Docker Setup

Docker provides an isolated, pre-configured environment for running the SCARA ROS2 EtherCAT Workshop without modifying your host system.

Prerequisites

Requirements

• Docker installed on your system
• At least 8 GB of disk space
• (Optional) rocker for GUI support

Quick Start

Basic Docker Setup

1. Clone the repository (if you haven't already):

git clone https://github.com/ICube-Robotics/ecat_ros2_workshop.git
cd ecat_ros2_workshop

1. Build the Docker image:

docker build --tag ecat_ros2_workshop:jazzy --file .docker/Dockerfile .

Build Time

The first build may take 10-20 minutes depending on your internet connection and system performance.

1. Run the container:

docker run ecat_ros2_workshop:jazzy ros2 launch scara_bringup scara.launch.py

Running with GUI

Option 1: Using Rocker (Recommended)

Rocker provides seamless X11 forwarding and device access.

1. Install rocker:

sudo apt update
sudo apt install python3-rocker

1. Run with GUI support:

rocker --net=host --x11 --devices /dev/dri --user ecat_ros2_workshop:jazzy ros2 launch scara_bringup scara.launch.py

Rocker Options

• --net=host: Uses host networking for ROS2 communication
• --x11: Enables X11 forwarding for GUI applications
• --devices /dev/dri: Mounts Direct Rendering Infrastructure for hardware-accelerated graphics (Intel GPUs)
• --user: Runs as non-root user for better security

Option 2: Using noVNC (Web-Based)

noVNC provides a web-based VNC client accessible through your browser - no X11 configuration needed!

1. Build the noVNC image:

# First ensure the base image is built
docker build --tag ecat_ros2_workshop:jazzy --file .docker/Dockerfile .

# Build the noVNC image
docker build --tag ecat_ros2_workshop:jazzy_novnc --file .docker/Dockerfile_novnc .

1. Run the noVNC container:

docker run --rm -p 6080:6080 -it ecat_ros2_workshop:jazzy_novnc

1. Access the desktop:

Open your web browser and navigate to:

http://localhost:6080/vnc.html

1. Inside the noVNC session, open a terminal and run:

cd ros2_dev/ecat_ros2_workshop/
source install/setup.bash
ros2 launch scara_bringup scara.launch.py

Browser Compatibility

noVNC works best with modern browsers (Chrome, Firefox, Edge). For optimal performance, use a desktop browser rather than mobile.

Interactive Shell

To explore and interact with the environment:

docker run -it ecat_ros2_workshop:jazzy

Inside the container:

cd ros2_dev/ecat_ros2_workshop/
source install/setup.bash

# Now you can run any ROS2 commands
ros2 launch scara_bringup scara.launch.py
ros2 topic list
ros2 control list_controllers

Development Workflow

Mounting Local Code

To develop code on your host and run it in the container:

docker run -it \
  -v $(pwd):/workspace \
  -w /workspace \
  ecat_ros2_workshop:jazzy \
  bash

Inside the container:

# Rebuild after changes
colcon build
source install/setup.bash
ros2 launch scara_bringup scara.launch.py

Persistent Container

Create a named container to preserve your changes:

# Create and start the container
docker run -it --name scara_dev ecat_ros2_workshop:jazzy bash

# Later, restart and attach to the same container
docker start scara_dev
docker attach scara_dev

Hardware Acceleration

NVIDIA GPU Support

For NVIDIA GPU support, use the NVIDIA Container Toolkit:

# Install NVIDIA Container Toolkit
distribution=$(. /etc/os-release;echo $ID$VERSION_ID)
curl -s -L https://nvidia.github.io/nvidia-docker/gpgkey | sudo apt-key add -
curl -s -L https://nvidia.github.io/nvidia-docker/$distribution/nvidia-docker.list | \
  sudo tee /etc/apt/sources.list.d/nvidia-docker.list

sudo apt update
sudo apt install -y nvidia-container-toolkit
sudo systemctl restart docker

# Run with GPU support
docker run --gpus all -it ecat_ros2_workshop:jazzy

Intel Integrated Graphics

For Intel integrated graphics (already included in rocker command):

rocker --devices /dev/dri ecat_ros2_workshop:jazzy

Docker Compose (Advanced)

For more complex setups, create a docker-compose.yml:

version: '3.8'

services:
  scara_workshop:
    image: ecat_ros2_workshop:jazzy
    container_name: scara_workshop
    stdin_open: true
    tty: true
    network_mode: host
    environment:
      - DISPLAY=${DISPLAY}
      - QT_X11_NO_MITSHM=1
    volumes:
      - /tmp/.X11-unix:/tmp/.X11-unix:rw
      - ./:/workspace
    devices:
      - /dev/dri:/dev/dri
    command: bash

Run with:

xhost +local:docker
docker-compose up

Troubleshooting

Display Issues

If you encounter display errors with rocker:

# Allow Docker to connect to X server
xhost +local:docker

# Run rocker again
rocker --x11 ecat_ros2_workshop:jazzy

Network Issues

If ROS2 nodes can't communicate:

# Use host networking
docker run --net=host -it ecat_ros2_workshop:jazzy

Permission Denied

If you get permission errors:

# Add your user to docker group
sudo usermod -aG docker $USER

# Log out and back in for changes to take effect

Container Size

To check Docker disk usage:

docker system df

# Clean up unused containers and images
docker system prune -a

Comparison: Docker Methods

Method	Pros	Cons	Best For
Basic	Simple, fast	No GUI	Headless testing
Rocker	Native performance, hardware acceleration	Requires X11 setup	Local development
noVNC	Works anywhere, no X11 needed	Slight latency	Remote access, web-based

Docker Images Availability

Prebuilt Docker images for this workshop are available on Docker Hub with the prefix mc3ed/. For example:

docker pull mc3ed/ecat_ros2_workshop:jazzy

Replace jazzy with the desired tag as needed. Use the mc3ed/ prefix for all images referenced in this documentation.

Next Steps

Now that you have Docker set up:

• Continue with the ros2_control Overview
• Try running the tutorials inside Docker
• Explore the URDF Tutorial

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Tip: Docker is great for trying things out, but for serious development, consider a native installation for better performance.