I learned this from an ansible molecule test env setup script for use in containers and VMs years ago; because `which` isn't necessarily installed in containers

I learned this from an ansible molecule test env setup script for use in containers and VMs years ago; because `which` isn't necessarily installed in containers for example: type -p apt && (set -x; apt install -y debsums; debsums | grep -v 'OK$') || \ type -p rpm && rpm -Va # --verify --all dnf reads .repo files from /etc/yum.repos.d/ [1] which have various gpg options; here's an /etc/yum.repos.d/fedora-updates.repo: [updates] name=Fedora $releasever - $basearch - Updates #baseurl=http://download.example/pub/fedora/linux/updates/$releasever/Everything/$basearch/ metalink=https://mirrors.fedoraproject.org/metalink?repo=updates-released-f$releasever&arch=$basearch enabled=1 countme=1 repo_gpgcheck=0 type=rpm gpgcheck=1 metadata_expire=6h gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch skip_if_unavailable=False From the dnf conf docs [1], there are actually even more per-repo gpg options: gpgkey gpgkey_dns_verification repo_gpgcheck localpkg_gpgcheck gpgcheck 1. https://dnf.readthedocs.io/en/latest/conf_ref.html#repo-options https://dnf.readthedocs.io/en/latest/conf_ref.html#repo-opti... 2. https://docs.ansible.com/ansible/latest/collections/ansible/builtin/yum_repository_module.html#parameter-gpgcakey https://docs.ansible.com/ansible/latest/collections/ansible/... lists a gpgcakey parameter for the ansible.builtin.yum_repository module For Debian, Ubuntu, Raspberry Pi OS and other dpkg .deb and apt distros: man sources.list man sources.list | grep -i keyring -C 10 # trusted: # signed-by: # /etc/apt/ trusted.gpg.d/ man apt-secure man apt-key apt-key help less "$(type -p apt-key)" signing-apt-repo-faq: https://github.com/crystall1nedev/signing-apt-repo-faq https://github.com/crystall1nedev/signing-apt-repo-faq From "New requirements for APT repository signing in 24.04" (2024) https://discourse.ubuntu.com/t/new-requirements-for-apt-repository-signing-in-24-04/42854 https://discourse.ubuntu.com/t/new-requirements-for-apt-repo... : > In Ubuntu 24.04, APT will require repositories to be signed using one of the following public key algorithms: [ RSA with at least 2048-bit keys, Ed25519, Ed448 ] > This has been made possible thanks to recent work in GnuPG 2.4 82 by Werner Koch to allow us to specify a “public key algorithm assertion” in APT when calling the gpgv tool for verifying repositories.