adding DOCKER_PULL_IMGE environment variable, if set to 1 it will update the image before running

sabayon-buildpackages

@@ -3,6 +3,8 @@ set -e
 SAB_WORKSPACE="${SAB_WORKSPACE:-$PWD}"
 DOCKER_IMAGE="${DOCKER_IMAGE:-sabayon/builder-amd64}"
 SAB_ARCH="${SAB_ARCH:-intel}"
+DOCKER_PULL_IMAGE="${DOCKER_PULL_IMAGE:-0}"
+
 . /sbin/sabayondevkit-functions.sh
 
 if [ $# -eq 0 ]
@@ -33,6 +35,8 @@ docker_volumes=(-v "$SAB_WORKSPACE/local_overlay:/usr/local/portage"
 
 check_docker_requirements
 
+[ $DOCKER_PULL_IMAGE -eq 1 ] && docker pull $DOCKER_IMAGE
+
 [ -d "$SAB_WORKSPACE"/specs ] || mkdir "$SAB_WORKSPACE"/specs/
 [ -e "$SAB_WORKSPACE"/specs/custom.mask ] || touch "$SAB_WORKSPACE"/specs/custom.mask
 [ -e "$SAB_WORKSPACE"/specs/custom.unmask ] || touch "$SAB_WORKSPACE"/specs/custom.unmask