Because https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions suggests doing the "curl pipe bash" anti-pattern, let's try to make that cleaner.
Since containers are built from a definitive OS and Version we don't need the universality of that bash script.
If we examine closely, the https://deb.nodesource.com/setup_6.x we see that it really only does 2 things for Debian:
- Add [their public key][1] to apt's keychain via
apt-key add