Adding checks

Change-Id: Ib0fcc6cdaec98de074804c64b8b381e043f21215
diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index 157e984..3609ee2 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -12,8 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# docker build -t xosproject/kubernetes-synchronizer:candidate -f Dockerfile.synchronizer .
+
 # xosproject/kubernetes-synchronizer
-FROM xosproject/xos-synchronizer-base:2.0.0
+FROM xosproject/xos-synchronizer-base:master
 
 COPY xos/synchronizer /opt/xos/synchronizers/kubernetes
 COPY VERSION /opt/xos/synchronizers/kubernetes/
diff --git a/xos/synchronizer/pull_steps/pull_pods.py b/xos/synchronizer/pull_steps/pull_pods.py
index 89c970b..0fe0fc0 100644
--- a/xos/synchronizer/pull_steps/pull_pods.py
+++ b/xos/synchronizer/pull_steps/pull_pods.py
@@ -131,7 +131,7 @@
             return None
 
         slice_name = controller.metadata.name
-        if hasattr(controller.metadata, "labels"):
+        if hasattr(controller.metadata, "labels") and controller.metadata.labels is not None:
             if "xos_slice_name" in controller.metadata.labels:
                 # Someone has labeled the controller with an xos slice name. Use it.
                 slice_name = controller.metadata.labels["xos_slice_name"]
@@ -198,7 +198,7 @@
             # TODO(smbaker): Assumes all containers in a pod use the same image. Valid assumption for now?
             container = containers[0]
             if ":" in container.image:
-                (name, tag) = container.image.split(":")
+                (name, tag) = container.image.rsplit(":", 1)
             else:
                 # Is assuming a default necessary?
                 name = container.image