Is there a workaround to set QoS at launch time?

Question

I'm using composition to leverage IPC to convert ZED Cameras depth maps into virtual laser scans with the depthimage_to_laserscan package.

The problem is that the defauls QoS of the depthimage_to_laserscan::DepthImageToLaserScanROS component are not correctly set and I get this exception when starting the node:

component_container-3] [ERROR] [1701705850.520313066] [zed.zed_depth_to_laserscan]: Component constructor threw an exception: intraprocess communication is not allowed with a zero qos history depth value
[ERROR] [launch_ros.actions.load_composable_nodes]: Failed to load node 'depthimage_to_laserscan' of type 'depthimage_to_laserscan::DepthImageToLaserScanROS' in container '/zed/zed_depth_to_laserscan': Component constructor threw an exception: intraprocess communication is not allowed with a zero qos history depth value

Do you know any workaround to solve this problem?

This is the part of my launch file that generates the problem:

    # ZED Wrapper component
    zed_wrapper_component = ComposableNode(
        package='zed_components',
        namespace=camera_name_val,
        plugin='stereolabs::ZedCamera',
        name=zed_node_name,
        parameters=[
            # YAML files
            config_common_path,  # Common parameters
            config_camera_path,  # Camera related parameters
            # Overriding
            {
                'general.camera_name': camera_name_val,
                'general.camera_model': camera_model_val,
                'general.svo_file': svo_path,
                'general.serial_number': serial_number
            }
        ],
        extra_arguments=[{'use_intra_process_comms': True}]
    )

    # Depth to Laser scan component
    zed_cvt_component = ComposableNode(
        package='depthimage_to_laserscan',
        namespace=camera_name_val,
        plugin='depthimage_to_laserscan::DepthImageToLaserScanROS',
        name='depthimage_to_laserscan',
        parameters=[
            config_path_cvt,
            # Overriding
            {
                'output_frame': camera_depth_frame
            }],
        remappings=[
                ('depth', zed_node_name_val + '/depth/depth_registered'),
                ('depth_camera_info', zed_node_name_val + '/depth/camera_info')
            ],
        extra_arguments=[
            {
                'use_intra_process_comms': True
                }
            ]
    )

    # ROS 2 Component Container
    container = ComposableNodeContainer(
            name='zed_depth_to_laserscan',
            namespace=camera_name_val,
            package='rclcpp_components',
            executable='component_container',
            composable_node_descriptions=[
                zed_wrapper_component,
                zed_cvt_component
            ],
            output='screen',
    )
```

Answer 1

Actually, yes! The code just has to provide the QoS override as a valid option:

node->create_publisher(
  "chatter",
  KeepLast{10},
  QosOverridingOptions{true});  // allow_reconfigurable all qos

Then it can be set:

/my/ns/node_name:
  ros__parameters:
    qos_overrides:  # group for all the qos settings
      'my/fully/qualified/topic/name/here':
        publisher:
          reliability: reliable
          history_depth: 100
          history: keep_last

I'm of the personal belief that this override capability should be default to true but currently it needs to be explicitly set by the code to allow the launch-time configuration. This is available in Galactic and newer!