runtime/rasms_moveit_config/launch/rasms_bringup.launch.py

from launch.actions.declare_launch_argument import DeclareLaunchArgument
from launch.launch_description import LaunchDescription
from launch.actions import IncludeLaunchDescription, OpaqueFunction
from launch.conditions import IfCondition
from launch.substitutions import Command, FindExecutable, PathJoinSubstitution
from launch.substitutions.launch_configuration import LaunchConfiguration
from launch_ros.actions import Node
from launch_ros.substitutions import FindPackageShare
from launch.launch_description_sources import PythonLaunchDescriptionSource
import xacro
import os
from ament_index_python import get_package_share_directory


def launch_setup(context, *args, **kwargs):

    # Evaluate frequently used variables
    model = LaunchConfiguration("model").perform(context)
    xacro_file = os.path.join(get_package_share_directory("rasms_description"),"urdf/","rasms_description.urdf.xacro")
    assert os.path.exists(xacro_file), "The xacro file of rasms_description doesnt exist"+str(xacro_file)
    robot_description = xacro.process_file(xacro_file)
    robot_description_content = robot_description.toxml()
    #print(robot_description_content)

    # Load controls
    control = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            PathJoinSubstitution([
                FindPackageShare("rasms_moveit_config"),
                "launch",
                "rasms_control.launch.py"
            ])
        ), launch_arguments=[
            ("robot_description", robot_description_content),
            ("controller_configurations_package", LaunchConfiguration("controller_configurations_package")),
            ("controller_configurations", LaunchConfiguration("controller_configurations")),
            ("controller", LaunchConfiguration("controller")),
            ("sim", LaunchConfiguration("sim"))
        ]
    )

    # Gazebo simulation 
    simulation = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            PathJoinSubstitution([
               FindPackageShare("rasms_moveit_config"),
                "launch",
                "rasms_simulation.launch.py"
            ])
        ), 
        launch_arguments=[
           ("robot_name", LaunchConfiguration("robot_name"))
        ],
        condition=IfCondition(LaunchConfiguration("sim"))
    )

    # Move group
    move_group = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            PathJoinSubstitution([
                FindPackageShare("rasms_moveit_config"),
                "launch",
                "rasms_moveit_interface.launch.py"
            ])
        ), 
        launch_arguments=[
            ("robot_description", robot_description_content),
            ("moveit_controller_configurations_package", LaunchConfiguration("moveit_controller_configurations_package")),
            ("moveit_controller_configurations", LaunchConfiguration("moveit_controller_configurations")),
            ("model", LaunchConfiguration("model")),
            ("sim", LaunchConfiguration("sim"))
        ]
    )

    return [
        simulation,
        control,
        move_group
    ]


def generate_launch_description():

    # Launch arguments
    launch_args = []

    launch_args.append(DeclareLaunchArgument(
        name="model",
        default_value="rasms_description",
        description="Desired LBR model. Use model:=iiwa7/iiwa14/med7/med14."
    ))

    launch_args.append(DeclareLaunchArgument(
        name="robot_name",
        default_value="rasms",
        description="Set robot name."
    ))

    launch_args.append(DeclareLaunchArgument(
        name="sim",
        default_value="true",
        description="Launch robot in simulation or on real setup."
    ))

    launch_args.append(
        DeclareLaunchArgument(
            name="controller_configurations_package",
            default_value="rasms_moveit_config",
            description="Package that contains controller configurations."
        )
    )

    launch_args.append(
        DeclareLaunchArgument(
            name="controller_configurations",
            default_value="config/rasms_controllers.yml",
            description="Relative path to controller configurations YAML file. Note that the joints in the controllers must be named according to the robot_name."
        )
    )

    launch_args.append(
        DeclareLaunchArgument(
            name="controller",
            default_value="position_trajectory_controller",
            description="Robot controller."
        )
    )

    launch_args.append(
        DeclareLaunchArgument(
            name="moveit_controller_configurations_package",
            default_value="rasms_moveit_config",
            description="Package that contains MoveIt! controller configurations."
        )
    )

    launch_args.append(
        DeclareLaunchArgument(
            name="moveit_controller_configurations",
            default_value="config/rasms_moveit_controllers.yml",
            description="Relative path to MoveIt! controller configurations YAML file. Note that the joints in the controllers must be named according to the robot_name. This file lists controllers that are loaded through the controller_configurations file."
        )
    )

    return LaunchDescription(
        launch_args + [
        OpaqueFunction(function=launch_setup)
    ])