This is derived from the official tutorial

1. Run this code:

   Note: We’re using ros-melodic-desktop-full

   #Setup your computer to accept software from packages.ros.org.
   sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
   
   #Set up your keys
   sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
   
   sudo apt update
   sudo apt install ros-melodic-desktop-full
   #sudo apt install ros-melodic-desktop
   #sudo apt install ros-melodic-ros-base
   
   #To find available packages, use:
   #apt search ros-melodic
   
   #It's convenient if the ROS environment variables are automatically added to your bash session every time a new shell is launched:
   echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
   echo "export EDITOR='nano -w'" >> ~/.bashrc #from https://wiki.ros.org/ROS/Tutorials/UsingRosEd
   source ~/.bashrc
   
   
   #To install tools and other dependencies for building ROS packages, run:
   sudo apt install python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential
   #not sure if you need to do the next line.
   #sudo apt install python3-rosdep python3-rosinstall python3-rosinstall-generator python3-wstool build-essential
   sudo apt install python-rosdep
   
   sudo rosdep init
   rosdep update
   

2. Install catkin tools

   sudo apt install -y catkin-tools
   sudo apt install -y python3-pip python3-yaml
   sudo pip3 install rospkg catkin_pkg empy
   

3. Take a Snapshot