Debian APT key management

A short story in 4 steps:

motivation:

apt-key is/is being deprecated.

question:

How to install keys for other repos - for example, mkusb being the case, but incl. other Ubuntu PPAs - in a organized, manageable and easy-to-reverse manner?

solution:

StackOverflow

example:

export GNUPGHOME="$(mktemp -d)"
gpg --recv-keys --keyserver keyserver.ubuntu.com 54B8C8AC
gpg --export 54B8C8AC | sudo tee /etc/apt/trusted.gpg.d/mkusb-archive-keyring.gpg
cat <<-SOURCE | sudo tee /etc/apt/sources.list.d/mkusb.list
    deb [signed-by=/etc/apt/trusted.gpg.d/mkusb-archive-keyring.gpg] http://ppa.launchpad.net/mkusb/ppa/ubuntu focal main
    SOURCE

downsides:

MySQL can, and will overwrite your apt list file.