ROS2 Rust Nodes - Custom ROS 2 Workspace with Rust

🚀 This repository is a ROS 2 workspace (ros2_ws) that contains a set of ROS 2 nodes written in Rust that demonstrate publisher/subscriber communication using the ros2_rust client library.

1. Prerequisites

• ROS 2 (ex Humble Hawksbill): Follow the ROS 2 Installation guide for Ubuntu.
• Rust Toolchain: Install Rust.
• colcon (for building the workspace)

2. Setting Up Your Environment

Step 1: Install and Build ros2_rust

Follow the instructions in ros2-rust/ros2_rust to install Rust bindings for ROS 2. Once cloned and set up, build it inside your workspace (e.g., ~/workspace):

cd ~/workspace
colcon build
source install/setup.bash

Step 2: Build This Workspace

This repository is already structured as a ROS 2 workspace. After cloning it, ensure it sources the ros2_rust build:

cd ~/ros2_ws
source /opt/ros/humble/setup.bash # Source the previously installed ros2 humble setup files
source ~/workspace/install/setup.bash  # Source ros2_rust
colcon build
source install/local_setup.bash

Note: The source install/local_setup.bash ensures both ros2_rust and this package are properly linked.

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3. Running the Rust Nodes

The nodes now use ROS 2 parameters instead of command-line arguments. Parameters can be set using --ros-args --param when running the nodes.

Publisher Node Parameters

topic: <string>             # Name of the ROS2 topic to publish to  
publish_rate_ms: <integer>  # Publication rate in milliseconds  
prefix: <string>            # Text appearing before the counter  
suffix: <string>            # Text appearing after the counter  
count_start: <integer>      # Initial counter value  

Subscriber Node Parameters

topic: <string>        # Name of the ROS2 topic to subscribe to  
output_file: <string>  # Path to the file where received messages will be logged  

Manual Run

You can run the nodes manually using the ros2 run command. For example:

Publisher:

ros2 run rust_nodes simple_publisher --ros-args \
  --param topic:=my_topic \
  --param publish_rate_ms:=1000 \
  --param prefix:="Hello" \
  --param suffix:="World" \
  --param count_start:=0
# Publishes: "Hello 0 World", "Hello 1 World", etc. every 1 second

Subscriber:

ros2 run rust_nodes simple_subscriber --ros-args \
  --param topic:=my_topic \
  --param output_file:=subscriber_output.txt

Launch Files

For convenience, multi-level Python launch files are provided in rust_nodes_bringup:

ros2 launch rust_nodes_bringup main_launch.py publish_rate_ms:=5000 prefix:=Hi suffix:=There count_start:=10

4. Important Notes

⚠ Configuring .cargo/config.toml This repository includes a .cargo/config.toml file, which must be modified for different environments:

• It contains local file paths that reference built dependencies in ros2_rust.

• Update the paths in .cargo/config.toml to match your setup after building ros2_rust.

• If the paths are incorrect, the build may fail due to missing dependencies.

Example: If ros2_rust was built in /home/user/my_ros2_rust_workspace, update:

[patch.crates-io.rclrs]
path = "/home/user/my_ros2_rust_workspace/install/rclrs/share/rclrs/rust"