I install ros kinetic and gazebo8 as the instruction in http://gazebosim.org/tutorials/?tut=ros_wrapper_versions#Gazebobuiltfromsource

After I compile the turtlebotgazebo from source. I start the lanuch in turtlebotgazebo.

But it seemed that the node /gazebo is not subscribing /mobile_base/commands/velocity (works in gazebo7/2 with ros indigo). Then how can I control the turtlebot in gazebo through ros?