How do I extend openssh-service-type ?

[Edouard Klein]

Hi !

I'm trying to make sense of:
https://guix.gnu.org/manual/en/guix.html#index-openssh_002dservice_002dtype

#+begin_quote
This service can be extended with extra authorized keys, as in this example:

(service-extension openssh-service-type
                   (const `(("charlie"
                             ,(local-file "charlie.pub")))))
#+end_quote

My goal is to do exactly that: add a public key to a user of an
operating system whose openssh-service-type is already configured
elsewhere.

I can do it by going to this "elsewhere" and adding the

("charlie"  ,(local-file "charlie.pub"))

in the authorized-keys field of the openssh-configuration, but when I
try to extend the service, the key is just ignored and does not appear
in /etc/ssh/authorized-keys.d/

I've tried adding a simple-service to the operating-system declaration
like so:

#+begin_src scheme
  (simple-service
   (format #f "ssh keys for user ~a" "toto")
   openssh-service-type
   (list
    `("toto" ,(local-file "toto.pub"))))
#+end_src

I also tried the verbose version:

#+begin_src scheme
 (service (service-type
                  (name 'tamereenslip)
                  (extensions
                   (list
                    (service-extension openssh-service-type
                                       (const `(("toto"
                                                 ,(local-file 
"toto.pub")))))))) #f)
#+end_src

I'm at my wit's end. I could not find any examples online or by grepping
the source code.

Has anybody ever been successful in extending the openssh-service ? If
so, could I please see your code ?

Thanks,

Edouard.