For many packages, like Elasticsearch, Docker, or Jenkins, you need to install a trusted GPG key on your system before you can install from the official package repository.
Traditionally, you'd run a command like:
wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
But if you do that in modern versions of Debian or Ubuntu, you get the following warning:
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
This way of adding apt keys still works for now (in mid-2022), but will stop working in the next major releases of Ubuntu and Debian (and derivatives). So it's better to stop the usage now. In Ansible, you would typically use the
ansible.builtin.apt_key module, but even that module has the following deprecation warning: