Following on previous discussions on the subject, a recent. release by Robotis for their Turtlebot3 Burger robot product has an implementation of the cv_camera package. Their instructions compile this package
http://wiki.ros.org/cv_camera which nicely publishes image_raw (sensor_msgs/Image) from a Pi Camera connected to /dev/video0, displayed with rqt_image_view on a ROS Desktop remote laptop screen. It works just fine on my WIP Turtlebot3 upgrade
This package is not released for FOXY, though I note a FOXY released package “ROS2_v4l2_camera”which refers to its use with the Raspberry Pi Camera. There we go something to try to give eyes to my Peavy/Nugen BV80 FOXY Neatobot.