Merge pull request #2350 from eicnix/master

Added "tpl" template function

pkg/engine/engine.go

@@ -37,7 +37,8 @@ type Engine struct {
 	FuncMap template.FuncMap
 	// If strict is enabled, template rendering will fail if a template references
 	// a value that was not passed in.
-	Strict bool
+	Strict           bool
+	CurrentTemplates map[string]renderable
 }
 
 // New creates a new Go template Engine instance.
@@ -65,7 +66,9 @@ func New() *Engine {
 //	- "include": This is late-bound in Engine.Render(). The version
 //	   included in the FuncMap is a placeholder.
 //      - "required": This is late-bound in Engine.Render(). The version
-//	   included in thhe FuncMap is a placeholder.
+//	   included in the FuncMap is a placeholder.
+//      - "tpl": This is late-bound in Engine.Render(). The version
+//	   included in the FuncMap is a placeholder.
 func FuncMap() template.FuncMap {
 	f := sprig.TxtFuncMap()
 	delete(f, "env")
@@ -84,6 +87,7 @@ func FuncMap() template.FuncMap {
 		// integrity of the linter.
 		"include":  func(string, interface{}) string { return "not implemented" },
 		"required": func(string, interface{}) interface{} { return "not implemented" },
+		"tpl":      func(string, interface{}) interface{} { return "not implemented" },
 	}
 
 	for k, v := range extra {
@@ -115,6 +119,7 @@ func FuncMap() template.FuncMap {
 func (e *Engine) Render(chrt *chart.Chart, values chartutil.Values) (map[string]string, error) {
 	// Render the charts
 	tmap := allTemplates(chrt, values)
+	e.CurrentTemplates = tmap
 	return e.render(tmap)
 }
 
@@ -159,6 +164,23 @@ func (e *Engine) alterFuncMap(t *template.Template) template.FuncMap {
 		return val, nil
 	}
 
+	// Add the 'tpl' function here
+	funcMap["tpl"] = func(tpl string, vals chartutil.Values) (string, error) {
+		r := renderable{
+			tpl:  tpl,
+			vals: vals,
+		}
+
+		templates := map[string]renderable{}
+		templates["aaa_template"] = r
+
+		result, err := e.render(templates)
+		if err != nil {
+			return "", fmt.Errorf("Error during tpl function execution for %q: %s", tpl, err.Error())
+		}
+		return result["aaa_template"], nil
+	}
+
 	return funcMap
 }
 
@@ -187,7 +209,7 @@ func (e *Engine) render(tpls map[string]renderable) (map[string]string, error) {
 	keys := sortTemplates(tpls)
 
 	files := []string{}
-	//for fname, r := range tpls {
+
 	for _, fname := range keys {
 		r := tpls[fname]
 		t = t.New(fname).Funcs(funcMap)
@@ -197,6 +219,17 @@ func (e *Engine) render(tpls map[string]renderable) (map[string]string, error) {
 		files = append(files, fname)
 	}
 
+	// Adding the engine's currentTemplates to the template context
+	// so they can be referenced in the tpl function
+	for fname, r := range e.CurrentTemplates {
+		if t.Lookup(fname) == nil {
+			t = t.New(fname).Funcs(funcMap)
+			if _, err := t.Parse(r.tpl); err != nil {
+				return map[string]string{}, fmt.Errorf("parse error in %q: %s", fname, err)
+			}
+		}
+	}
+
 	rendered := make(map[string]string, len(files))
 	var buf bytes.Buffer
 	for _, file := range files {

pkg/engine/engine_test.go

@@ -80,7 +80,7 @@ func TestFuncMap(t *testing.T) {
 	}
 
 	// Test for Engine-specific template functions.
-	expect := []string{"include", "required", "toYaml", "fromYaml", "toToml", "toJson", "fromJson"}
+	expect := []string{"include", "required", "tpl", "toYaml", "fromYaml", "toToml", "toJson", "fromJson"}
 	for _, f := range expect {
 		if _, ok := fns[f]; !ok {
 			t.Errorf("Expected add-on function %q", f)
@@ -476,4 +476,91 @@ func TestAlterFuncMap(t *testing.T) {
 		t.Errorf("Expected %q, got %q (%v)", expectNum, gotNum, outReq)
 	}
 
