did you try installing sudo apt-get install --reinstall ca-certificates and running add-apt-repository ppa:cloud-installer/testing ??

Little bit more info will be very helpful for advice. what os version you are using, are you able to access launchpad pages directly etc

I ran into this issue and was able to get the PPA installed by first installing JUJU and MAAS.

sudo apt-get install python-software-properties sudo add-apt-repository ppa:juju/stable sudo add-apt-repository ppa:maas/stable sudo add-apt-repository ppa:cloud-installer/stable sudo apt-get update

Hope this helps :)