Handling OS variants

[Conan-Kudo]

In Fedora, each and every variant you download from the website is a semi-unique OS identifier through the combination of ID+VERSION_ID+VARIANT_ID in os-release(5).

From what I can tell at a glance, there doesn't seem to be a nice way to handle configuring variant fragments on top of common OS fragments to generate this information.

To give you an idea of what variants look like, here are two samples:

Fedora KDE:

NAME="Fedora Linux"
VERSION="41 (KDE Plasma)"
RELEASE_TYPE=stable
ID=fedora
VERSION_ID=41
VERSION_CODENAME=""
PLATFORM_ID="platform:f41"
PRETTY_NAME="Fedora Linux 41 (KDE Plasma)"
ANSI_COLOR="0;38;2;60;110;180"
LOGO=fedora-logo-icon
CPE_NAME="cpe:/o:fedoraproject:fedora:41"
DEFAULT_HOSTNAME="fedora"
HOME_URL="https://fedoraproject.org/"
DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora/f41/system-administrators-guide/"
SUPPORT_URL="https://ask.fedoraproject.org/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=41
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=41
SUPPORT_END=2025-12-15
VARIANT="KDE Plasma"
VARIANT_ID=kde

Fedora Workstation

NAME="Fedora Linux"
VERSION="41 (Workstation Edition)"
RELEASE_TYPE=stable
ID=fedora
VERSION_ID=41
VERSION_CODENAME=""
PLATFORM_ID="platform:f41"
PRETTY_NAME="Fedora Linux 41 (Workstation Edition)"
ANSI_COLOR="0;38;2;60;110;180"
LOGO=fedora-logo-icon
CPE_NAME="cpe:/o:fedoraproject:fedora:41"
DEFAULT_HOSTNAME="fedora"
HOME_URL="https://fedoraproject.org/"
DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora/f41/system-administrators-guide/"
SUPPORT_URL="https://ask.fedoraproject.org/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=41
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=41
SUPPORT_END=2025-12-15
VARIANT="Workstation Edition"
VARIANT_ID=workstation

[ikeycode]

I'd have to say you didn't look too closely then because we support base array in the core metadata to reference base-level products for inheritance purposes. What we can do is add a kind of registry mechanism in the Rust crate to automatically load the drop-ins such that os-release generation is automated, by having /usr/lib/os-info.json -> /usr/lib/os-info/os/fedora-workstation.json and base set to fedora-41 in /usr/lib/os-info/os/fedora-41.json for example.