You're reading the documentation for an older, but still supported, version of ROS 2. For information on the latest version, please have a look at Humble.

Launch

ROS 2 Launch files allow you to start up and configure a number of executables containing ROS 2 nodes simultaneously.

  1. Creating a launch file.

    Learn how to create a launch file that will start up nodes and their configurations all at once.

  2. Launching and monitoring multiple nodes.

    Get a more advanced overview of how launch files work.

  3. Using substitutions.

    Use substitutions to provide more flexibility when describing reusable launch files.

  4. Using event handlers.

    Use event handlers to monitor the state of processes or to define a complex set of rules that can be used to dynamically modify the launch file.

  5. Managing large projects.

    Structure launch files for large projects so they may be reused as much as possible in different situations. See usage examples of different launch tools like parameters, YAML files, remappings, namespaces, default arguments, and RViz configs.

Note

You can also use XML and YAML to create launch files. You can see a comparison of these different ROS 2 launch formats in Using Python, XML, and YAML for ROS 2 Launch Files.

Note

If you are coming from ROS 1, you can use the ROS Launch Migration guide to help you migrate your launch files to ROS 2.