chore: add e2e test case for helm template with oci based helm chart

Signed-off-by: Tsubasa Nagasawa <toversus2357@gmail.com>

test/e2e/template/helmfile/snapshot_test.go

@@ -1,6 +1,7 @@
 package helmfile
 
 import (
+	"bufio"
 	"context"
 	"fmt"
 	"os"
@@ -16,6 +17,12 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
+type ociChart struct {
+	name    string
+	version string
+	digest  string
+}
+
 func TestHelmfileTemplateWithBuildCommand(t *testing.T) {
 	type Config struct {
 		LocalDockerRegistry struct {
@@ -95,6 +102,8 @@ func TestHelmfileTemplateWithBuildCommand(t *testing.T) {
 				}
 			})
 
+			// ociCharts holds a list of chart name, version and digest distributed by local oci registry.
+			ociCharts := []ociChart{}
 			// If localDockerRegistry.enabled is set to `true`,
 			// run the docker registry v2 and push the test charts to the registry
 			// so that it can be accessed by helm and helmfile as a oci registry based chart repository.
@@ -126,7 +135,20 @@ func TestHelmfileTemplateWithBuildCommand(t *testing.T) {
 						t.Fatalf("%s is not a directory", c)
 					}
 					tgzFile := execHelmPackage(t, chartPath)
-					_ = execHelm(t, "push", tgzFile, fmt.Sprintf("oci://localhost:%d/myrepo", hostPort))
+
+					// Extract chart version from the name of chart package archival
+					chartName := c.Name()
+					chartNameWithVersion := strings.TrimSuffix(filepath.Base(tgzFile), filepath.Ext(tgzFile))
+					chartVersion := strings.TrimPrefix(chartNameWithVersion, fmt.Sprintf("%s-", chartName))
+
+					chartDigest, err := execHelmPush(t, tgzFile, fmt.Sprintf("oci://localhost:%d/myrepo", hostPort))
+					require.NoError(t, err, "Unable to run helm push to local registry: %v", err)
+
+					ociCharts = append(ociCharts, ociChart{
+						name:    chartName,
+						version: chartVersion,
+						digest:  chartDigest,
+					})
 				}
 			}
 
@@ -155,6 +177,37 @@ func TestHelmfileTemplateWithBuildCommand(t *testing.T) {
 
 			gotStr := string(got)
 			gotStr = strings.ReplaceAll(gotStr, fmt.Sprintf("chart=%s", wd), "chart=$WD")
+			// OCI based helm charts are pulled and exported under temporary directory.
+			// We are not sure the exact name of the temporary directory generated by helmfile,
+			// so redact its base directory name with $TMP.
+			if config.LocalDockerRegistry.Enabled {
+				var releaseName, chartPath string
+				sc := bufio.NewScanner(strings.NewReader(gotStr))
+				for sc.Scan() {
+					if !strings.HasPrefix(sc.Text(), "Templating ") {
+						continue
+					}
+					releaseChartStr := strings.TrimPrefix(sc.Text(), "Templating ")
+					releaseChartParts := strings.Split(releaseChartStr, ", ")
+					if len(releaseChartParts) != 2 {
+						t.Fatal("Found unexpected log output of templating oci based helm chart, want=\"Templating release=<release_name>, chart=<chart_name>\"")
+					}
+					releaseNamePart, chartPathPart := releaseChartParts[0], releaseChartParts[1]
+					releaseName = strings.TrimPrefix(releaseNamePart, "release=")
+					chartPath = chartPathPart
+				}
+				for _, ociChart := range ociCharts {
+					chartPathWithoutTempDirBase := fmt.Sprintf("/%s/%s/%s/%s", releaseName, ociChart.name, ociChart.version, ociChart.name)
+					var chartPathBase string
+					if strings.HasSuffix(chartPath, chartPathWithoutTempDirBase) {
+						chartPathBase = strings.TrimSuffix(chartPath, chartPathWithoutTempDirBase)
+					}
+					if len(chartPathBase) != 0 {
+						gotStr = strings.ReplaceAll(gotStr, chartPathBase, "chart=$TMP")
+					}
+					gotStr = strings.ReplaceAll(gotStr, fmt.Sprintf("Digest: %s", ociChart.digest), "Digest: $DIGEST")
+				}
+			}
 
 			if stat, _ := os.Stat(outputFile); stat != nil {
 				want, err := os.ReadFile(outputFile)
@@ -191,6 +244,21 @@ func execHelmPackage(t *testing.T, localChart string) string {
 	return strings.TrimSpace(tgzAbsPath)
 }
 
+// execHelmPush pushes helm package to oci based helm repository,
+// then returns its digest.
+func execHelmPush(t *testing.T, tgzPath, remoteUrl string) (string, error) {
+	t.Helper()
+
+	out := execHelm(t, "push", tgzPath, remoteUrl)
+	sc := bufio.NewScanner(strings.NewReader(out))
+	for sc.Scan() {
+		if strings.HasPrefix(sc.Text(), "Digest:") {
+			return strings.TrimPrefix(sc.Text(), "Digest: "), nil
+		}
+	}
+	return "", fmt.Errorf("Unable to find chart digest from output string of helm push")
+}
+
 func execHelm(t *testing.T, args ...string) string {
 	t.Helper()
 

test/e2e/template/helmfile/testdata/snapshot/oci_chart_pull/config.yaml

@@ -0,0 +1,6 @@
+localDockerRegistry:
+  enabled: true
+  port: 5000
+chartifyTempDir: temp2
+helmfileArgs:
+- template

test/e2e/template/helmfile/testdata/snapshot/oci_chart_pull/input.yaml

@@ -0,0 +1,19 @@
+repositories:
+- name: myrepo
+  url: localhost:5000/myrepo
+  oci: true
+
+releases:
+- name: foo
+  chart: myrepo/raw
+  version: 0.1.0
+  values:
+  - templates:
+    - |
+      apiVersion: v1
+      kind: ConfigMap
+      metadata:
+        name: {{`{{ .Release.Name }}`}}
+        namespace: {{`{{ .Release.Namespace }}`}}
+      data:
+        foo: FOO

test/e2e/template/helmfile/testdata/snapshot/oci_chart_pull/output.yaml

@@ -0,0 +1,15 @@
+Pulling localhost:5000/myrepo/raw:0.1.0
+Pulled: localhost:5000/myrepo/raw:0.1.0
+Digest: $DIGEST
+
+Templating release=foo, chart=$TMP/foo/raw/0.1.0/raw
+---
+# Source: raw/templates/resources.yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo
+  namespace: default
+data:
+  foo: FOO
+