Using YAML with composable nodes with LoadNode

edit

Hey guys,

I'm using ROS2 galactic.

I was trying to load nodes into a component container node using the composition_interfaces::srv::LoadNode service. It turned out that I can't use my system YAML file in my composable nodes.

I noticed that it is somehow possible from a launch file (by passing a new YAML file in the parameters list of the ComposableNode object) as seen in this issue: #715

After some reverse engineering I found out that the launch script actually parses the yaml file and then pass a list of parameters in the service request.

Is there a way to pass a YAML file to the LoadNode service (without using a launch file)? In humble distro, is this behaviour different? I wish to have one executable which takes a single --params-file argument and have the parameters of all its composable nodes in there. That way I won't have to pass parameters for each node when loading them.