Ensure TTL is not cleared in possible edge cases

pkg/tools/etcd_helper.go

@@ -556,14 +556,21 @@ func (h *EtcdHelper) GuaranteedUpdate(key string, ptrToType runtime.Object, igno
 		ttl := uint64(0)
 		if node != nil {
 			index = node.ModifiedIndex
-			if node.TTL > 0 {
+			if node.TTL != 0 {
 				ttl = uint64(node.TTL)
 			}
+			if node.Expiration != nil && ttl == 0 {
+				ttl = 1
+			}
 		} else if res != nil {
 			index = res.EtcdIndex
 		}
 
 		if newTTL != nil {
+			if ttl != 0 && *newTTL == 0 {
+				// TODO: remove this after we have verified this is no longer an issue
+				glog.V(4).Infof("GuaranteedUpdate is clearing TTL for %q, may not be intentional", key)
+			}
 			ttl = *newTTL
 		}