From 3ef0a8615ad77f407f7b275644e42e07c597a38d Mon Sep 17 00:00:00 2001
From: Matt Boersma <mboersma@deis.com>
Date: Wed, 18 Jan 2017 15:03:06 -0700
Subject: [PATCH] feat(Makefile): set docker build flags via environment
 variable

---
 .travis.yml | 2 ++
 Makefile    | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index dc886dce..c32da4df 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,8 @@ cache:
     - $HOME/.cache/pip
 services:
   - docker
+env:
+  - DOCKER_BUILD_FLAGS="--pull --no-cache"
 install:
   - make deps
 script:
diff --git a/Makefile b/Makefile
index d90aa651..c0debaec 100644
--- a/Makefile
+++ b/Makefile
@@ -47,7 +47,7 @@ docker-test: docker-build-docs
 	${DEV_ENV_CMD} ${IMAGE} $(TEST_CMD)
 
 docker-build:
-	docker build --rm -t ${IMAGE} .
+	docker build ${DOCKER_BUILD_FLAGS} -t ${IMAGE} .
 
 docker-serve:
 	${DEV_ENV_CMD} ${IMAGE} $(MKDOCSSERVE)