feat(pkg/engine): expose subcharts scope in parent

Expose the scope (.Values, .Charts, .Releases etc.) of subcharts to the parent scope.

Signed-off-by: Valentin Flaux <vflaux@oui.sncf>

pkg/engine/engine.go

@@ -260,6 +260,7 @@ func (e Engine) renderWithReferences(tpls, referenceTpls map[string]renderable)
 		if err := t.ExecuteTemplate(&buf, filename, vals); err != nil {
 			return map[string]string{}, cleanupExecError(filename, err)
 		}
+		delete(vals, "Template")
 
 		// Work around the issue where Go will emit "<no value>" even if Options(missing=zero)
 		// is set. Since missing=error will never get here, we do not need to handle
@@ -344,13 +345,15 @@ func allTemplates(c *chart.Chart, vals chartutil.Values) map[string]renderable {
 //
 // As it recurses, it also sets the values to be appropriate for the template
 // scope.
-func recAllTpls(c *chart.Chart, templates map[string]renderable, vals chartutil.Values) {
+func recAllTpls(c *chart.Chart, templates map[string]renderable, vals chartutil.Values) map[string]interface{} {
+	subCharts := make(map[string]interface{})
 	next := map[string]interface{}{
 		"Chart":        c.Metadata,
 		"Files":        newFiles(c.Files),
 		"Release":      vals["Release"],
 		"Capabilities": vals["Capabilities"],
 		"Values":       make(chartutil.Values),
+		"Subcharts":    subCharts,
 	}
 
 	// If there is a {{.Values.ThisChart}} in the parent metadata,
@@ -362,7 +365,7 @@ func recAllTpls(c *chart.Chart, templates map[string]renderable, vals chartutil.
 	}
 
 	for _, child := range c.Dependencies() {
-		recAllTpls(child, templates, next)
+		subCharts[child.Name()] = recAllTpls(child, templates, next)
 	}
 
 	newParentID := c.ChartFullPath()
@@ -376,6 +379,8 @@ func recAllTpls(c *chart.Chart, templates map[string]renderable, vals chartutil.
 			basePath: path.Join(newParentID, "templates"),
 		}
 	}
+
+	return next
 }
 
 // isTemplateValid returns true if the template is valid for the chart type

pkg/engine/engine_test.go

@@ -384,6 +384,8 @@ func TestRenderNestedValues(t *testing.T) {
 	// Ensure namespacing rules are working.
 	deepestpath := "templates/inner.tpl"
 	checkrelease := "templates/release.tpl"
+	// Ensure subcharts scopes are working.
+	subchartspath := "templates/subcharts.tpl"
 
 	deepest := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "deepest"},
@@ -391,7 +393,7 @@ func TestRenderNestedValues(t *testing.T) {
 			{Name: deepestpath, Data: []byte(`And this same {{.Values.what}} that smiles {{.Values.global.when}}`)},
 			{Name: checkrelease, Data: []byte(`Tomorrow will be {{default "happy" .Release.Name }}`)},
 		},
-		Values: map[string]interface{}{"what": "milkshake"},
+		Values: map[string]interface{}{"what": "milkshake", "where": "here"},
 	}
 
 	inner := &chart.Chart{
@@ -399,7 +401,7 @@ func TestRenderNestedValues(t *testing.T) {
 		Templates: []*chart.File{
 			{Name: innerpath, Data: []byte(`Old {{.Values.who}} is still a-flyin'`)},
 		},
-		Values: map[string]interface{}{"who": "Robert"},
+		Values: map[string]interface{}{"who": "Robert", "what": "glasses"},
 	}
 	inner.AddDependency(deepest)
 
@@ -407,12 +409,14 @@ func TestRenderNestedValues(t *testing.T) {
 		Metadata: &chart.Metadata{Name: "top"},
 		Templates: []*chart.File{
 			{Name: outerpath, Data: []byte(`Gather ye {{.Values.what}} while ye may`)},
+			{Name: subchartspath, Data: []byte(`The glorious Lamp of {{.Subcharts.herrick.Subcharts.deepest.Values.where}}, the {{.Subcharts.herrick.Values.what}}`)},
 		},
 		Values: map[string]interface{}{
 			"what": "stinkweed",
 			"who":  "me",
 			"herrick": map[string]interface{}{
-				"who": "time",
+				"who":  "time",
+				"what": "Sun",
 			},
 		},
 	}
@@ -422,7 +426,8 @@ func TestRenderNestedValues(t *testing.T) {
 		"what": "rosebuds",
 		"herrick": map[string]interface{}{
 			"deepest": map[string]interface{}{
-				"what": "flower",
+				"what":  "flower",
+				"where": "Heaven",
 			},
 		},
 		"global": map[string]interface{}{
@@ -469,6 +474,11 @@ func TestRenderNestedValues(t *testing.T) {
 	if out[fullcheckrelease] != "Tomorrow will be dyin" {
 		t.Errorf("Unexpected release: %q", out[fullcheckrelease])
 	}
+
+	fullchecksubcharts := "top/" + subchartspath
+	if out[fullchecksubcharts] != "The glorious Lamp of Heaven, the Sun" {
+		t.Errorf("Unexpected subcharts: %q", out[fullchecksubcharts])
+	}
 }
 
 func TestRenderBuiltinValues(t *testing.T) {
@@ -488,6 +498,7 @@ func TestRenderBuiltinValues(t *testing.T) {
 		Metadata: &chart.Metadata{Name: "Troy"},
 		Templates: []*chart.File{
 			{Name: "templates/Aeneas", Data: []byte(`{{.Template.Name}}{{.Chart.Name}}{{.Release.Name}}`)},
+			{Name: "templates/Amata", Data: []byte(`{{.Subcharts.Latium.Chart.Name}} {{.Subcharts.Latium.Files.author | printf "%s"}}`)},
 		},
 	}
 	outer.AddDependency(inner)
@@ -510,6 +521,7 @@ func TestRenderBuiltinValues(t *testing.T) {
 	expects := map[string]string{
 		"Troy/charts/Latium/templates/Lavinia": "Troy/charts/Latium/templates/LaviniaLatiumAeneid",
 		"Troy/templates/Aeneas":                "Troy/templates/AeneasTroyAeneid",
+		"Troy/templates/Amata":                 "Latium Virgil",
 		"Troy/charts/Latium/templates/From":    "Virgil Aeneid",
 	}
 	for file, expect := range expects {