Do not automatically decode runtime.RawExtension

Make clients opt in to decoding objects that are stored
in the generic api.List object by invoking runtime.DecodeList()
with a set of schemes. Makes it easier to handle unknown
schema objects because decoding is in the control of the code.

Add runtime.Unstructured, which is a simple in memory
representation of an external object.

pkg/runtime/helper_test.go

@@ -21,6 +21,7 @@ import (
 	"testing"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	_ "github.com/GoogleCloudPlatform/kubernetes/pkg/api/v1beta3"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 
@@ -132,6 +133,22 @@ func TestExtractListOfValuePtrs(t *testing.T) {
 	}
 }
 
+func TestDecodeList(t *testing.T) {
+	pl := &api.List{
+		Items: []runtime.Object{
+			&api.Pod{ObjectMeta: api.ObjectMeta{Name: "1"}},
+			&runtime.Unknown{TypeMeta: runtime.TypeMeta{Kind: "Pod", APIVersion: "v1beta3"}, RawJSON: []byte(`{"kind":"Pod","apiVersion":"v1beta3","metadata":{"name":"test"}}`)},
+			&runtime.Unstructured{TypeMeta: runtime.TypeMeta{Kind: "Foo", APIVersion: "Bar"}, Object: map[string]interface{}{"test": "value"}},
+		},
+	}
+	if errs := runtime.DecodeList(pl.Items, api.Scheme); len(errs) != 0 {
+		t.Fatalf("unexpected error %v", errs)
+	}
+	if pod, ok := pl.Items[1].(*api.Pod); !ok || pod.Name != "test" {
+		t.Errorf("object not converted: %#v", pl.Items[1])
+	}
+}
+
 func TestSetList(t *testing.T) {
 	pl := &api.PodList{}
 	list := []runtime.Object{