# Launch File Setup

In order to properly evaluate competitors code, competitors will need to create a single ROS2 launch file that starts the competition, MoveIT if needed, and any competitor nodes. An example is shown below: 

``` python

from launch import LaunchDescription
from launch_ros.actions import Node
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.actions import IncludeLaunchDescription
from launch_ros.substitutions import FindPackageShare
from launch.substitutions import PathJoinSubstitution, LaunchConfiguration
from launch.conditions import IfCondition

from launch.actions import (
    DeclareLaunchArgument,
    OpaqueFunction,
)

from ariac_moveit_config.parameters import generate_parameters

def launch_setup(context, *args, **kwargs):
    # Launch arguments
    trial_name = LaunchConfiguration("trial_name")
    
    # Move Group
    moveit = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            [FindPackageShare("ariac_moveit_config"), "/launch", "/ariac_robots_moveit.launch.py"]
        )
    )

    # ARIAC_environment
    ariac_environment = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            [FindPackageShare("ariac_gazebo"), "/launch", "/ariac.launch.py"]
        ),
        launch_arguments={
            'trial_name': trial_name,
            'competitor_pkg': "nist_competitor",
            'sensor_config': "sensors"
        }.items()
    )

    # Test Competitor node
    test_competitor = Node(
        package="nist_competitor",
        executable="competitor",
        output="screen",
        parameters=generate_parameters(),
    )

    nodes_to_start = [
        test_competitor,
        ariac_environment,
        moveit
    ]

    return nodes_to_start

def generate_launch_description():
    declared_arguments = []


    declared_arguments.append(
        DeclareLaunchArgument("trial_name", default_value="kitting", description="Name of ariac trial")
    )

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

```

Two important things to note:

- Ensure that the launch arguments for the ariac_environment node are correct for your package
- Include the trial_name argument as a launch argument for the file and make sure that it is passed to the ariac_environment launch file as done above.