Parameterize base image name for the nav2 build (issue space-ros#161)

navigation2/Dockerfile

@@ -16,10 +16,13 @@
 #
 # The script provides the following build arguments:
 #
-#   VCS_REF     - The git revision of the Space ROS source code (no default value).
-#   VERSION     - The version of Space ROS (default: "preview")
+#   VCS_REF         - The git revision of the Space ROS source code (no default value).
+#   VERSION         - The version of Space ROS (default: "preview")
+#   SPACE_ROS_IMAGE - The base Space ROS image to build on
 
-FROM osrf/space-ros:latest
+ARG SPACE_ROS_IMAGE=osrf/space-ros:latest
+
+FROM ${SPACE_ROS_IMAGE}
 
 # Define arguments used in the metadata definition
 ARG VCS_REF

navigation2/README.md

@@ -12,6 +12,14 @@ To build the docker image, run:
 
 The build process will take about 30 minutes, depending on the host computer.
 
+By default, this will build on top of the latest released version of the Space ROS base image (typically `osrf/space-ros:latest`).
+If building locally, the underlying base image can be set in the [build script](./build.sh), or through the environment with:
+
+```bash
+# Use a locally built image as the base
+SPACE_ROS_IMAGE="space-ros:main" ./build.sh
+```
+
 ## Running the Navigation2 Docker Image in a Container
 
 After building the image, you can see the newly-built image by running:

navigation2/build.sh

@@ -16,7 +16,9 @@ echo ""
 
 docker build -t $ORG/$IMAGE:$TAG \
     --build-arg VCS_REF="$VCS_REF" \
-    --build-arg VERSION="$VERSION" .
+    --build-arg VERSION="$VERSION" \
+    --build-arg SPACE_ROS_IMAGE="${SPACE_ROS_IMAGE:-osrf/space-ros:latest}" \
+    .
 
 echo ""
 echo "##### Done! #####"