feat(slam): add cartographer_ros

cartographer_ros/scripts/save_docker_cache.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# Copyright 2016 The Cartographer Authors
+#
+# Licensed 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.
+
+# Cache intermediate Docker layers. For a description of how this works, see:
+# https://giorgos.sealabs.net/docker-cache-on-travis-and-docker-112.html
+
+set -o errexit
+set -o verbose
+set -o pipefail
+
+if [[ ${TRAVIS_BRANCH} == "master" ]] &&
+    [[ ${TRAVIS_PULL_REQUEST} == "false" ]]; then
+  mkdir -p $(dirname ${DOCKER_CACHE_FILE})
+  IMAGE_NAMES=$(docker history -q cartographer_ros:${ROS_RELEASE} | grep -v '<missing>')
+  docker save ${IMAGE_NAMES} | gzip > ${DOCKER_CACHE_FILE}.new
+  mv ${DOCKER_CACHE_FILE}.new ${DOCKER_CACHE_FILE}
+fi