Create ROS Workspace

In this exercise, we will create and build an empty ROS workspace.

Motivation

Any ROS project begins with making a workspace. In this workspace, you will put all the things related to this particular project. In this module we will create the workspace where we will build the components of our Scan-N-Plan application.

Reference Example

Steps to creating a workspace: Creating a Workspace

Further Information and Resources

Additional details on what a ROS environment consists of and some basic checks you can run: Configuring a ROS2 Environment

Scan-N-Plan Application: Problem Statement

We have a good installation of ROS, and we need to take the first step to setting up our particular application. Your goal is to create a workspace for your application and its supplements.

Scan-N-Plan Application: Guidance

Create a Workspace

  1. Close any open terminal windows. Open a new terminal and source the “foxy” distribution.

    source /opt/ros/foxy/setup.bash
    
  2. Create the root workspace directory. Note that the required structure is a top-level directory and a src/ directory one level down. The directory name is a completely free choice. We will use ros2_ws throughout these tutorials.

    cd ~/
    mkdir --parents ros2_ws/src
    cd ros2_ws
    ls
    
  3. Build the workspace from the workspace root-directory (ros2_ws).

    colcon build
    ls
    
    • See that the ros2_ws directory now contains additional directories (build, install, log).
    • colcon build must always be run from the root of your workspace directory.
    • Don’t run colcon build from a terminal where you’ve also sourced this workspace’s setup file. Use a dedicated terminal for building.
  4. These new directories can be safely deleted at any time. This is sometimes used to resolve unusual build errors by “starting with a clean slate”. Note that colcon never changes any files in the src directory. Re-run colcon build to re-create the build/install/log directories.

    rm -r build/ install/ log/
    ls
    colcon build
    ls
    
  5. Make the contents of this workspace visible to ROS. Source the setup file in the install directory.

    source ~/ros2_ws/install/setup.bash
    
    • This file MUST be sourced for every new terminal.
    • This file will automatically include the ROS environment that was active when you first built this workspace. Make sure you have sourced the correct ROS distribution before building a new workspace for the first time!