Bug report

Required Info:

• Operating System:
• Ubuntu 20.04
• ROS2 Version:
  • Foxy binaries
• Version or commit hash:
  • ros-foxy-navigation2 0.4.7-1focal.20220307.024942
• DDS implementation:
  • rmw_cyclonedds.

Steps to reproduce issue

Hi guys,
while loading a map it occurs that whenever I use

ros2 launch nav2_bringup bringup_launch.py map:=/path/to/map.yaml

the map server works. But as soon as I add a param file without any map_server param inside the file but with the map param

ros2 launch nav2_bringup bringup_launch.py params_file:=/path/to/params.yaml map:=/path/to/map.yaml 

it crashes. As soon as I add

 map_server:
   ros__parameters:
     use_sim_time: False
     yaml_filename: "xyz.yaml"

to the yaml file and start it with

ros2 launch nav2_bringup bringup_launch.py params_file:=/path/to/params.yaml map:=/path/to/map.yaml 

it works.

Issues:

• I cannot launch the file even tough I defined a map in the yaml file as the map parameter is compulsory.
• The yaml file parameter is not used and can be different to the map parameter used with CLI.

Feature request

Feature description

It would be nice to use only one parameter when starting. As the map parameter is always expected when launching the node it should only start with this one and should not require anything given in the param-file.