OCI-backed Guix System Services

[paul]

Dear Guixers,

I was recently inspired from Nix's oci-container feature and wrote a thin wrapper around the docker CLI to enable the management of docker containers through Shepherd [0]. This enables handling of non packaged services through guix system reconfigure and herd start/stop/status .

(define (grafana-configuration config)
  (oci-container-configuration
    (image "grafana/grafana:10.0.1")
    (network "host")
    (ports
      `((,port . "3000")))
    (volumes
      `(("/var/lib/grafana" . "/var/lib/grafana")
        ;; Needed because grafana.ini is a symlink to an item in the store.
        ("/gnu/store" . "/gnu/store")
        ("/etc/grafana/grafana.ini" . "/etc/grafana/grafana.ini")))))

(define grafana-service-type
  (service-type (name 'grafana)
                (extensions (list (service-extension oci-container-service-type
                                                     grafana-configuration)
                                  (service-extension account-service-type
                                                     (const %grafana-accounts))
                                  (service-extension nginx-service-type
                                                     grafana-nginx-locations)
                                  (service-extension activation-service-type
                                                     %grafana-activation)))))

This is somewhat made up code, for a real world example you can have a look here [1].

In the future it probably makes sense to be able to switch the "OCI backend" to podman, for now I just wanted to figure out if it's something that would be useful to the Guix community and if the implementation looks right.

To conclude, I'm not advocating for adding OCI-backed services to Guix mainstream: in my opinion they should be bootstrapped and built from source, but I believe the actual "backend" implementation for such services could be useful to have in Guix. What do you think?

Thank you for the wonderful community that Guix still proves to be,

giacomo

[0]: https://gitlab.com/orang3/small-guix/-/blob/master/small-guix/services/docker.scm

[1]: https://gitlab.com/orang3/guix-nas/-/blob/main/modules/nas/services/grafana.scm