ROS2 Virtual Environment Utility

A ROS2 package for managing isolated Python virtual environments for individual ROS2 packages.

Overview

The ros2_venv_utility provides tools to create and manage package-specific Python virtual environments that integrate with ROS2 launch files. This allows each ROS2 package to have its own isolated Python dependencies while still accessing system ROS2 packages.

Package Components

This utility consists of two ROS2 packages:

1. ros2_venv_scripts

Contains bash scripts for virtual environment management:

• setup_env.bash - Creates and populates virtual environments
• check_venv_compatibility.bash - Validates virtual environment compatibility
• post_install_venv.cmake - CMake integration for post-installation setup

2. ros2_venv_launch_util

Provides Python utilities for launch file integration:

• launch_util.py - Functions to integrate virtual environments with ROS2 launch files

Installation

Build Instructions

1. Clone this repository into your ROS2 workspace:

   cd ~/your_ros2_ws/src
   git clone [email protected]:tu-darmstadt-ros-pkg/ros2_venv_utility.git

2. Build the packages:

   cd ~/your_ros2_ws
   colcon build --packages-select ros2_venv_scripts ros2_venv_launch_util

3. Source your workspace:

   source install/setup.bash

Integration Guide

To create a new package with inbuilt venv support hector-ros2-pkg-create can be used by choosing the python-cmake template. To integrate virtual environment support with an existing ROS2 package:

Step 1: Convert to ament_cmake Package

Update your package.xml to use ament_cmake build type:

<buildtool_depend>ament_cmake</buildtool_depend>

<depend>ament_cmake</depend>
<depend>rclpy</depend>
<!-- your other dependencies -->
<depend>ros2_venv_scripts</depend>

<export>
  <build_type>ament_cmake</build_type>
</export>

Step 2: Create/ Change CMakeLists.txt

Create/ Change a CMakeLists.txt with virtual environment integration:

cmake_minimum_required(VERSION 3.8)
project(your_package_name)

# Find dependencies
find_package(ament_cmake REQUIRED)
find_package(ament_cmake_python REQUIRED)
find_package(ros2_venv_scripts REQUIRED)

# Install Python package
ament_python_install_package(${PROJECT_NAME})

# Install Python executables
install(PROGRAMS
  your_package_name/your_node.py
  DESTINATION lib/${PROJECT_NAME}
)

# Virtual environment setup with configurable skip option
set(SKIP_VENV
    OFF
    CACHE BOOL "Whether to skip the venv setup. Should be True for distribution builds.")

if(SKIP_VENV)
  message(STATUS "Skipping venv setup")
else()
  ament_index_get_resource(venv_util_scripts_path "ros2_venv_utility_scripts" "ros2_venv_scripts")
  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/requirements.txt" DESTINATION "venv")
  install(SCRIPT "${venv_util_scripts_path}/post_install_venv.cmake")
endif()

ament_package()

Step 3: Create Requirements File

Create a requirements.txt file in your package root.

Step 4: Update Launch Files

For launch packages, add ros2_venv_launch_util dependency and use the virtual environment:

package.xml (launch package):

<depend>ros2_venv_launch_util</depend>

Launch file:

from launch import LaunchDescription
from launch_ros.actions import Node
from ament_index_python.packages import get_package_share_directory
from ros2_venv_launch_util.launch_util import add_venv_to_current_env

def generate_launch_description():
    pkg_share = get_package_share_directory('your_package_name')
    env = add_venv_to_current_env(pkg_share)

    return LaunchDescription([
        Node(
            package='your_package_name',
            executable='your_node.py',
            name='your_node_name',
            env=env,  # Virtual environment is applied here
            # ... other parameters
        )
    ])

Authors

• Marek Daniv ([email protected])