Using Docker with ROSflight¶

If you aren't running a compatible version of Linux for ROS2, don't want to make changes to your system, want to be able to easily switch between ROS verions, or just want to containerize your applications, then you can use Docker containers.

Docker works by running self-contained systems called containers, which act kind of like a separate computer system but without all the overhead of a full virtual machine. Docker containers are based on Docker images, which provide the initial operating system, files, and programs for the Docker container. Fortunately, the developers of ROS provide Docker images for nearly all versions of ROS, which makes it very easy to get any version of ROS up and running on your system very quickly.

Docker Tutorials

This guide is not a Docker tutorial. There are a lot of great tutorials and resources for learning what Docker is and how to use it. For more information on Docker, see the Docker docs.

In this section, we will focus explicitly on how we use our Docker containers to set up a simulation environment, with some explanation of what we are doing.

Docker on Windows

If you are using Docker on Windows natively, be aware that GUI tools will not work. We have not tested GUI applications while using a Docker container in WSL. GUI applications in WSL work fine with a "native" installation of ROS2.

Using Docker instead of a native installation

If you choose to use Docker, you will need to be attached to your Docker container any time you run ROS2 commands in the following tutorials.

Note also that we have set up the container so that the build, install, log, and source files are mounted from the host system to the container, which enables you to have changes and builds that are persistent across Docker sessions.

Installing Docker¶

To get started, install Docker Engine, sometimes referred to as Docker server. You can install the desktop version (Docker Desktop), but just the engine works fine. Make sure you also have the docker compose utility installed.

You can check by running docker compose in a terminal.

Building¶

We have provided the Docker files that we use here.

Follow the steps 1-2 from the sim installation guide to set up the file structure. It should look like:

rosflight_ws/
    └── src/
        ├── roscopter/
        ├── rosflight_ros_pkgs/
        └── rosplane/

Navigate to the rosflight_ws directory:
```
cd /path/to/rosflight_ws
```
Build the Docker container:
```
docker compose -f src/rosflight_ros_pkgs/docker/compose.yaml build
```
Filepaths

Here we use the build and other docker compose commands from the rosflight_ws directory. You can run all these commands from the src/rosflight_ros_pkgs/docker directory (or any other directory), but make sure to update the relative paths appropriately.

Running the Docker container¶

To run the Docker container, we will first start the container in the background with:

docker compose -f src/rosflight_ros_pkgs/docker/compose.yaml up -d

Attach to the container with:

docker compose -f src/rosflight_ros_pkgs/docker/compose.yaml exec rosflight zsh

Tip

You can attach as many times as you want from different terminals!

Building the ROSflight workspace¶

Attach to the container using the above commands.

Build the rosflight_ws using the colcon build tool:

cd /path/to/rosflight_ws
colcon build

Resource Usage

Building the whole repository at once uses a lot of memory. If you get build errors, try running the build command with the following argument:

colcon build --executor sequential

Success

Your ROSflight workspace file structure should now look like

rosflight_ws/
  ├── build/
  ├── install/
  ├── log/
  └── src/
      ├── roscopter/
      ├── rosflight_ros_pkgs/
      └── rosplane/

Warning

During testing, we found some strange behavior with ROS when running a GUI enabled container on a system with ROS already installed. If you need a GUI enabled system, try to do so on a system without ROS installed (or at the very least avoid sourcing/using ROS on your system). Also avoid having multiple GUI enabled containers running at once.