Quadlets have INI-like syntax, as they are based on systemd units. This is much simpler to reason about than YAML, used for podman-compose and docker-compose.
Extending a service is as simple as adding or removing a few lines and restarting the daemon and service.
Because the containers are internally run with podman, you can still manage them with podman as you wish. This is useful, for instance, if the container requires a restart after some internal modification to the container (like MediaWiki), or if it needs changes to its matching database (like WriteFreely).
Podman provides Pods, which allow to bundle groups of containers and, in addition to that, automatically insert them into the same network. Podman Pods require you to define ports and whatnot at Pod creation time, which can be impractical if you need to change your setup in the future. With Quadlets, you alter the container file, reload the daemon and restart the service.
The now deprecated podman-generate-systemd always generates complex and hard-to-read systemd service files. Quadlets do not have this issue.
Using podman-generate-systemd together with podman-compose is not very robust: after making drastic changes to a compose file and recreating the containers/ pods, the generated services will lose their ability to manage those containers. With Quadlets, container files have an inherent connection to their respective systemd services.
Systemd features are available to container files. Things like OnFailure=
to trigger another service if the current one fails, ExecStopPost= to run an
arbitrary command if the current service fails, container logs are stored in
journald
and are accessible via
journalctl,
containers can be managed together with
systemd timers,
etc. This allows for capabilities that are not possible or are difficult to do
with compose files. You can find more about this in the How To.
Because all processes related to the container are under the same service cgroup, systemd is able to manage it entirely, and changing the respective cgroup affects the entire container.