Hi Bruno, I have written some useful macros for transforming services as you describe here. You may find them useful:
https://lab.arctype.co/poseidon/poseidon-os/-/blob/master/poseidon/services/base.scm Sincerely, Ryan Sundberg Dec 28, 2022 8:48:15 AM mirai <mi...@makinata.eu>: > It is occasionally desired to have a service depend on additional shepherd > services > than the defaults listed in their definition. > > Examples where this can be seen is the shepherd-requirement field provided by > nginx-configuration and opensmtpd-configuration, but these fields are > record-type > specific and not available for the other service types (unless patched in). > > An alternative to patching the original record-type is to define a custom > service-type > record-type and inheriting it which is somewhat clunky for what amounts to a > setup-specific > single line change: > > --8<---------------cut here---------------start------------->8--- > (shepherd-service > ... > - (requirement `(...)) > + (requirement `(... ,@shepherd-requirement)) > --8<---------------cut here---------------end--------------->8--- > > Another type of extensibility that should be considered is the capability to > add extra > service-extensions to existing service-type records. > These can be useful for setup-specific (i.e. not applicable in general to be > included with Guix) scenarios, > for example, to add an extra activation-service-type extension or have a > special-files-service-type > extension that the service-type usually does not have. > > The current approach that I'm aware of to achieve something similar is through > simple-service, drawbacks being extra boilerplate code and a "disjoint" > service > whose connection to the "parent service" is not immediately apparent. > > --8<---------------cut here---------------start------------->8--- > ;; Ideally this should go in radicale-service-type > (simple-service 'chmod-radicale shepherd-root-service-type > (list (shepherd-service (requirement '(user-homes)) > (provision '(radicale-home)) > (documentation "chmod g+rwx > to user 'radicale' home.") > (one-shot? #t) > (start #~(lambda _ > (chmod > (passwd:dir (getpw "radicale")) #o770) > #t))))) > --8<---------------cut here---------------end--------------->8--- > > > Instead, what if the service procedure could be changed to accept optional > keyword arguments? > Then one could express the extensions and dependencies as: > > --8<---------------cut here---------------start------------->8--- > (services > (service foo-service-type > #:requirements '(networking nscd smtpd) > #:extensions (list (service-extension bar-service-type (lambda _ > ...)) > (service-extension activation-service-type > (lambda _ ...)))) > --8<---------------cut here---------------end--------------->8--- > > Thoughts? > > > Regards, > Bruno
