How to import PPA repository keys to Ubuntu

Sometime, one needs to add additional software repositories to the exisiting Ubuntu installion. I recently had to add “cinnamon” reposity to Ubuntu from the launchpad. Everthing worked well excet the software packages from the cinnamon repository did not get listed in the Ubuntu software list. It showed an error message that the key is not found. If you are not a techie or a geek then adding the key to validate softwares downloaded from a particular repository is tricky. I spent some time learing how add it and many methods failed, so I detail the best winning method here.

There is a script to add all the missing key of the PPA repositories of Ubuntu. Copy the following commands and paste in the terminal and press enter. When prompted, give the password.

sudo apt-add-repository ppa:nilarimogard/webupd8

sudo apt-get update

sudo apt-get install launchpad-getkeys

The programme is now installed. This programme is handy when you add PPA repositories through software center. When you add repositories through syanptics package manager, the keys are not added into it by default.

sudo launchpad-getkeys

Run this programme by typing the following command in the terminal and it will check all the missing keys and will imoport the needed keys into the repository. If there are no missing keys, it will says so.