docker-ros2-development

# Docker-Based ROS2 Development Skill

## When to Use This Skill

- Writing Dockerfiles for ROS2 workspaces with colcon builds
- Setting up docker-compose for multi-container robotic systems
- Debugging DDS discovery failures between containers (CycloneDDS, FastDDS)
- Configuring GPU passthrough with NVIDIA Container Toolkit for perception nodes
- Forwarding X11 or Wayland displays for rviz2 and rqt tools
- Managing USB device passthrough for cameras, LiDARs, and serial devices
- Building CI/CD pipelines with Docker-based ROS2 builds and test runners
- Creating devcontainer configurations for VS Code with ROS2 extensions
- Optimizing Docker layer caching for colcon workspace builds
- Designing dev-vs-deploy container strategies with multi-stage builds

## ROS2 Docker Image Hierarchy

Official OSRF images follow a layered hierarchy. Always choose the smallest base that satisfies dependencies.

```
┌──────────────────────────────────────────────────────────────────┐
│  ros:<distro>-desktop-full  (~3.5 GB)                            │
│  ┌────────────────────────────────────────────────────────────┐  │
│  │  ros:<distro>-desktop     (~2.8 GB)                        │  │
│  │  ┌──────────────────────────────────────────────────────┐  │  │
│  │  │  ros:<distro>-perception (~2.2 GB)                    │  │  │
│  │  │  ┌────────────────────────────────────────────────┐   │  │  │
│  │  │  │  ros:<distro>-ros-base  (~1.1 GB)              │   │  │  │
│  │  │  │  ┌──────────────────────────────────────────┐  │   │  │  │
│  │  │  │  │  ros:<distro>-ros-core (~700 MB)         │  │   │  │  │
│  │  │  │  └──────────────────────────────────────────┘  │   │  │  │
│  │  │  └────────────────────────────────────────────────┘   │  │  │
│  │  └──────────────────────────────────────────────────────┘  │  │
│  └────────────────────────────────────────────────────────────┘  │
└──────────────────────────────────────────────────────────────────┘
```

| Image Tag               | Base OS        | Size    | Contents                                    | Use Case                            |
|--------------------------|----------------|---------|---------------------------------------------|-------------------------------------|
| `ros:humble-ros-core`    | Ubuntu 22.04   | ~700 MB | rclcpp, rclpy, rosout, launch               | Minimal runtime for single nodes    |
| `ros:humble-ros-base`    | Ubuntu 22.04   | ~1.1 GB | ros-core + common_interfaces, rosbag2       | Most production deployments         |
| `ros:humble-perception`  | Ubuntu 22.04   | ~2.2 GB | ros-base + image_transport, cv_bridge, PCL  | Camera/lidar perception pipelines   |
| `ros:humble-desktop`     | Ubuntu 22.04   | ~2.8 GB | perception + rviz2, rqt, demos              | Development with GUI tools          |
| `ros:jazzy-ros-core`     | Ubuntu 24.04   | ~750 MB | rclcpp, rclpy, rosout, launch               | Minimal runtime (Jazzy/Noble)       |
| `ros:jazzy-ros-base`     | Ubuntu 24.04   | ~1.2 GB | ros-core + common_interfaces, rosbag2       | Production deployments (Jazzy)      |

## Multi-Stage Dockerfiles for ROS2

### Dev Stage

The development stage includes build tools, debuggers, and editor support for interactive use.

```dockerfile
FROM ros:humble-desktop AS dev
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential cmake gdb python3-pip \
    python3-colcon-common-extensions python3-rosdep \
    ros-humble-ament-lint-auto ros-humble-ament-cmake-pytest \
    ccache \
    && rm -rf /var/lib/apt/lists/*
ENV CCACHE_DIR=/ccache
ENV CC="ccache gcc"
ENV CXX="ccache g++"
```

### Build Stage

Copies only `src/` and `package.xml` files to maximize cache hits during dependency resolution.

```dockerfile
FROM ros:humble-ros-base AS build
RUN apt-get update && apt-get install -y --no-install-recommends \
    python3-colcon-common-extensions python3-rosdep \
    && rm -rf /var/lib/apt/lists/*
WORKDIR /ros2_ws
# Copy package manifests first for dependency caching
COPY src/my_pkg/package.xml src/my_pkg/package.xml
RUN . /opt/ros/humble/setup.sh && apt-get update && \
    rosdep install --from-paths src --ignore-src -r -y && \
    rm -rf /var/lib/apt/lists/*
# Source changes invalidate only this layer and below
COPY src/ src/
RUN . /opt/ros/humble/setup.sh && \
    colcon build --cmake-args -DCMAKE_BUILD_TYPE=Release \
      --event-handlers console_direct+
```

### Runtime Stage

Contains only the built install space and runtime dependencies. No compilers, no source code.

```dockerfile
FROM ros:humble-ros-core AS runtime
RUN apt-get update && apt-get install -y --no-install-recommends \
    python3-yaml ros-humble-rmw-cyclonedds-cpp \
    && rm -rf /var/lib/apt/lists/*
COPY --from=build /ros2_ws/install /ros2_ws/install
RUN groupadd -r rosuser && useradd -r -g rosuser -m rosuser
USER rosuser
COPY ros_entrypoint.sh /ros_entrypoint.sh
ENTRYPOINT ["/ros_entrypoint.sh"]
CMD ["ros2", "launch", "my_pkg", "bringup.launch.py"]
```

### Full Multi-Stage Dockerfile

```dockerfile
# syntax=docker/dockerfile:1
# Usage:
#   docker build --target dev -t my_robot:dev .
#   docker build --target runtime -t my_robot:latest .
ARG ROS_DISTRO=humble
ARG BASE_IMAGE=ros:${ROS_DISTRO}-ros-base

# Stage 1: Dependency base — install apt and rosdep deps
FROM ${BASE_IMAGE} AS deps
RUN apt-get update && apt-get install -y --no-install-recommends \
    python3-colcon-common-extensions python3-rosdep \
    && rm -rf /var/lib/apt/lists/*
WORKDIR /ros2_ws
# Copy only package.xml files for rosdep resolution (maximizes cache reuse)
COPY src/my_robot_bringup/package.xml src/my_robot_bringup/package.xml
COPY src/my_robot_perception/package.xml src/my_robot_perception/package.xml
COPY src/my_robot_msgs/package.xml src/my_robot_msgs/package.xml
COPY src/my_robot_navigation/package.xml src/my_robot_navigation/package.xml
RUN . /opt/ros/${ROS_DISTRO}/setup.sh && \
    apt-get update && \
    rosdep install --from-paths src --ignore-src -r -y && \
    rm -rf /