ROS 2 Domain Scanner

A fast, multi-threaded Python script to scan for active ROS 2 nodes across different domain IDs. It helps you quickly discover which domains are currently in use on your network and what nodes are running on them.

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Features

• Multi-threaded Scanning: Uses a ThreadPoolExecutor to scan multiple domain IDs concurrently, making the process significantly faster.
• Progress Bar: Provides a real-time progress bar to visualize the scan's status.
• Clear Output: Lists all active domain IDs and the nodes found within each one.
• Configurable Range: Easily change the range of domain IDs to scan by modifying the TOTAL_DOMAINS variable.
• Zero Dependencies: Requires only a standard Python 3 installation and a sourced ROS 2 environment.

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Prerequisites

• Python 3.x
• ROS 2 (e.g., Foxy, Humble, Iron) installed and sourced in your terminal.

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Usage

1. Clone the repository or download the script:

   git clone https://github.com/rigbetellabs/domain_id_scanner.git
   cd domain_id_scanner

   or simply save the ros2_domain_scanner.py file to your machine.

2. Make the script executable (optional but recommended):

   chmod +x ros2_domain_scanner.py

3. Run the scanner: Make sure you have sourced your ROS 2 environment first!

   source /opt/ros/humble/setup.bash
   python3 ros2_domain_scanner.py

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Example Output

The script will first display a progress bar while it scans the domains.

Scanning: [****************************************] 100%

Once complete, it will print a summary of all active domains and their nodes.

Scan complete.
Active domain IDs and nodes:

Domain ID 0:
   - /ros2_domain_scanner_node_1
   - /turtlesim

Domain ID 30:
   - /robot_state_publisher
   - /joint_state_publisher
   - /rviz2

If no nodes are found on any domain, it will report:

No active nodes found in any domain.

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How It Works

The script iterates through ROS 2 domain IDs from 0 to 232 (as defined by the TOTAL_DOMAINS constant). For each domain ID, it performs the following steps in a separate thread:

1. Sets the ROS_DOMAIN_ID environment variable for a subprocess.
2. Executes the ros2 node list command within that environment.
3. Captures the standard output of the command. If the output is not empty, it means active nodes were found.
4. A TimeoutExpired exception handles cases where a domain is unresponsive, preventing the script from hanging.
5. All discovered domains and their nodes are collected and displayed at the end of the scan. domain_id_scanner