# ros2nix Tool to convert [ROS][] `package.xml` to [Nix][] expressions compatible with [nix-ros-overlay][]. Under the hood, it uses [rosdep][] to convert ROS package names to nixpkgs attributes so that you don't have to be concerned with it. [rosdep]: https://github.com/ros-infrastructure/rosdep ## Installation - With nix-env: ```sh nix-env --install -f https://github.com/wentasah/ros2nix/archive/main.tar.gz ``` or try it out without installation: ```sh nix-shell -p '(import (fetchTarball "https://github.com/wentasah/ros2nix/archive/main.tar.gz")).default' ``` - With Nix flakes experimental feature: ```sh nix profile install github:wentasah/ros2nix ``` or try it out without installation: ```sh nix shell github:wentasah/ros2nix ``` ## Usage examples ### Nixifying local ROS workspace 1. Create Nix expressions for local packages ```sh ros2nix $(find -name package.xml) ``` This also creates `./overlay.nix` and `./default.nix` for easy integration and/or testing of created packages. 2. Try building some of your packages (replace `my-package` with real name): ```sh nix-build -A rosPackages.humble.my-package nix-build -A rosPackages.jazzy.my-package ``` If the build succeeds, you're probably done. Failures can be caused by several things: - Missing dependencies in your `package.xml` - Missing/stale `nixos` keys for nixpkgs packages in [rosdep yaml database][] - Bugs in your packages (e.g. in `CMakeLists.txt`) - Bugs in `ros2nix` – please, report them - Bugs in `nix-ros-overlay` – report them too :-) [rosdep yaml database]: https://github.com/ros/rosdistro/tree/master/rosdep ## Nixifying 3rd party ROS packages You can use 3rd party ROS packages (which are not a part of ROS distribution) in your project as follows. We'll show the procedure on the [Autoware][] project as an example. 1. Clone the 3rd party repositories, e.g. ```sh git clone https://github.com/autowarefoundation/autoware.git cd autoware mkdir src vcs import src < autoware.repos cd .. ros2nix --output-as-nix-pkg-name --fetch $(find -name package.xml|grep -v ament_cmake) ``` This will create all Nix expressions in the current directory and named according to their package names. The expressions will _fetch_ the source code from GitHub instead of from local filesystem. Note that we ignore ament_cmake packages forked by autoware since they break the build. 2. Try building some packages: ``` nix-build -A rosPackages.humble.autoware-overlay-rviz-plugin ``` Note that not all autoware packages can be build successfully. > [!TIP] > > To build all generated packages, run `ros2nix` with the `--flake` > switch and then run `nix flake check` (depending on your > configuration, you may need to add `--experimental-features > 'nix-command flakes'`). [Autoware]: https://autoware.org/ ## ros2nix reference ``` usage: ros2nix [-h] [--output OUTPUT | --output-as-ros-pkg-name | --output-as-nix-pkg-name] [--output-dir OUTPUT_DIR] [--fetch] [--distro DISTRO] [--src-param SRC_PARAM] [--source-root SOURCE_ROOT] [--do-check] [--extra-build-inputs DEP1,DEP2,...] [--extra-propagated-build-inputs DEP1,DEP2,...] [--extra-check-inputs DEP1,DEP2,...] [--extra-native-build-inputs DEP1,DEP2,...] [--flake] [--nixfmt] [--compare] [--copyright-holder COPYRIGHT_HOLDER] [--license LICENSE] package.xml [package.xml ...] positional arguments: package.xml Path to package.xml options: -h, --help show this help message and exit --output OUTPUT Output filename (default: package.nix) --output-as-ros-pkg-name Name output files based on ROS package name, e.g., package_name.nix. Implies --output-dir=. (default: False) --output-as-nix-pkg-name Name output files based on Nix package name, e.g., package-name.nix. Implies --output-dir=. (default: False) --output-dir OUTPUT_DIR Directory to generate output files in. By default, package files are stored next to their corresponding package.xml, top-level files like overlay.nix in the current directory. (default: None) --fetch Use fetches like fetchFromGitHub in src attribute values. The fetch function and its parameters are determined from the local git work tree. sourceRoot attribute is set if needed and not overridden by --source-root. (default: False) --distro DISTRO ROS distro (used as a context for evaluation of conditions in package.xml, in the name of the Nix expression and in flake.nix). Note that the generated Nix expression can be used with any ROS distro if its package.xml contains no conditions. (default: rolling) --src-param SRC_PARAM Adds a parameter to the generated function and uses it as a value of the src attribute (default: None) --source-root SOURCE_ROOT Set sourceRoot attribute value in the generated Nix expression. Substring '{package_name}' gets replaced with the package name. (default: None) --do-check Set doCheck attribute to true (default: False) --extra-build-inputs DEP1,DEP2,... Additional dependencies to add to the generated Nix expressions (default: []) --extra-propagated-build-inputs DEP1,DEP2,... Additional dependencies to add to the generated Nix expressions (default: []) --extra-check-inputs DEP1,DEP2,... Additional dependencies to add to the generated Nix expressions (default: []) --extra-native-build-inputs DEP1,DEP2,... Additional dependencies to add to the generated Nix expressions (default: []) --flake Generate top-level flake.nix instead of default.nix. Use with --fetch if some package.xml files are outside of the flake repo (default: False) --nixfmt Format the resulting expressions with nixfmt (default: False) --compare Don't write any file, but check whether writing the file would change existing files. Exit with exit code 2 if a change is detected. Useful for CI. (default: False) --copyright-holder COPYRIGHT_HOLDER Copyright holder of the generated Nix expressions. (default: None) --license LICENSE License of the generated Nix expressions, e.g. 'BSD' (default: None) ``` [ROS]: https://www.ros.org/ [Nix]: https://nixos.org/ [nix-ros-overlay]: https://github.com/lopsided98/nix-ros-overlay