Client) Upgrade(name, chart string, valueOpts *values.Options) (*helm3release.Release, error) {
+	conf := helm3.conf
+
+	settings := helm3.settings
+
+	client := action.NewUpgrade(conf)
+	client.DryRun = true
+
+	getters := getter.All(settings)
+	vals, err := valueOpts.MergeValues(getters)
+	if err != nil {
+		return nil, fmt.Errorf("merge values: %v", err)
+	}
+
+	chartRequested, err := helm3.loadChart(chart, client.ChartPathOptions.LocateChart, settings)
+	if err != nil {
+		return nil, fmt.Errorf("load chart: %v", err)
+	}
+
+	r, err := client.Run(name, chartRequested, vals)
+	if err != nil {
+		return nil, fmt.Errorf("run: %v", err)
+	}
+	return r, nil
+}
+
+// Install returns the simulated release after installing
+func (helm3 *Helm3Client) Install(name, chart string, valueOpts *values.Options) (*helm3release.Release, error) {
+	conf := helm3.conf
+
+	args := []string{name, chart}
+
+	settings := helm3.settings
+
+	client := action.NewInstall(conf)
+	client.DryRun = true
+
+	name, chart, err := client.NameAndChart(args)
+	if err != nil {
+		return nil, err
+	}
+	client.ReleaseName = name
+
+	getters := getter.All(settings)
+	vals, err := valueOpts.MergeValues(getters)
+	if err != nil {
+		return nil, err
+	}
+
+	chartRequested, err := helm3.loadChart(chart, client.ChartPathOptions.LocateChart, settings)
+	if err != nil {
+		return nil, err
+	}
+
+	client.Namespace = helm3.getNamespace()
+	return client.Run(chartRequested, vals)
+}
+
+//func (helm3 *Helm3Client) kubeConfig() genericclioptions.RESTClientGetter {
+//	if helm3.config == nil {
+//		settings := helm3.settings
+//		helm3.config = kube.GetConfig(settings.KubeConfig, settings.KubeContext, settings.Namespace)
+//	}
+//	return helm3.config
+//}
+//
+func (helm3 *Helm3Client) getNamespace() string {
+	if helm3.settings.Namespace != "" {
+		return helm3.settings.Namespace
+	}
+
+	//if ns, _, err := cli.kubeConfig().ToRawKubeConfigLoader().Namespace(); err == nil {
+	//	return ns
+	//}
+	return "default"
+}
+
+func (helm3 *Helm3Client) loadChart(chart string, locateChart func(name string, settings *cli.EnvSettings) (string, error), settings *cli.EnvSettings) (*chart.Chart, error) {
+	chartPath, err := locateChart(chart, settings)
+	if err != nil {
+		return nil, fmt.Errorf("locate chart: %v", err)
+	}
+
+	debug("CHART PATH: %s\n", chartPath)
+
+	// Check chart dependencies to make sure all are present in /charts
+	chartRequested, err := loader.Load(chartPath)
+	if err != nil {
+		return nil, fmt.Errorf("load: %v", err)
+	}
+
+	validInstallableChart, checkErr := isChartInstallable(chartRequested)
+	if !validInstallableChart {
+		return nil, fmt.Errorf("invalid chart: checkErr=%v, err=%v", checkErr, err)
+	}
+
+	return chartRequested, nil
+}
+
+// isChartInstallable validates if a chart can be installed
+//
+// Application chart type is only installable
+func isChartInstallable(ch *chart.Chart) (bool, error) {
+	switch ch.Metadata.Type {
+	case "", "application":
+		return true, nil
+	}
+	return false, errors.Errorf("%s charts are not installable", ch.Metadata.Type)
+}
+
+func debug(msg string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, msg, args...)
+}
+
+func initActionConfig(actionConfig *action.Configuration, allNamespaces bool) {
+	kc := kube.New(kubeConfig())
+	kc.Log = debug
+
+	clientset, err := kc.Factory.KubernetesClientSet()
+	if err != nil {
+		// TODO return error
+		log.Fatal(err)
+	}
+	var namespace string
+	if !allNamespaces {
+		namespace = getNamespace()
+	}
+
+	var store *storage.Storage
+	switch os.Getenv("HELM_DRIVER") {
+	case "secret", "secrets", "":
+		d := driver.NewSecrets(clientset.CoreV1().Secrets(namespace))
+		d.Log = debug
+		store = storage.Init(d)
+	case "configmap", "configmaps":
+		d := driver.NewConfigMaps(clientset.CoreV1().ConfigMaps(namespace))
+		d.Log = debug
+		store = storage.Init(d)
+	case "memory":
+		d := driver.NewMemory()
+		store = storage.Init(d)
+	default:
+		// Not sure what to do here.
+		panic("Unknown driver in HELM_DRIVER: " + os.Getenv("HELM_DRIVER"))
+	}
+
+	actionConfig.RESTClientGetter = kubeConfig()
+	actionConfig.KubeClient = kc
+	actionConfig.Releases = store
+	actionConfig.Log = debug
+}
+
+func getNamespace() string {
+	if envSettings.Namespace != "" {
+		return envSettings.Namespace
+	}
+
+	if ns, _, err := kubeConfig().ToRawKubeConfigLoader().Namespace(); err == nil {
+		return ns
+	}
+	return "default"
+}
+
+func kubeConfig() genericclioptions.RESTClientGetter {
+	configOnce.Do(func() {
+		config = kube.GetConfig(settings.KubeConfig, settings.KubeContext, envSettings.Namespace)
+	})
+	return config
+}

cmd/upgrade.go

@@ -9,6 +9,8 @@ import (
 	"github.com/spf13/cobra"
 	"k8s.io/helm/pkg/helm"
 
+	"helm.sh/helm/pkg/action"
+
 	"github.com/databus23/helm-diff/diff"
 	"github.com/databus23/helm-diff/manifest"
 )
@@ -18,6 +20,7 @@ type diffCmd struct {
 	chart            string
 	chartVersion     string
 	client           helm.Interface
+	v3conf           *action.Configuration
 	detailedExitCode bool
 	devel            bool
 	namespace        string // namespace to assume the release to be installed into. Defaults to the current kube config namespace.
@@ -97,6 +100,13 @@ func newChartCommand() *cobra.Command {
 
 }
 
+func isHelm3() bool {
+	// See the followings. TILLER_HOST is helm2-only plugin env
+	// Helm 2: https://github.com/helm/helm/blob/7cad59091a9451b2aa4f95aa882ea27e6b195f98/pkg/plugin/plugin.go#L175-L192
+	// Helm 3: https://github.com/helm/helm/blob/5cb923eecbe80d1ad76399aee234717c11931d9a/pkg/plugin/plugin.go#L221-L232
+	return os.Getenv("TILLER_HOST") == ""
+}
+
 func (d *diffCmd) run() error {
 	if d.chartVersion == "" && d.devel {
 		d.chartVersion = ">0.0.0-0"
@@ -116,6 +126,10 @@ func (d *diffCmd) run() error {
 		return err
 	}
 
+	if isHelm3() {
+		return helm3Run(d, chartPath)
+	}
+
 	releaseResponse, err := d.client.ReleaseContent(d.release)
 
 	var newInstall bool