ROS2 respawn

edit

Hello ROS2 community,

I'm currently playing around with the best way to respawn a node (ROS2 foxy). My current solution exists of two files (see below). The first file ("test_package_launch.py") defines the generate_launch_description() method. This file is invoked with "ros2 launch test_package test_package_launch.py". Within the launch file the ExecuteProcess invokes the second file ("test_package_respawn.py").

So far everything works fine and also it's working as expected. I just don't like the fact to have two files. Is there a way to do this in a single file?

Thanks Jeremy

test_package_launch.py:

import sys
import os

from launch import LaunchDescription
import launch
from launch.actions.execute_process import ExecuteProcess
from launch_ros.actions import Node
from launch import LaunchService
from ament_index_python.packages import get_package_share_directory

def callback_respawn(event, context):
    print("---------------------------------- on exit callback -------------------------------")

respawn_delay = 3
def generate_launch_description():
    return LaunchDescription([
        ExecuteProcess(
        cmd=[sys.executable, "test_package_respawn.py"],
        respawn=True, respawn_delay=respawn_delay, on_exit=callback_respawn,
        emulate_tty=True,
        output="screen"
        )
    ])

test_package_respawn.py:

#!/usr/bin/env python3

import os
import sys

from launch import LaunchDescription
from launch.actions.execute_process import ExecuteProcess
from launch.actions.shutdown_action import Shutdown
from launch.actions.timer_action import TimerAction
from launch_ros.actions import Node
from ament_index_python.packages import get_package_share_directory
from launch import LaunchService

config = os.path.join(
    get_package_share_directory('test_package'),
    'config',
    'config.yaml'
)

def launch_node():
    return LaunchDescription(
        [Node(
              package="test_package",
              executable="test_package_node",
              name="test_package",
              output="screen",
              emulate_tty=True,
              parameters=[config]
          )
      ]
    )

def main():
  print("------------------------- started node in respawn process -----------------------------")
  desc = launch_node()
  service = LaunchService()
  service.include_launch_description(desc)
  service.run()

if __name__ == '__main__':
  main()