make rolling update check if the replication controller has been defaulted

pkg/kubectl/cmd/rollingupdate.go

@@ -26,6 +26,8 @@ import (
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/errors"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/v1"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/v1beta3"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubectl"
 	cmdutil "github.com/GoogleCloudPlatform/kubernetes/pkg/kubectl/cmd/util"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubectl/resource"
@@ -143,6 +145,7 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 	}
 
 	var keepOldName bool
+	var replicasDefaulted bool
 
 	mapper, typer := f.Object()
 
@@ -151,12 +154,12 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		if err != nil {
 			return err
 		}
-		obj, err := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand()).
+		request := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand()).
 			Schema(schema).
 			NamespaceParam(cmdNamespace).RequireNamespace().
 			FilenameParam(filename).
-			Do().
-			Object()
+			Do()
+		obj, err := request.Object()
 		if err != nil {
 			return err
 		}
@@ -177,6 +180,12 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 			glog.V(4).Infof("Object %#v is not a ReplicationController", obj)
 			return cmdutil.UsageError(cmd, "%s does not specify a valid ReplicationController", filename)
 		}
+		infos, err := request.Infos()
+		if err != nil || len(infos) != 1 {
+			glog.V(2).Infof("was not able to recover adequate information to discover if .spec.replicas was defaulted")
+		} else {
+			replicasDefaulted = isReplicasDefaulted(infos[0])
+		}
 	}
 	// If the --image option is specified, we need to create a new rc with at least one different selector
 	// than the old rc. This selector is the hash of the rc, which will differ because the new rc has a
@@ -228,7 +237,7 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 			filename, oldName)
 	}
 	// TODO: handle scales during rolling update
-	if newRc.Spec.Replicas == 0 {
+	if replicasDefaulted {
 		newRc.Spec.Replicas = oldRc.Spec.Replicas
 	}
 	if dryrun {
@@ -283,3 +292,21 @@ func findNewName(args []string, oldRc *api.ReplicationController) string {
 	}
 	return ""
 }
+
+func isReplicasDefaulted(info *resource.Info) bool {
+	if info == nil || info.VersionedObject == nil {
+		// was unable to recover versioned info
+		return false
+	}
+	switch info.Mapping.APIVersion {
+	case "v1":
+		if rc, ok := info.VersionedObject.(*v1.ReplicationController); ok {
+			return rc.Spec.Replicas == nil
+		}
+	case "v1beta3":
+		if rc, ok := info.VersionedObject.(*v1beta3.ReplicationController); ok {
+			return rc.Spec.Replicas == nil
+		}
+	}
+	return false
+}

pkg/kubectl/resource/mapper.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"reflect"
 
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/meta"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/yaml"
@@ -64,13 +65,19 @@ func (m *Mapper) InfoForData(data []byte, source string) (*Info, error) {
 	name, _ := mapping.MetadataAccessor.Name(obj)
 	namespace, _ := mapping.MetadataAccessor.Namespace(obj)
 	resourceVersion, _ := mapping.MetadataAccessor.ResourceVersion(obj)
-	return &Info{
-		Mapping:   mapping,
-		Client:    client,
-		Namespace: namespace,
-		Name:      name,
-		Source:    source,
 
+	var versionedObject interface{}
+
+	if vo, _, _, err := api.Scheme.Raw().DecodeToVersionedObject(data); err == nil {
+		versionedObject = vo
+	}
+	return &Info{
+		Mapping:         mapping,
+		Client:          client,
+		Namespace:       namespace,
+		Name:            name,
+		Source:          source,
+		VersionedObject: versionedObject,
 		Object:          obj,
 		ResourceVersion: resourceVersion,
 	}, nil

pkg/kubectl/resource/visitor.go

@@ -69,6 +69,10 @@ type Info struct {
 	// Optional, Source is the filename or URL to template file (.json or .yaml),
 	// or stdin to use to handle the resource
 	Source string
+	// Optional, this is the provided object in a versioned type before defaulting
+	// and conversions into its corresponding internal type. This is useful for
+	// reflecting on user intent which may be lost after defaulting and conversions.
+	VersionedObject interface{}
 	// Optional, this is the most recent value returned by the server if available
 	runtime.Object
 	// Optional, this is the most recent resource version the server knows about for