feat: Remove dependency references (#148)

* feat: Remove dependency references

Signed-off-by: Miguel Martinez Trivino <[email protected]>

Author: Miguel Martínez Triviño

internal/testdata/applyoutput/3-levels-chart/Chart.yaml

@@ -1,5 +1,12 @@
 apiVersion: v2
 appVersion: 1.16.0
+dependencies:
+- name: subchart-1
+  repository: ""
+  version: 0.1.0
+- name: subchart-2
+  repository: ""
+  version: 0.1.0
 description: A Helm chart for Kubernetes
 name: 3-levels-chart
 type: application

internal/testdata/applyoutput/3-levels-chart/charts/subchart-1-0.1.0.tgz

@@ -642,9 +642,33 @@ func modifyChart(originalChart *chart.Chart, actions []*internal.RewriteAction,
 		}
 	}
 
+	// Remove dependencies references. The chart will still work because it has the dependencies vendored in charts/
+	// This just prevents users from overriding the relocation overrides applied by this tool
+	if err := stripDependencyRefs(modifiedChart); err != nil {
+		return err
+	}
+
 	return saveChart(modifiedChart, toChartFilename)
 }
 
+// Remove dependency references in the Helm Chart so helm dep update is not available once the chart has been relocated
+// See https://github.com/vmware-tanzu/asset-relocation-tool-for-kubernetes/issues/142#issue-1124233145
+// Removes recursively the Chart.lock file and the dependencies reference inside Chart.yaml
+func stripDependencyRefs(c *chart.Chart) error {
+	// By setting this to nil, chart.Save will re-save the Chart.yaml and ignore the lock
+	c.Metadata.Dependencies = nil
+	c.Lock = nil
+
+	// Apply to sub-charts too
+	for _, dep := range c.Dependencies() {
+		if err := stripDependencyRefs(dep); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func saveChart(chart *chart.Chart, toChartFilename string) error {
 	cwd, _ := os.Getwd()
 	tempDir, err := ioutil.TempDir(cwd, "relok8s-*")

internal/testdata/applyoutput/3-levels-chart/charts/subchart-2-0.1.0.tgz

@@ -12,6 +12,8 @@ import (
 	"sort"
 	"testing"
 
+	"helm.sh/helm/v3/pkg/chartutil"
+
 	"helm.sh/helm/v3/pkg/chart"
 
 	"github.com/google/go-containerregistry/pkg/name"
@@ -736,3 +738,73 @@ func TestGroupChangesByChart(t *testing.T) {
 		t.Errorf("got=%v; want=%v", got, want)
 	}
 }
+
+// Check that a relocated Helm Chart does not contain information about their dependencies
+func TestStripDependencyRefs(t *testing.T) {
+	testChart, err := loader.Load(filepath.Join(fixturesRoot, "3-levels-chart"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(testChart.Metadata.Dependencies), 2; got != want {
+		t.Errorf("invalid number of dependencies, got=%d, want=%d", got, want)
+	}
+
+	if testChart.Lock == nil {
+		t.Error("Chart.lock file expected ")
+	}
+
+	firstLevelDeps := testChart.Dependencies()
+	// Sort dependencies since they come in arbitrary order
+	sortCharts(firstLevelDeps)
+
+	// Subchart1
+	if got, want := len(firstLevelDeps[0].Metadata.Dependencies), 1; got != want {
+		t.Errorf("invalid number of dependencies, got=%d, want=%d", got, want)
+	}
+
+	if firstLevelDeps[0].Lock == nil {
+		t.Error("Chart.lock file expected ")
+	}
+
+	// Strip dependencies and re-package chart
+	if err := stripDependencyRefs(testChart); err != nil {
+		t.Fatal(err)
+	}
+
+	tmpDir, err := os.MkdirTemp("", "external-tests-*")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Repackage chart
+	filename, err := chartutil.Save(testChart, tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Load from re-packaged version
+	modifiedChart, err := loader.Load(filename)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	firstLevelDeps = modifiedChart.Dependencies()
+	sortCharts(firstLevelDeps)
+
+	for _, c := range []*chart.Chart{modifiedChart, firstLevelDeps[0]} {
+		if got := len(c.Metadata.Dependencies); got != 0 {
+			t.Errorf("expected no dependencies got=%d", got)
+		}
+
+		if c.Lock != nil {
+			t.Error("Chart.lock file unexpected ")
+		}
+	}
+}
+
+func sortCharts(charts []*chart.Chart) {
+	sort.Slice(charts, func(i, j int) bool {
+		return charts[i].Name() < charts[j].Name()
+	})
+}

pkg/mover/chart.go

@@ -0,0 +1,9 @@
+dependencies:
+- name: subchart-1
+  repository: ""
+  version: 0.1.0
+- name: subchart-2
+  repository: ""
+  version: 0.1.0
+digest: sha256:a7493ea91a9ff512f9eb05db01b79fddaf56214ecf45c049d0d18f57363e93ef
+generated: "2022-02-17T16:27:12.34928543+01:00"

pkg/mover/chart_test.go

@@ -1,6 +1,11 @@
 apiVersion: v2
 name: 3-levels-chart
 description: A Helm chart for Kubernetes
+dependencies:
+  - name: subchart-1
+    version: 0.1.0
+  - name: subchart-2
+    version: 0.1.0
 
 # A chart can be either an 'application' or a 'library' chart.
 #

test/fixtures/3-levels-chart/Chart.lock

@@ -0,0 +1,6 @@
+dependencies:
+- name: subchart-3
+  repository: ""
+  version: 0.1.0
+digest: sha256:c8e962b6fdb2bc5929dcfbb964f24826400c00529754d0c6848bd6ad66ff960f
+generated: "2022-02-17T16:28:44.347503267+01:00"

test/fixtures/3-levels-chart/Chart.yaml

@@ -1,7 +1,9 @@
 apiVersion: v2
 name: subchart-1
 description: A Helm chart for Kubernetes
-
+dependencies:
+  - name: subchart-3
+    version: 0.1.0
 # A chart can be either an 'application' or a 'library' chart.
 #
 # Application charts are a collection of templates that can be packaged into versioned archives