Bug report

The default_server_timeout parameter in bt_navigator is always overridden by the server_timeout port in each BT action node.

As a result, the default_server_timeout never takes effect because the server_timeout in each BT action node is mandatory and supersedes the default value.

Please refer to
https://github.com/ros-navigation/navigation2/blob/main/nav2_behavior_tree/include/nav2_behavior_tree/bt_action_server_impl.hpp#L185

The code

    server_timeout_ = config().blackboard->template get<std::chrono::milliseconds>("server_timeout");
    getInput<std::chrono::milliseconds>("server_timeout", server_timeout_);

may be changed as follows:

if (!getInput<std::chrono::milliseconds>("server_timeout", server_timeout_)) {
    server_timeout_ = config().blackboard->template get<std::chrono::milliseconds>("server_timeout");
}

Required Info:

• Operating System:
  • Ubuntu 22.04
• ROS2 Version:
  • Humble binaries
• Version or commit hash:
  • Main
• DDS implementation:
  • Fast-RTPS

Steps to reproduce issue

1. Create a Behavior Tree (BT) action node in a Nav2 configuration file.
2. Set a default server_timeout value in the corresponding YAML file.
3. Execute the BT with the action node.
4. Observe that the default value of server_timeout from the YAML file is not applied.

// Code in bt_action_node.hpp:
server_timeout_ = config().blackboard->template get<std::chrono::milliseconds>("server_timeout");
getInput<std::chrono::milliseconds>("server_timeout", server_timeout_);

Expected behavior

The default value of server_timeout specified in the YAML file should be applied unless overridden by a specific BT action node configuration.

Actual behavior

The default value of server_timeout from the YAML file is never applied because server_timeout_ is required to be explicitly set for each BT action node, which overrides the default.

Additional information

This bug prevents the default server_timeout value specified in the YAML configuration from being used in BT action nodes. As a result, users must manually set server_timeout for each node, leading to potential inconsistencies and additional configuration overhead.