Add custom base service config

config/base.scm

@@ -0,0 +1,19 @@
+(define-module (config base)
+  #:use-module (guix gexp)
+  #:use-module (gnu services)
+  #:use-module (gnu services base)
+  #:use-module (services chrony)
+  #:export (base-services))
+
+(define chrony-config "\
+  pool pool.ntp.org iburst
+  makestep 1.0 3
+  driftfile /var/lib/chrony/drift
+")
+
+(define (base-services)
+  (cons* (service chrony-service-type
+                  (chrony-configuration
+                    (config-file (plain-file "chrony.conf" chrony-config))
+                    (syscall-filter "1")))
+         %base-services))