config/shepherd: Add redshift service.

.config/shepherd/services.scm

@@ -140,6 +140,22 @@ be missing."
     #:stop (make-system-destructor "pkill mcron")
     #:respawn? #t))
 
+(define location-paris "48.51:2.20")
+(define redshift                        ; TODO: Test!
+  (make <service>
+    #:provides '(redshift)
+    #:docstring "Redshift adjusts the color temperature of your screen according
+to your surroundings.  This may help your eyes hurt less if you are working in
+front of the screen at night."
+    #:start (make-system-constructor
+             (format #f "redshift -l ~a -t 6500:3500" location-paris)
+              #:log-file (string-append
+                           (or (getenv "XDG_CONFIG_HOME")
+                               (string-append (getenv "HOME") "/.config"))
+                           "/redshift/redshift.log"))
+    #:stop (make-kill-destructor)
+    #:respawn? #t))
+
 (define main-services (list
                        privoxy
                        auto-mount
@@ -152,7 +168,8 @@ be missing."
                           numlock
                           xbindkeys
                           no-bell
-                          auto-lock))
+                          auto-lock
+                          redshift))
 
 (define laptop-services (list
                          xbindkeys))