gazebo_ros2_control has been released on Foxy! This package provides a Gazebo plugin which instantiates a ros2_control controller manager and connects it to a Gazebo model. Check the README to learn how configure the new gazebo_ros2_control plugin.
There are some basic demos to check some of the ros2_controllers: joint_trayectory_controller, velocity_controller and effort_controller
There is a docker container available if you want to try it!