You can manage your CameraInfo yourself, the manager provides convenience functions for loading it from a url and a service for setting the calibration live. I've used CamearInfoManagers many times because the documentation and examples steers the reader to it - but I've only generated calibrations offline and my launch files would be more consistent if yaml locations came from a path via $(find foo_package) rather than mixing in a package://foo_package url, and http://wiki.ros.org/camera_calibration_parsers readCalibration()could be used directly.