Merge pull request #13 from mboersma/build-no-cache

feat(Makefile): set docker build flags via environment variable

Author: mboersma

.travis.yml

@@ -5,6 +5,8 @@ branches:
 sudo: required
 services:
   - docker
+env:
+  - DOCKER_BUILD_FLAGS="--pull --no-cache"
 install:
   - make docker-build
 script:

Makefile

@@ -25,7 +25,7 @@ dev:
 # For cases where we're building from local
 # We also alter the RC file to set the image name.
 docker-build:
-	docker build --no-cache --rm -t ${IMAGE} rootfs
+	docker build ${DOCKER_BUILD_FLAGS} -t ${IMAGE} rootfs
 	docker tag ${IMAGE} ${MUTABLE_IMAGE}
 
 test: test-style test-unit test-functional