rmw_zenoh_rs

An experimental implementation of the ROS 2 RMW (ROS Middleware) layer based on Zenoh.

This project was created as part of a learning exercise for Rust. The implementation is heavily inspired by rmw_zenoh.
Currently, it only works with ROS 2 Humble. Excluding the unimplemented Events and Content Filtering, this implementation has passed most of RMW tests.

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Requirements

• ROS 2 Humble

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Setup

1. Run a Docker container

docker run -it --net=host --name rmw_zenoh_rs_test osrf/ros:humble-desktop bash

2. Build rmw_zenoh_rs

# Update ROS dependencies
rosdep update
apt update

# Set up the workspace
mkdir -p ~/ws_rmw_zenoh_rs/src && cd ~/ws_rmw_zenoh_rs/src
git clone https://github.com/quadjr/rmw_zenoh_rs.git

# Install dependencies
cd ~/ws_rmw_zenoh_rs
rosdep install --from-paths src --ignore-src --rosdistro humble -y

# Build the project
source /opt/ros/humble/setup.bash
colcon build --cmake-args -DCMAKE_BUILD_TYPE=Release

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Test

1. Source the built workspace

Before running any commands, make sure the workspace is sourced:

cd ~/ws_rmw_zenoh_rs
source install/setup.bash

2. Terminate existing ROS 2 daemons

Stop any ROS 2 daemon processes started with a different RMW:

pkill -9 -f ros && ros2 daemon stop

This step is necessary because ROS 2 CLI commands (e.g., ros2 node list) may not function correctly if the daemon was started with a different RMW.

3. Run the talker node

In the first terminal:

docker exec -it rmw_zenoh_rs_test bash
cd ~/ws_rmw_zenoh_rs
source install/setup.bash
export RMW_IMPLEMENTATION=rmw_zenoh_rs
ros2 run demo_nodes_cpp talker

4. Run the listener node

In a second terminal:

docker exec -it rmw_zenoh_rs_test bash
cd ~/ws_rmw_zenoh_rs
source install/setup.bash
export RMW_IMPLEMENTATION=rmw_zenoh_rs
ros2 run demo_nodes_cpp listener

The listener node should start receiving messages on the /chatter topic.

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Configuration

Zenoh Configuration

The default Zenoh configuration file is located at config/DEFAULT_RMW_ZENOH_SESSION_CONFIG.json5.

To use a custom configuration file, set the ZENOH_SESSION_CONFIG_URI environment variable. For example:

export ZENOH_SESSION_CONFIG_URI=$HOME/MY_ZENOH_SESSION_CONFIG.json5

scouting.multicast.interface is overwritten with the loopback interface when the environment variable ROS_LOCALHOST_ONLY is set to 1.

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Logging

Logging functionality has not been implemented yet.

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Known Issues

• Events: Events has not been implemented yet.
• Content filtering: Content filtering has not been implemented yet.