Hi Pierre!

>> So, in your snippet, I should replace certbot-*-hook with "/etc/desec/hook.sh",
>> right?
> 
> Is the "hook.sh" script copied directly from the desec-certbot-hook
> package? In which case, I think you'll want to use `file-append` to
> directly refer to the package's script, something like this?
> 
> --8<---------------cut here---------------start------------->8---
> (authentication-hook (file-append desec-certbot-hook "/etc/hook.sh")
> (cleanup-hook (file-append desec-certbot-hook "/etc/hook.sh")
> --8<---------------cut here---------------end--------------->8---

The package is not in Guix yet (#47840). For now, manually downloaded 
the script and placed it in /etc/desec.

I tried the following and it worked,

(service certbot-service-type
   (certbot-configuration
     (email "admin@raghavgururajan.name")
     (certificates
       (list
         (certificate-configuration
           (domains '("raghavgururajan.name" "*.raghavgururajan.name"))
           (challenge "dns")
           (authentication-hook "/etc/desec/hook.sh")
           (cleanup-hook "/etc/desec/hook.sh"))))))

I was wondering how to generate certs with custom CSR, provided by some 
hosting-providers. Any ideas?

Regards,
RG.