This document provides instructions on how to easily set up and use Zenoh DDS as the underlying middleware.

What Is Zenoh DDS?

Zenoh is a pub/sub/query protocol that unifies data in motion, data at rest and computations. That said, one way of thinking about Zenoh is to imagine it as a data liberator protocol. Zenoh liberates data in several dimensions.

Why Set This Up?

In the context of Robot Middleware Framework (RMF), it has been strongly hinted by maintainers that the Zenoh DDS will be de-facto DDS used for RMF-enabled components going forward.

For general ROS 2 development best practices, Zenoh offers a rust-based and memory-safe approach for communications between ROS 2-based applications going forward.

Dependencies

  • ROS 2 Jazzy

Note that Zenoh is only official supported for ROS 2 Jazzy.

Instructions

To get your ROS 2 components running with Zenoh, there are 2 critical steps to do as follows:

  • Start a Zenoh server.
  • Ensure your custom ROS package is communicating with RMW_IMPLEMENTATION set to rmw_zenoh_cpp.

These instructions assumes that you are running on a Linux operating system such as Ubuntu:

1. Install rmw_zenoh_cpp:

sudo apt-get update && sudo apt-get install ros-jazzy-rmw-zenoh-cpp

2. Start the Zenoh server:

source /opt/ros/jazzy/setup.bash && ros2 run rmw_zenoh_cpp rmw_zenohd

3. Switch the default DDS to rmw_zenoh_cpp:

export RMW_IMPLEMENTATION=rmw_zenoh_cpp

3. Run your ROS 2 package.

Here is a quick and easy way of starting up a ROS 2 Jazzy-based Zenoh Server:



docker run -it --rm \
	--name zenoh_server_c \
	-e RMW_IMPLEMENTATION=rmw_zenoh_cpp \
	--network host \
cardboardcode/zenoh_server:jazzy bash -c "source /ros_entrypoint.sh && ros2 run rmw_zenoh_cpp rmw_zenohd"

References