Implement ros2 param check_sim_time verb

[techtasie]

Description

Fixes #1192

Is this user-facing behavior change?

ros2 param check_sim_time is a new verb.

usage: ros2 param check_sim_time [-h] [--spin-time SPIN_TIME] [-s] [--no-daemon] [--include-hidden-nodes] [--per-node-timeout N]

Check for all node the use_sim_time parameter

options:
  -h, --help            show this help message and exit
  --spin-time SPIN_TIME
                        Spin time in seconds to wait for discovery (only applies when not using an already running daemon)
  -s, --use-sim-time    Enable ROS simulation time
  --no-daemon           Do not spawn nor use an already running daemon
  --include-hidden-nodes
                        Consider hidden nodes as well
  --per-node-timeout N  Maximum wait time per node for list_parameters service call in seconds (default: 5.0)

Did you use Generative AI?

GPT-5.2 was used to format the output and help generate the test.

Additional Information

[fujitatomoya]

@techtasie thanks for bringing up the real use case and PR !

do we already have this in rolling source build? which can be applied to any parameter instead of use_sim_time, that is much better.

see also https://docs.ros.org/en/rolling/Tutorials/Beginner-CLI-Tools/Understanding-ROS2-Parameters/Understanding-ROS2-Parameters.html#ros2-param-get

root@tomoyafujita-B760M-Pro-RS-D4:~/ros2_ws/colcon_ws# ros2 param get use_sim_time
/launch_ros_720881:
  Boolean value is: False
/lc_client:
  Boolean value is: False
/lc_listener:
  Boolean value is: False
/lc_talker:
  Boolean value is: False

besides, i think this PR is not good precedent. we might end up having the other verbs like check_qos_override and so on including test cases. i do not think this is gonna scale that way... this eventually becomes the maintenance burden...

[techtasie]

@fujitatomoya Oh, I didn’t know about ros2 param get use_sim_time. Good to know!

But at least I found a bug in the current get-parameter helper:

--- a/ros2param/ros2param/api/__init__.py
+++ b/ros2param/ros2param/api/__init__.py
@@ -74,14 +74,14 @@ def call_describe_parameters(*, node, node_name, parameter_names=None):
     return response

-def call_get_parameters(*, node, node_name, parameter_names):
+def call_get_parameters(*, node, node_name, parameter_names, spin_timeout_sec=None):
     client = AsyncParameterClient(node, node_name)
     ready = client.wait_for_services(timeout_sec=5.0)
     if not ready:
         raise RuntimeError('Wait for service timed out waiting for '
                            f'parameter services for node {node_name}')
     future = client.get_parameters(parameter_names)
-    rclpy.spin_until_future_complete(node, future)
+    rclpy.spin_until_future_complete(node, future, timeout_sec=spin_timeout_sec)
     response = future.result()
     if response is None:
         raise RuntimeError('Exception while calling service of node '

There should be a timeout for the service request; otherwise, hung/unresponsive nodes can prevent this from completing, this is only a real problem if you want to request the config from multiple nodes.. I will write up a patch for that.

[fujitatomoya]

There should be a timeout for the service request; otherwise, hung/unresponsive nodes can prevent this from completing, this is only a real problem if you want to request the config from multiple nodes

that i am trying to address with #1185?

[techtasie]

@fujitatomoya thanks!