Partly fixes <https://issues.guix.gnu.org/76315>.

Fixes a bug whereby a service whose canonical name has changed would not
be restarted—e.g., if '(syslogd) has a replacement providing
'(system-log syslogd).

* gnu/services/shepherd.scm (shepherd-service-upgrade)[running?]:
Remove.
[to-restart]: Change to a subset of LIVE.  Look up all the names of each
element of TARGET.
* guix/scripts/system/reconfigure.scm (upgrade-shepherd-services):
TO-RESTART is now a list of <live-service>; adjust accordingly.
* tests/services.scm ("shepherd-service-upgrade: one unchanged, one upgraded, one new"):
("shepherd-service-upgrade: service depended on is not unloaded"):
("shepherd-service-upgrade: obsolete services that depend on each other"):
("shepherd-service-upgrade: transient service"): Adjust accordingly.
("shepherd-service-upgrade: service has new canonical name"): New test.

Reported-by: Tomas Volf <~@wolfsden.cz>
Change-Id: I7cec495b4e824da5fad5518f039607cf92f935d9

This patch reverts the behavior introduced in
181951207339508789b28ba7cb914f983319920f which caused ‘modify-services’
clauses to only match a single instance of a service.

We will now match all service instances when doing a deletion or update, while
still raising an exception when trying to match against a service that does
not exist in the services list, or which was deleted explicitly by a ‘delete’
clause (or an update clause that returns ‘#f’ for the service).

Fixes: #64106

* gnu/services.scm (%modify-services): New procedure.
(modify-services): Use it.
(apply-clauses): Add DELETED-SERVICES argument, change to modify one service
at a time.
* tests/services.scm
("modify-services: delete then modify")
("modify-services: modify then delete")
("modify-services: delete multiple services of the same type")
("modify-services: modify multiple services of the same type"): New tests.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>
Modified-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>

Fixes <https://issues.guix.gnu.org/63921>.

The regression was introduced in
dbbc7e946131ba257728f1d05b96c4339b7ee88b, which changed the order of
services.  As a result, someone using 'modify-services' could find
themselves with incorrect ordering of expressions in the "boot" script,
whereby the cleanup expressions would come after (execl ".../shepherd").
This, in turn, would lead shepherd to error out at boot with EADDRINUSE
on /var/run/shepherd/socket.

* gnu/services.scm (%delete-service, %apply-clauses): Remove.
(clause-alist): New macro.
(apply-clauses): New procedure.
(modify-services): Use it.  Adjust docstring.
* tests/services.scm ("modify-services: do nothing"): Remove 'sort' call.
("modify-services: delete service"): Likewise, and add 't4' service.
("modify-services: change value"): Remove 'sort' call and fix expected value.

* tests/services.scm ("modify-services: delete non-existing service")
("modify-services: change value for non-existing service"): New tests.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

* tests/services.scm ("modify-services: do nothing")
("modify-services: delete service")
("modify-services: change value"): New tests.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

* gnu/services.scm (<service-type>)[description]: Remove default value.
* tests/services.scm: Add 'description' field to each 'service-type' form.

This is a followup to eeb8ac43c8c0b0cc69422766070dbefc55f5c5c1.

* tests/services.scm ("shepherd-service-upgrade: transient service"):
New test.

This is a followup to a2c759c8304c461d096ab763568e7f71546ff4e8.

* guix/scripts/system/reconfigure.scm (running-services): Fill in the
'transient?' field of <live-service>.
* tests/services.scm ("shepherd-service-upgrade: one unchanged, one upgraded, one new")
("shepherd-service-upgrade: service depended on is not unloaded")
("shepherd-service-upgrade: obsolete services that depend on each
other"): Adjust calls to 'live-service'.

* guix/scripts/system/reconfigure.scm: New file.
* Makefile.am (MODULES): Add it.
* guix/scripts/system.scm (bootloader-installer-script): Export variable.
* gnu/machine/ssh.scm (switch-to-system, upgrade-shepherd-services)
(install-bootloader): Delete variable.
* gnu/machine/ssh.scm (deploy-managed-host): Rewrite procedure.
* gnu/services/herd.scm (live-service): Export variable.
* gnu/services/herd.scm (live-service-canonical-name): New variable.
* tests/services.scm (live-service): Delete variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

Fixes a regression introduced in
c2dcff41c2e47f5f978f467864d5ed7829939884, whereby many tests in
'tests/packages.scm' would trigger a syntax error due to duplicate field
intializers in forms like:

  (dummy-package "foo" (version "0"))

* guix/tests.scm (dummy-package, dummy-origin): Rewrite to inherit from
a base record.  This restores the semantics from before
c2dcff41c2e47f5f978f467864d5ed7829939884.
* tests/services.scm ("instantiate-missing-services, indirect"): Remove
duplicate 'extensions' field.