Description

Currently, ros2 pkg create only supports ament_cmake and ament_python build types. There is no way to generate a new package skeleton for Rust. This forces developers using rclrs or similar crates to manually create a Cargo crate, add a package.xml, and configure ament_cargo.

This workflow is inconsistent with the developer experience in C++/Python and adds unnecessary friction for those exploring/have to use Rust in the ROS 2 ecosystem.

Motivation

To lower the entry barrier of Rust for ROS2 ecosystem, add an additional build type ament_cargo to ros2 pkg create, which would generate a minimal Rust crate structure alongside the usual ROS 2 metadata.

Design / Implementation Considerations

Proposed Generated Structure:

my_rust_pkg/
├── Cargo.toml
├── package.xml
└── src/
    └── main.rs

Cargo.toml:

[package]
name = "my-rust-pkg"
version = "0.1.0"
edition = "2021"

[dependencies]
anyhow = "1.0"
rclrs = "0.5.1"


[workspace]

package.xml:

<package format="3">
  <name>my_rust_pkg</name>
  <version>0.0.0</version>
  <description>TODO: Package description</description>
  <maintainer email="[email protected]">user</maintainer>
  <license></license>
  <buildtool_depend>ament_cargo</buildtool_depend>
  <depend>rclrs</depend>
  <export>
    <build_type>ament_cargo</build_type>
  </export>
</package>

src/main.rs:

use anyhow::Result;
use rclrs::{Context, CreateBasicExecutor, RclrsErrorFilter, SpinOptions};
/// Creates a ROS 2 context and node, prints a hello message,
/// then spins until shutdown.
fn main() -> Result<()> {
    let context: Context = Context::default_from_env()?;
    let mut executor = context.create_basic_executor();
    let _node = executor.create_node("hello_rust_node")?;
    println!("Hello from rclrs 0.5.1!");
    executor.spin(SpinOptions::default()).first_error()?;
    Ok(())
}

Additional Information

This feature will

• Provide a consistent developer experience across C++, Python, and Rust.
• Lower the entry barrier for trying Rust in ROS 2.
• Encourage the adoption of Rust within the ecosystem by providing a first-class workflow.

The above proposal is off the top of my head. If I get a positive feedback on this,I would like to improve the idea and contribute a PR to add this functionality. Two questions:

• Is this within the intended scope of ros2 pkg create?
• Would you prefer this support to live in the core tool, or in a separate plugin (Which I believe does exist)?

If accepted, I am willing to prepare and maintain the PR.