`bt_navigator_***_rclcpp_node` - Allow remapping

[roncapat]

Feature request

Allow to remap the node name (currently generated as /bt_navigator_ + navigator_name + _rclcpp_node) as something else, or at least move it in an arbitrary namespace.

Currently,

navigation2/nav2_behavior_tree/include/nav2_behavior_tree/bt_action_server_impl.hpp

Lines 140 to 148 in 7f561b0

	auto options = rclcpp::NodeOptions().arguments(
	{"--ros-args",
	"-r",
	std::string("__node:=") +
	std::string(node->get_name()) + "_" + client_node_name + "_rclcpp_node",
	"-p",
	"use_sim_time:=" +
	std::string(node->get_parameter("use_sim_time").as_bool() ? "true" : "false"),
	"--"});

since NodeOptions are built from scratch, I belive there is not enough flexibility in configuring that node IMHO.

[SteveMacenski]

What is your intended use-case so I can understand better? Would you need this to be different to run multiple instances (in which case could the name be randomized with a UUID)?

Keep in mind this line which allows this node to share all parameters given to the main node to be shared here. This is what lets you specify any information you want in the bt_navigator and have it be accessible in your BT ROS 2 node instance.

What do you need to do that isn't right now possible with it so I can make a suggestion

[roncapat]

What is your intended use-case so I can understand better? Would you need this to be different to run multiple instances (in which case could the name be randomized with a UUID)?

Briefly, just having full control over:

• the node name (and eventually its namespace)
• topic/services/action remappings of bt nodes

[SteveMacenski]

We could have the namespace from the main node added here in the NodeOptions population. That’s one is pretty easy!

We had a PR recently for the costmap internal node to enable remappings. Can that be applied here? https://github.com/ros-navigation/navigation2/blob/main/nav2_costmap_2d/src/costmap_2d_ros.cpp#L114

I think that covers everything except for the node renaming. Is that that important?

[roncapat]

We could have the namespace from the main node added here in the NodeOptions population. That’s one is pretty easy!

This one would help for sure partitioning my system.

We had a PR recently for the costmap internal node to enable remappings. Can that be applied here?
https://github.com/ros-navigation/navigation2/blob/main/nav2_costmap_2d/src/costmap_2d_ros.cpp#L114

This one is interesting too!

I think that covers everything except for the node renaming. Is that that important?

Well, it would be the cherry on the cake, but with namespacing I could be already quite happy.
Even if I find the suffix "_rclcpp_node" a bit redundant (if I do ros2 node list I already expect only nodes to be listed). Maybe you have historical reasons to keep this.

[SteveMacenski]

Maybe you have historical reasons to keep this.

Yeah, I would not like to change that since that would break anyone's parameter files inserting parameters into that. Unfortunately that name is just how it is for the time being until or if we can remove it (or do a very large refactor).

Can you open a PR to add in the namespacing and the getChildNodeOptions work? I think getChildNodeOptions could be added actually as a node util in nav2_utils then do it can be used in all locations. :-)

[SteveMacenski]

@roncapat I think this is related to your other questions (ish). What's the status?

[roncapat]

Working on it right now