Exercise 1: Your first ROS 2 workspace¶

# Solution to Exercise 1: Your first ROS 2 workspace.
#
# A complete ROS 2 environment with no ROS installed on the machine, and the
# same workspace targeting two ROS distributions at once:
#
#     pixi run sim              # turtlesim on Lyrical
#     pixi run teleop           # drive it with the arrow keys
#     pixi run -e kilted sim    # the same workspace, on Kilted
#     pixi run brain            # PyTorch on the CPU, or CUDA when available
#     pixi run --platform cuda-linux-64 cuda-check  # requires an NVIDIA GPU
#
# Colcon builds each distro into its own build/, install/ and log/ subdirectories.
# Run `pixi run -e <environment> build` once before launching nodes there.

[workspace]
name = "turtle-workspace"
description = "A ROS 2 workspace managed entirely by Pixi, targeting two distros"
channels = ["conda-forge"]
platforms = [
  { name = "cuda-linux-64", platform = "linux-64", cuda = "12" },
  "linux-64",
  "osx-arm64",
  "win-64",
  { name = "jetson", platform = "linux-aarch64", cuda = "13" },
]
version = "0.1.0"

# ---------------------------------------------------------------------------
# Shared by every environment: the toolchain and the tasks.
# ---------------------------------------------------------------------------
[dependencies]
# Colcon, CMake and compiler tooling for building our own package.
# Windows needs Visual Studio C++ Build Tools and a Windows SDK installed first;
# see docs/setup.md for Microsoft's installation instructions.
ros-dev-tools = ">=1.0"
pytorch = ">=2.5"
pytorch-gpu = { version = ">=2.5", when = "__cuda" }

[tasks.sim]
cmd = "ros2 run turtlesim turtlesim_node"
description = "Start the turtlesim window"

[tasks.teleop]
cmd = "ros2 run turtlesim turtle_teleop_key"
description = "Drive the turtle with the arrow keys"

[tasks.topics]
cmd = "ros2 topic list"
description = "List the ROS topics: proof that ROS works without sourcing anything"

[tasks.build]
cmd = "colcon --log-base log/$PIXI_ENVIRONMENT_NAME build --base-paths src --build-base build/$PIXI_ENVIRONMENT_NAME --install-base install/$PIXI_ENVIRONMENT_NAME"
description = "Build the packages into this ROS environment's own colcon overlay"

[tasks.test]
cmd = "python -c \"import os; print('ros:', os.environ['ROS_DISTRO'], 'ok')\""
description = "Prove ROS is active: what CI runs"

[tasks.test-overlay]
cmd = "python check_overlay.py"
description = "Check that ROS and both local packages belong to the selected environment"

# Run `pixi run build` once before the first launch so activation can find the overlay.
[tasks.brain]
cmd = "ros2 run turtle_brain brain"
depends-on = ["build"]
description = "Run the PyTorch ROS executable (build once before the first launch)"

[tasks.cuda-check]
cmd = "python src/turtle_brain/turtle_brain/check_cuda.py"
description = "Run a CUDA tensor computation; fail if CUDA is unavailable"

# Each environment activates only its own colcon overlay, without replaying the
# underlay chain recorded by setup.sh. Build once before launching either node.
[tasks.dance]
cmd = "ros2 run turtle_dancer dance"
depends-on = ["build"]
description = "Run our own node (the colcon overlay is sourced on activation)"


# ---------------------------------------------------------------------------
# ROS 2 Lyrical: the main workshop distro. The default
# environment, declared inline: its own channel and its own packages, on top
# of everything shared above. The rclcpp and geometry-msgs libraries the node
# uses come with ros-base.
# ---------------------------------------------------------------------------
[environments.default]
channels = ["https://prefix.dev/robostack-lyrical", "conda-forge"]

[environments.default.dependencies]
ros-lyrical-ros-base = ">=0.13"
ros-lyrical-turtlesim = ">=1.10"

[environments.default.target.unix.activation]
scripts = ["install/default/setup.sh"]

[environments.default.target.win-64.activation]
scripts = ["install/default/setup.bat"]

# ---------------------------------------------------------------------------
# ROS 2 Kilted: a different distribution, same workspace. A different channel
# and a different package prefix; the tasks come from the shared set above.
# ---------------------------------------------------------------------------
[environments.kilted]
channels = ["https://prefix.dev/robostack-kilted", "conda-forge"]

[environments.kilted.dependencies]
ros-kilted-ros-base = "*"
ros-kilted-turtlesim = "*"

[environments.kilted.target.unix.activation]
scripts = ["install/kilted/setup.sh"]

[environments.kilted.target.win-64.activation]
scripts = ["install/kilted/setup.bat"]