diff --git a/build/docker/vars.sh b/build/docker/vars.sh
new file mode 100755
index 0000000..752e282
--- /dev/null
+++ b/build/docker/vars.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+[[ ! -z "$DOCKER_USER" ]] || export DOCKER_USER=$DEFAULT_DOCKER_USER
+[[ ! -z "$DOCKER_REPO" ]] || export DOCKER_REPO=$DEFAULT_DOCKER_REPO
+[[ ! -z "$DOCKER_TAG" ]]  || export DOCKER_TAG=$DOCKER_USER/$DOCKER_REPO:$DISTRO