GNS3 Launcher

Installing GNS3 on Ubuntu-based distros is easy:

sudo add-apt-repository ppa:gns3/ppa
sudo apt update
sudo apt install gns3-gui

After installation you can easily launch GNS3 from the Terminal, but if you were expecting a nice icon you could add to a dock or other location, you'll notice there isn't one.

To create a launcher for GNS3:

sudo vi /usr/share/applications/gns3.desktop

Insert the following lines:

[Desktop Entry]
Name=GNS3
Comment=Network Simulation Software
Exec=/usr/bin/gns3
Icon=/usr/share/app-install/icons/gns3.png
Terminal=false
Type=Application
Categories=Internet;

I use Numix Circle Icons on my system, so in place of the standard GNS3 icon specified above within the "Icon=" line, I use the following:

Icon=/usr/share/icons/Numix-Circle/48/apps/gns3.svg

When done, ensure that user/group is root:root and that the permissions are 644, and that's it. GNS3 should now show up when you search your applications. If you want to add the launcher to your desktop, simply copy gns3.desktop to ~/Desktop.