Q: Subscribe to a Gazebo topic and publish in a ROS node

A: If you are working with that [turtlebot3 simulation](https://turtlebot3.readthedocs.io/en/latest/simulation.html), you don’t have to subscribe a gazebo topic, since the simulation is configured already with ROS.

To subscribe the laser scanner and publish something else in the same node, you can do the following:

Create a pkg with these dependencies