Add "PrintErrorWithCauses" cmdutil helper

This patch adds a new helper function to cmd/util/helpers.go that
handles errors containing collections of causes and prints each cause in
a separate newline.

pkg/kubectl/cmd/set/helper.go

@@ -23,6 +23,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/errors"
+	kcmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
 	"k8s.io/kubernetes/pkg/kubectl/resource"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/util/strategicpatch"
@@ -59,6 +60,10 @@ func handlePodUpdateError(out io.Writer, err error, resource string) {
 			if all && match {
 				return
 			}
+		} else {
+			if ok := kcmdutil.PrintErrorWithCauses(err, out); ok {
+				return
+			}
 		}
 	}
 

pkg/kubectl/cmd/util/helpers.go

@@ -255,6 +255,26 @@ func MultilineError(prefix string, err error) string {
 	return fmt.Sprintf("%s%s\n", prefix, err)
 }
 
+// PrintErrorWithCauses prints an error's kind, name, and each of the error's causes in a new line.
+// The returned string will end with a newline.
+// Returns true if a case exists to handle the error type, or false otherwise.
+func PrintErrorWithCauses(err error, errOut io.Writer) bool {
+	switch t := err.(type) {
+	case *kerrors.StatusError:
+		errorDetails := t.Status().Details
+		if errorDetails != nil {
+			fmt.Fprintf(errOut, "error: %s %q is invalid\n\n", errorDetails.Kind, errorDetails.Name)
+			for _, cause := range errorDetails.Causes {
+				fmt.Fprintf(errOut, "* %s: %s\n", cause.Field, cause.Message)
+			}
+			return true
+		}
+	}
+
+	fmt.Fprintf(errOut, "error: %v\n", err)
+	return false
+}
+
 // MultipleErrors returns a newline delimited string containing
 // the prefix and referenced errors in standard form.
 func MultipleErrors(prefix string, errs []error) string {