Before creating the URDF file for the robot, let's create an ROS package in the catkin workspace so that the robot model keeps using the following command:
$ catkin_create_pkg mastering_ros_robot_description_pkg roscpp tf
geometry_msgs urdf rviz xacro
The package mainly depends on the urdf and xacro packages. If these packages have not been installed on to your system, you can install them using the package manager:
$sudo apt-get install ros-kinetic-urdf $sudo apt-get install ros-kinetic-xacro
We can create the urdf file of the robot inside this package and create launch files to display the created urdf in RViz. The full package is available on the following Git repository; you can clone the repository for a reference to implement this package, or you can get the package from the book's source code:
$ git clone...