It’s currently difficult to programmatically add a build-machine, because the
`service-extension' mechanism is the only facility which can do that. It
relies on the `guix-service-type', ala:
(service-extension guix-service-type
(guix-extension (build-machines (list ...))))
...but `guix-service-type' is already instantiated as part of
`%base-services', and replacing it may lose other configuration, like
substitute servers and authorized keys.
Additionally, a default value of `#f' for the build-machines field requires
guarding uses of the field with:
(or (guix-build-machines config) '())
Changing the default to be the empty list avoids that. One can now add
build-machines with code such as:
(modify-services %base-services
(guix-service-type
config =>
(guix-configuration
(inherit config)
(authorized-keys
(cons %build-machine-key
(guix-configuration-authorized-keys config)))
(build-machines (cons #~(build-machine ...)
(guix-configuration-build-machines config))))))
* gnu/services/base.scm (guix-configuration): Rename `guix-build-machines' to
`guix-configuration-build-machines' and export it. Change the default from
`#f' to the empty list.
* gnu/services/base.scm (guix-activation): Update the build-machines test and
reverse the conditions.
Change-Id: I6780c6a5579fd9d4b4f22ee2b2bf7ba7a0454407
Signed-off-by: Ludovic Courtès <ludo@gnu.org>
ef8ab6ab66