There has been discussions in the past about stopping releasing (open)slam_gmapping in ROS distributions in favor of more performant SLAM approaches like karto or cartographer, so not sure if it should be ported to ROS 2.
Some packages have been already (partially?) ported:
- laser_geometry: branch
ros2of https://github.com/ros-perception/laser_geometry - depth_image_to_laserscan: branch
ros2https://github.com/ros2/depthimage_to_laserscan.git (should likely be moved to the upstream repository) - pcl_conversions: original port on
ros2branch of https://github.com/ros2/pcl_conversions.git (before ROS 1 repositories were merged)