apt-get update failed because certificate verification failed because handshake failed on nodesource
I experienced this error trying to add the keys for mongodb-org 4.0 to a docker container running Ubuntu 18.04. There was a problem with the certificates installed in this base image. I managed to fix it by install ca-certificates:
sudo apt install ca-certificates
You can add [trusted=yes] in the sources.list. For example:
deb [trusted=yes] http://ppa.launchpad.net/repo_name/pkg/ubuntu vivid main
deb-src [trusted=yes] http://ppa.launchpad.net/repo_name/pkg/ubuntu vivid main