Hi,

I have an application where two nodes are created.

/app_ns/first_node
/second_node

As you can see, I'm specifying a namespace for one of the nodes, while the other has the default "". My goal, as the title says, is to add a namespace to both nodes, for example via command-line, but I'm open to other approaches.

What I would like to get is

/user_ns/app_ns/first_node
/user_ns/second_node

Unfortunately, the only way I know for specifying namespace is through the remapping arguments, which does not work in this case. For example I tried the following

$ ros2 run my_pkg my_app -r __ns:=/user_ns
$ ros2 node list
/user_ns/first_node
/user_ns/second_node

Do you know how could I get my desired output? I.e. how can I add/prepend a namespace while keeping whatever namespace the executable is already setting? Thank you

Costmap2DROS::Costmap2DROS(
const std::string & name,
const std::string & parent_namespace,
const std::string & local_namespace)
  : nav2_util::LifecycleNode(name, "", true,
  // NodeOption arguments take precedence over the ones provided on the command line
  // use this to make sure the node is placed on the provided namespace
  rclcpp::NodeOptions().arguments({
  "--ros-args", "-r", std::string("__ns:=") +
  nav2_util::add_namespaces(parent_namespace, local_namespace),
  "--ros-args", "-r", name + ":" + std::string("__node:=") + name
})),