Adding docker cache to UI containers

Change-Id: Ie5a8a69f4e037ec110a57ea938335e0c4e47f8a7
diff --git a/common/Makedefs b/common/Makedefs
index 72a4654..eb72299 100644
--- a/common/Makedefs
+++ b/common/Makedefs
@@ -1,6 +1,8 @@
 # common/Makedefs
 # Defines commonly used Makefile variables
 
+NO_DOCKER_CACHE      ?= false
+
 COMMON_DIR           ?= $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
 CONFIG_DIR           ?= $(COMMON_DIR)
 
diff --git a/common/Makefile b/common/Makefile
index c8b6b76..ce0b916 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -184,11 +184,11 @@
 
 xos_rest_gw_c:
 	# this folder is cloned by repo
-	cd $(LIBRARY_DIR)/xos-rest-gw; sudo docker build -t xosproject/xos-rest-gw .
+	cd $(LIBRARY_DIR)/xos-rest-gw; sudo docker build --no-cache=${NO_DOCKER_CACHE} -t xosproject/xos-rest-gw .
 
 xos_gui_c:
 	# this folder is cloned by repo
-	cd $(LIBRARY_DIR)/xos-gui; sudo docker build -t xosproject/xos-gui .
+	cd $(LIBRARY_DIR)/xos-gui; sudo docker build --no-cache=${NO_DOCKER_CACHE} -t xosproject/xos-gui .
 
 
 # utilties/convenience targets