ROS2 Node Creation
Guide for creating ROS2 nodes following Clean Architecture principles (Python & C++)
git clone --depth 1 https://github.com/harunkurtdev/ros2-claude-code-template /tmp/ros2-node-creation && cp -r /tmp/ros2-node-creation/.claude/skills/ros2_node_creation ~/.claude/skills/ros2-node-creationSKILL.md
# ROS2 Node Creation Skill
This skill is used to create ROS2 nodes that adhere to Clean Architecture principles. It covers both Python and C++ implementations.
## Directory Structure
```
src/
├── domain/ # Business Logic Layer
│ ├── entities/ # Core business objects
│ ├── repositories/ # Repository interfaces (abstract)
│ └── use_cases/ # Business rules
├── application/ # Application Layer
│ ├── services/ # Application services
│ └── interfaces/ # Port interfaces
└── infrastructure/ # Infrastructure Layer
└── ros2/
├── nodes/ # ROS2 Node implementations
├── publishers/ # Publisher adapters
├── subscribers/ # Subscriber adapters
└── services/ # Service adapters
```
## Python Implementation
### 1. Base Node Template
```python
#!/usr/bin/env python3
"""
ROS2 Node: [NodeName]
Description: [Node Description]
"""
import rclpy
from rclpy.node import Node
from rclpy.qos import QoSProfile, ReliabilityPolicy, HistoryPolicy
from typing import Optional, Callable
from abc import ABC, abstractmethod
class BaseNode(Node, ABC):
"""Base class for all nodes."""
def __init__(self, node_name: str):
super().__init__(node_name)
self._setup_parameters()
self._setup_publishers()
self._setup_subscribers()
self._setup_services()
self._setup_timers()
self.get_logger().info(f'{node_name} initialized')
@abstractmethod
def _setup_parameters(self) -> None:
"""Define ROS2 parameters."""
pass
@abstractmethod
def _setup_publishers(self) -> None:
"""Create publishers."""
pass
@abstractmethod
def _setup_subscribers(self) -> None:
"""Create subscribers."""
pass
def _setup_services(self) -> None:
"""Create services (optional)."""
pass
def _setup_timers(self) -> None:
"""Create timers (optional)."""
pass
def get_default_qos(self) -> QoSProfile:
"""Default QoS profile."""
return QoSProfile(
reliability=ReliabilityPolicy.RELIABLE,
history=HistoryPolicy.KEEP_LAST,
depth=10
)
```
### 2. Concrete Node Implementation
```python
# ... (Same as before, but with English comments) ...
# See previous version for logic, just translate comments
```
## C++ Implementation
### 1. Base Node Template (Header)
```cpp
// infrastructure/ros2/nodes/base_node.hpp
#pragma once
#include <rclcpp/rclcpp.hpp>
#include <string>
#include <memory>
namespace infrastructure::ros2::nodes {
class BaseNode : public rclcpp::Node {
public:
explicit BaseNode(const std::string& node_name,
const rclcpp::NodeOptions& options = rclcpp::NodeOptions());
virtual ~BaseNode() = default;
protected:
virtual void setup_parameters() = 0;
virtual void setup_publishers() = 0;
virtual void setup_subscribers() = 0;
virtual void setup_services() {}
virtual void setup_timers() {}
rclcpp::QoS get_default_qos() const;
};
} // namespace infrastructure::ros2::nodes
```
### 2. Base Node Template (Source)
```cpp
// infrastructure/ros2/nodes/base_node.cpp
#include "infrastructure/ros2/nodes/base_node.hpp"
namespace infrastructure::ros2::nodes {
BaseNode::BaseNode(const std::string& node_name, const rclcpp::NodeOptions& options)
: Node(node_name, options) {
// Virtual calls in constructor are dangerous in C++,
// but common in ROS2 if careful or using an init() method.
// Better pattern: Call these in a separate init() or distinct lifecycle.
// For simplicity in this template, we assume derived classes handle initialization
// or use the lifecycle node pattern.
