Use helm show chart to identify chart version

Signed-off-by: Felipe Santos <felipecassiors@gmail.com>

pkg/helmexec/exec.go

@@ -14,6 +14,8 @@ import (
 	"github.com/Masterminds/semver/v3"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
+	"gopkg.in/yaml.v3"
+	"helm.sh/helm/v3/pkg/chart"
 	"helm.sh/helm/v3/pkg/cli"
 	"helm.sh/helm/v3/pkg/plugin"
 
@@ -599,3 +601,21 @@ func resolveOciChart(ociChart string) (ociChartURL, ociChartTag string) {
 	ociChartURL = fmt.Sprintf("oci://%s", ociChart[:urlTagIndex])
 	return ociChartURL, ociChartTag
 }
+
+func (helm *execer) ShowChart(chartPath string) (chart.Metadata, error) {
+	if !helm.IsHelm3() {
+		// show chart command isn't supported in helm2
+		return chart.Metadata{}, fmt.Errorf("helm show isn't supported in helm2")
+	}
+	var helmArgs = []string{"show", "chart", chartPath}
+	out, error := helm.exec(helmArgs, map[string]string{}, nil)
+	if error != nil {
+		return chart.Metadata{}, error
+	}
+	var metadata chart.Metadata
+	error = yaml.Unmarshal(out, &metadata)
+	if error != nil {
+		return chart.Metadata{}, error
+	}
+	return metadata, nil
+}

pkg/helmexec/exec_test.go

@@ -1008,3 +1008,32 @@ func Test_resolveOciChart(t *testing.T) {
 		})
 	}
 }
+
+func Test_ShowChart(t *testing.T) {
+	helm2Runner := mockRunner{output: []byte("Client: v2.16.1+ge13bc94\n")}
+	helm := New("helm", false, NewLogger(os.Stdout, "info"), "dev", &helm2Runner)
+	_, err := helm.ShowChart("fake-chart")
+	if err == nil {
+		t.Error("helmexec.ShowChart() - helm show isn't supported in helm2")
+	}
+
+	showChartRunner := mockRunner{output: []byte("name: my-chart\nversion: 3.2.0\n")}
+	helm = &execer{
+		helmBinary:  "helm",
+		version:     *semver.MustParse("3.3.2"),
+		logger:      NewLogger(os.Stdout, "info"),
+		kubeContext: "dev",
+		runner:      &showChartRunner,
+	}
+
+	metadata, err := helm.ShowChart("my-chart")
+	if err != nil {
+		t.Errorf("helmexec.ShowChart() - unexpected error: %v", err)
+	}
+	if metadata.Name != "my-chart" {
+		t.Errorf("helmexec.ShowChart() - expected chart name was %s, received: %s", "my-chart", metadata.Name)
+	}
+	if metadata.Version != "3.2.0" {
+		t.Errorf("helmexec.ShowChart() - expected chart version was %s, received: %s", "3.2.0", metadata.Version)
+	}
+}

pkg/helmexec/helmexec.go

@@ -1,5 +1,7 @@
 package helmexec
 
+import "helm.sh/helm/v3/pkg/chart"
+
 // Version represents the version of helm
 type Version struct {
 	Major int
@@ -33,6 +35,7 @@ type Interface interface {
 	IsHelm3() bool
 	GetVersion() Version
 	IsVersionAtLeast(versionStr string) bool
+	ShowChart(chart string) (chart.Metadata, error)
 }
 
 type DependencyUpdater interface {