+	tplChart := &chart.Chart{
+		Metadata: &chart.Metadata{Name: "TplFunction"},
+		Templates: []*chart.Template{
+			{Name: "templates/base", Data: []byte(`Evaluate tpl {{tpl "Value: {{ .Values.value}}" .}}`)},
+		},
+		Values:       &chart.Config{Raw: ``},
+		Dependencies: []*chart.Chart{},
+	}
+
+	tplValues := chartutil.Values{
+		"Values": chartutil.Values{
+			"value": "myvalue",
+		},
+		"Chart": tplChart.Metadata,
+		"Release": chartutil.Values{
+			"Name": "TestRelease",
+		},
+	}
+
+	outTpl, err := New().Render(tplChart, tplValues)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expectTplStr := "Evaluate tpl Value: myvalue"
+	if gotStrTpl := outTpl["TplFunction/templates/base"]; gotStrTpl != expectTplStr {
+		t.Errorf("Expected %q, got %q (%v)", expectTplStr, gotStrTpl, outTpl)
+	}
+
+	tplChartWithFunction := &chart.Chart{
+		Metadata: &chart.Metadata{Name: "TplFunction"},
+		Templates: []*chart.Template{
+			{Name: "templates/base", Data: []byte(`Evaluate tpl {{tpl "Value: {{ .Values.value | quote}}" .}}`)},
+		},
+		Values:       &chart.Config{Raw: ``},
+		Dependencies: []*chart.Chart{},
+	}
+
+	tplValuesWithFunction := chartutil.Values{
+		"Values": chartutil.Values{
+			"value": "myvalue",
+		},
+		"Chart": tplChartWithFunction.Metadata,
+		"Release": chartutil.Values{
+			"Name": "TestRelease",
+		},
+	}
+
+	outTplWithFunction, err := New().Render(tplChartWithFunction, tplValuesWithFunction)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expectTplStrWithFunction := "Evaluate tpl Value: \"myvalue\""
+	if gotStrTplWithFunction := outTplWithFunction["TplFunction/templates/base"]; gotStrTplWithFunction != expectTplStrWithFunction {
+		t.Errorf("Expected %q, got %q (%v)", expectTplStrWithFunction, gotStrTplWithFunction, outTplWithFunction)
+	}
+
+	tplChartWithInclude := &chart.Chart{
+		Metadata: &chart.Metadata{Name: "TplFunction"},
+		Templates: []*chart.Template{
+			{Name: "templates/base", Data: []byte(`{{ tpl "{{include ` + "`" + `TplFunction/templates/_partial` + "`" + ` .  | quote }}" .}}`)},
+			{Name: "templates/_partial", Data: []byte(`{{.Release.Name}}`)},
+		},
+		Values:       &chart.Config{Raw: ``},
+		Dependencies: []*chart.Chart{},
+	}
+	tplValueWithInclude := chartutil.Values{
+		"Values": chartutil.Values{
+			"value": "myvalue",
+		},
+		"Chart": tplChartWithInclude.Metadata,
+		"Release": chartutil.Values{
+			"Name": "TestRelease",
+		},
+	}
+
+	outTplWithInclude, err := New().Render(tplChartWithInclude, tplValueWithInclude)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expectedTplStrWithInclude := "\"TestRelease\""
+	if gotStrTplWithInclude := outTplWithInclude["TplFunction/templates/base"]; gotStrTplWithInclude != expectedTplStrWithInclude {
+		t.Errorf("Expected %q, got %q (%v)", expectedTplStrWithInclude, gotStrTplWithInclude, outTplWithInclude)
+	}
+
 }