Support for systemd in apache::daily_restart.

The cron job created by the apache::daily_restart class used the
/sbin/service command explicitly to check if httpd is already running.
While at least RHEL-7/Fedora has a compatibility script that calls
systemctl, it is good form to use systemctl directly when we are
on a systemd-based OS.  Do so.  Also use systemctl status to give more
information when the restart failed.

manifests/init.pp

@@ -86,10 +86,25 @@ class apache::base
  */
 class apache::daily_restart
 {
+    $gracefulcmd = 'o=`/usr/sbin/apachectl graceful 2>&1`'
+    case $::initsystem
+    {
+	'sysvinit', 'upstart': {
+	    $statuscmd = '/sbin/service httpd status >/dev/null 2>&1'
+	    $extrastatus = 'echo "$o" >&2'
+	}
+	'systemd': {
+	    $statuscmd = '/bin/systemctl status httpd.service >/dev/null 2>&1'
+	    $extrastatus = '/bin/systemctl status -l httpd.service >&2'
+	}
+	default: {
+	    fail("${name}: Init system ${::initsystem} not supported")
+	}
+    }
     # This tries to only generate output (mailed to root by Cron) if
     # the restart fails.  And it will not try to start Apache if it is
     # not running.
-    $restart = '/sbin/service httpd status >/dev/null 2>&1 && (o=`/usr/sbin/apachectl graceful 2>&1` || echo "$o" >&2)'
+    $restart = "${statuscmd} && (${gracefulcmd} || ${extrastatus})"
 
     cron {
 	'apache::daily_restart':