From 9bb0d33a3f3e53cfc3516aa715eb48e3f1efd1e2 Mon Sep 17 00:00:00 2001
From: Daniel Smith <dbsmith@google.com>
Date: Fri, 7 Nov 2014 14:41:59 -0800
Subject: [PATCH] Fix kubectl -template to be versioned

---
 pkg/kubectl/resource_printer.go      | 49 ++++++++++++++++------------
 pkg/kubectl/resource_printer_test.go | 25 ++++++++++++--
 2 files changed, 51 insertions(+), 23 deletions(-)

diff --git a/pkg/kubectl/resource_printer.go b/pkg/kubectl/resource_printer.go
index ab95e5adb72..1fa60a51dd2 100644
--- a/pkg/kubectl/resource_printer.go
+++ b/pkg/kubectl/resource_printer.go
@@ -28,6 +28,7 @@ import (
 	"text/template"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/latest"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 	"github.com/golang/glog"
@@ -45,35 +46,26 @@ func GetPrinter(format, templateFile string, defaultPrinter ResourcePrinter) (Re
 	case "yaml":
 		printer = &YAMLPrinter{}
 	case "template":
-		var data []byte
 		if len(templateFile) == 0 {
 			return nil, false, fmt.Errorf("template format specified but no template given")
 		}
-		tmpl, err := template.New("output").Parse(templateFile)
+		var err error
+		printer, err = NewTemplatePrinter([]byte(templateFile))
 		if err != nil {
-			return nil, false, fmt.Errorf("error parsing template %s, %v\n", string(data), err)
-		}
-		printer = &TemplatePrinter{
-			Template: tmpl,
+			return nil, false, fmt.Errorf("error parsing template %s, %v\n", templateFile, err)
 		}
 	case "templatefile":
-		var data []byte
-		if len(templateFile) > 0 {
-			var err error
-			data, err = ioutil.ReadFile(templateFile)
-			if err != nil {
-				return nil, false, fmt.Errorf("error reading template %s, %v\n", templateFile, err)
-			}
-		} else {
+		if len(templateFile) == 0 {
 			return nil, false, fmt.Errorf("templatefile format specified but no template file given")
 		}
-		tmpl, err := template.New("output").Parse(string(data))
+		data, err := ioutil.ReadFile(templateFile)
+		if err != nil {
+			return nil, false, fmt.Errorf("error reading template %s, %v\n", templateFile, err)
+		}
+		printer, err = NewTemplatePrinter(data)
 		if err != nil {
 			return nil, false, fmt.Errorf("error parsing template %s, %v\n", string(data), err)
 		}
-		printer = &TemplatePrinter{
-			Template: tmpl,
-		}
 	case "":
 		printer = defaultPrinter
 		versioned = false
@@ -323,12 +315,29 @@ func (h *HumanReadablePrinter) PrintObj(obj runtime.Object, output io.Writer) er
 
 // TemplatePrinter is an implementation of ResourcePrinter which formats data with a Go Template.
 type TemplatePrinter struct {
-	Template *template.Template
+	template *template.Template
+}
+
+func NewTemplatePrinter(tmpl []byte) (*TemplatePrinter, error) {
+	t, err := template.New("output").Parse(string(tmpl))
+	if err != nil {
+		return nil, err
+	}
+	return &TemplatePrinter{t}, nil
 }
 
 // PrintObj formats the obj with the Go Template.
 func (t *TemplatePrinter) PrintObj(obj runtime.Object, w io.Writer) error {
-	return t.Template.Execute(w, obj)
+	data, err := latest.Codec.Encode(obj)
+	if err != nil {
+		return err
+	}
+	outObj := map[string]interface{}{}
+	err = json.Unmarshal(data, &outObj)
+	if err != nil {
+		return err
+	}
+	return t.template.Execute(w, outObj)
 }
 
 func tabbedString(f func(*tabwriter.Writer) error) (string, error) {
diff --git a/pkg/kubectl/resource_printer_test.go b/pkg/kubectl/resource_printer_test.go
index 5cf4aacee00..fc7c6b6bd8d 100644
--- a/pkg/kubectl/resource_printer_test.go
+++ b/pkg/kubectl/resource_printer_test.go
@@ -86,14 +86,17 @@ func TestPrintYAML(t *testing.T) {
 
 func TestPrintTemplate(t *testing.T) {
 	buf := bytes.NewBuffer([]byte{})
-	printer, versioned, err := GetPrinter("template", "{{ .Name }}", nil)
+	printer, versioned, err := GetPrinter("template", "{{.id}}", nil)
 	if err != nil {
-		t.Errorf("unexpected error: %#v", err)
+		t.Fatalf("unexpected error: %#v", err)
 	}
 	if !versioned {
 		t.Errorf("printer should be versioned")
 	}
-	printer.PrintObj(&api.Pod{ObjectMeta: api.ObjectMeta{Name: "foo"}}, buf)
+	err = printer.PrintObj(&api.Pod{ObjectMeta: api.ObjectMeta{Name: "foo"}}, buf)
+	if err != nil {
+		t.Fatalf("unexpected error: %#v", err)
+	}
 	if buf.String() != "foo" {
 		t.Errorf("unexpected output: %s", buf.String())
 	}
@@ -204,3 +207,19 @@ func TestUnknownTypePrinting(t *testing.T) {
 		t.Errorf("An error was expected from printing unknown type")
 	}
 }
+
+func TestTemplateEmitsVersionedObjects(t *testing.T) {
+	// kind is always blank in memory and set on the wire
+	printer, err := NewTemplatePrinter([]byte(`{{.kind}}`))
+	if err != nil {
+		t.Fatalf("tmpl fail: %v", err)
+	}
+	buffer := &bytes.Buffer{}
+	err = printer.PrintObj(&api.Pod{}, buffer)
+	if err != nil {
+		t.Fatalf("print fail: %v", err)
+	}
+	if e, a := "Pod", string(buffer.Bytes()); e != a {
+		t.Errorf("Expected %v, got %v", e, a)
+	}
+}