handle watch errors everywhere

pkg/api/errors/errors.go

@@ -21,6 +21,7 @@ import (
 	"net/http"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 )
 
 // statusError is an error intended for consumption by a REST API server.
@@ -38,6 +39,16 @@ func (e *statusError) Status() api.Status {
 	return e.status
 }
 
+// FromObject generates an statusError from an api.Status, if that is the type of obj; otherwise,
+// returns an error created by fmt.Errorf.
+func FromObject(obj runtime.Object) error {
+	switch t := obj.(type) {
+	case *api.Status:
+		return &statusError{*t}
+	}
+	return fmt.Errorf("unexpected object: %v", obj)
+}
+
 // NewNotFound returns a new error which indicates that the resource of the kind and the name was not found.
 func NewNotFound(kind, name string) error {
 	return &statusError{api.Status{

pkg/api/errors/errors_test.go

@@ -23,6 +23,7 @@ import (
 	"testing"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 )
 
 func TestErrorNew(t *testing.T) {
@@ -131,3 +132,23 @@ func Test_reasonForError(t *testing.T) {
 		t.Errorf("unexpected reason type: %#v", a)
 	}
 }
+
+type TestType struct{}
+
+func (*TestType) IsAnAPIObject() {}
+
+func TestFromObject(t *testing.T) {
+	table := []struct {
+		obj     runtime.Object
+		message string
+	}{
+		{&api.Status{Message: "foobar"}, "foobar"},
+		{&TestType{}, "unexpected object: &{}"},
+	}
+
+	for _, item := range table {
+		if e, a := item.message, FromObject(item.obj).Error(); e != a {
+			t.Errorf("Expected %v, got %v", e, a)
+		}
+	}
+}