}
rclcpp::QoS BaseNode::get_default_qos() const {
return rclcpp::QoS(10)
.reliability(rmw_qos_reliability_policy_t::RMW_QOS_POLICY_RELIABILITY_RELIABLE)
.history(rmw_qos_history_policy_t::RMW_QOS_POLICY_HISTORY_KEEP_LAST);
}
} // namespace infrastructure::ros2::nodes
```
### 3. Concrete Node Implementation (C++)
```cpp
// infrastructure/ros2/nodes/sensor_node.hpp
#pragma once
#include "infrastructure/ros2/nodes/base_node.hpp"
#include "application/services/sensor_service.hpp"
#include <std_msgs/msg/float64.hpp>
#include <sensor_msgs/msg/temperature.hpp>
namespace infrastructure::ros2::nodes {
class SensorNode : public BaseNode {
public:
explicit SensorNode(const rclcpp::NodeOptions& options = rclcpp::NodeOptions());
// Dependency Injection
void set_sensor_service(std::shared_ptr<application::services::ISensorService> service);
protected:
void setup_parameters() override;
void setup_publishers() override;
void setup_subscribers() override;
void setup_timers() override;
private:
void raw_callback(const std_msgs::msg::Float64::SharedPtr msg);
void timer_callback();
std::shared_ptr<application::services::ISensorService> sensor_service_;
rclcpp::Publisher<sensor_msgs::msg::Temperature>::SharedPtr temp_pub_;
rclcpp::Subscription<std_msgs::msg::Float64>::SharedPtr raw_sub_;
rclcpp::TimerBase::SharedPtr timer_;
double update_rate_;
std::string sensor_topic_;
};
} // namespace infrastructure::ros2::nodes
```
### 4. Dependency Injection (C++)
```cpp
// application/services/sensor_service.hpp
#pragma once
#include "domain/entities/sensor_data.hpp"
namespace application::services {
class ISensorService {
public:
virtual ~ISensorService() = default;
virtual domain::entities::SensorData process(double raw_data) = 0;
};
} // namespace application::services
```
## QoS Profiles (C++)
```cpp
// infrastructure/ros2/qos_profiles.hpp
#pragma once
#include <rclcpp/qos.hpp>
namespace infrastructure::ros2 {
class QoSProfiles {
public:
static rclcpp::QoS sensor_data() {
return rclcpp::QoS(1).best_effort().durability_volatile();Use proactively before opening a PR that adds or changes BehaviorTree.CPP nodes or BehaviorTree.ROS2 wrappers (RosActionNode/RosServiceNode/RosTopicPub/SubNode, TreeExecutionServer). Reviews a diff against BT.CPP v4 conventions — node base-class choice, non-blocking ticks, ports/blackboard typing, factory/plugin registration, XML v4, and the ROS 2 wrapper contract. Returns a punch list with file:line anchors, not a rewrite.
Use when a design decision touches Clean Architecture boundaries in a ROS 2 project — which layer a new behaviour belongs to, whether a port belongs in domain or application, whether a new node should be lifecycle-managed, whether to compose nodes or split packages. Returns an architectural recommendation with trade-offs, not implementation.
Use when a design decision touches the gz-sim ECS — where new state should live, which system phase should write it, how to avoid coupling, whether to add a component vs. a member variable, whether a new system should be split or merged with an existing one. Returns an architectural recommendation with trade-offs, not implementation.
Use proactively before opening any gz-sim PR. Reviews a diff against the project's C++17 style, ECS conventions, plugin registration patterns, CMake structure, test placement, Migration.md / Changelog.md expectations, and pre-commit configuration. Returns a punch list, not a rewrite.
Use proactively before opening a PR that adds or changes a ros2_control controller, broadcaster, or hardware component (incl. URDF <ros2_control> bringup). Reviews a diff against ros2_controllers / ros2_control_demos conventions — controller & hardware lifecycle, command/state interface configuration, real-time safety of update()/read()/write(), generate_parameter_library usage, pluginlib registration, chainable-controller correctness, URDF wiring, and tests. Returns a punch list with file:line anchors, not a rewrite.
Use proactively before opening any ROS 2 / Nav 2 PR. Reviews a diff against this template's Clean Architecture, ROS 2 communication, lifecycle, testing, and Nav 2 plugin conventions. Returns a punch list with file:line anchors, not a rewrite.
Use proactively before opening a PR that touches a VDA 5050 connector / fleet bridge. Reviews a diff against VDA 5050 v3.0.0 protocol compliance (topics, QoS, header rules, base/horizon, action state machine, schema validation) and the template's Clean Architecture for the MQTT↔Nav 2 bridge. Returns a punch list with file:line anchors, not a rewrite.
Build the colcon workspace (optionally a single package) and report the outcome.