Merge pull request #1550 from deis/fix_builder_race

fix(builder): fix race condition in /bin/boot

Author: Gabriel Monroy

builder/bin/boot

@@ -60,14 +60,12 @@ docker load -i /progrium_cedarish.tar
 # pull required images
 
 # Custom slugbuilder?
-etcdctl --no-sync -C $ETCD mk /deis/slugbuilder/image deis/slugbuilder:latest >/dev/null 2>&1 || true
-SLUGBUILDER=`etcdctl --no-sync -C $ETCD get /deis/slugbuilder/image`
+SLUGBUILDER=`etcdctl --no-sync -C $ETCD get /deis/slugbuilder/image 2>/dev/null || etcdctl --no-sync -C $ETCD mk /deis/slugbuilder/image deis/slugbuilder:latest 2>/dev/null`
 docker pull ${SLUGBUILDER}
 docker tag  ${SLUGBUILDER} deis/slugbuilder:latest
 
 # Custom slugrunner?
-etcdctl --no-sync -C $ETCD mk /deis/slugrunner/image deis/slugrunner:latest >/dev/null 2>&1 || true
-SLUGRUNNER=`etcdctl --no-sync -C $ETCD get /deis/slugrunner/image`
+SLUGRUNNER=`etcdctl --no-sync -C $ETCD get /deis/slugrunner/image 2>/dev/null || etcdctl --no-sync -C $ETCD mk /deis/slugrunner/image deis/slugrunner:latest 2>/dev/null`
 docker pull ${SLUGRUNNER}
 docker tag  ${SLUGRUNNER} deis/slugrunner:latest