installer: Recommend 'ntp-service-type' for non-graphical systems.

We had several bug reports with a root cause of "the clock was
incorrect" from users who used the installer to install a non-graphical
Guix System.

* gnu/installer/services.scm (%system-services): Add the ntp-service-type.
* gnu/installer/newt/services.scm (run-system-administration-cbt-page): New
variable.
(run-services-page): Use run-system-administration-cbt-page when not
installing a desktop.
* gnu/installer/tests.scm (choose-services): Add and use a
choose-misc-service?  procedure.
* gnu/tests/install.scm (installation-target-os-for-gui-tests)<services>: Add
ntp-service-type.

1 files changed, 9 insertions, 0 deletions

diff --git a/gnu/installer/tests.scm b/gnu/installer/tests.scm
index 5d931149b8..3c049a1c85 100644
--- a/gnu/installer/tests.scm
+++ b/gnu/installer/tests.scm
@@ -221,7 +221,11 @@ ROOT-PASSWORD, and USERS."
                           (choose-network-management-tool?
                            (lambda (service)
                              (string-contains service "DHCP")))
+                          (choose-misc-service?
+                           (lambda (service)
+                             (string-contains service "NTP")))
                           (choose-other-service? (const #f)))
+
   "Converse over PORT to choose services."
   (define desktop-environments '())
 
@@ -243,6 +247,11 @@ ROOT-PASSWORD, and USERS."
      (null? desktop-environments)
      (find choose-network-management-tool? services))
 
+    ((checkbox-list (title "Console services") (text _)
+                    (items ,services))
+     (null? desktop-environments)
+     (filter choose-misc-service? services))
+
     ((checkbox-list (title "Printing and document services") (text _)
                     (items ,services))
      (filter choose-other-service? services))))