WIP: smaller docker image

hooks/build

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# File needs to be called /hooks/build relative to the Dockerfile.
+# Some environment variables are injected into the build hook, see: https://docs.docker.com/docker-hub/builds/advanced/.
+
+GIT_SHORT_HASH=$(echo $SOURCE_COMMIT | cut -c1-7)
+echo "Build hook running for git hash $GIT_SHORT_HASH"
+docker build --build-arg BUILD_IDENTIFIER=$DOCKER_TAG \
+             --build-arg BUILD_VERSION=$GIT_SHORT_HASH \
+             -t $IMAGE_NAME .