Support systemd in the service module.

Most of it worked already, except for the enable parameter, because it
tried to use chkconfig which only sees SysV services. First look for
systemctl and use that if it exists.

library/service

@@ -32,7 +32,7 @@ def _find_binaries(m):
     global CHKCONFIG
     global INITCTL
     paths = ['/sbin', '/usr/sbin', '/bin', '/usr/bin']
-    binaries = [ 'service', 'chkconfig', 'update-rc.d', 'initctl']
+    binaries = [ 'service', 'chkconfig', 'update-rc.d', 'initctl', 'systemctl']
     location = dict()
 
     for binary in binaries:
@@ -44,7 +44,9 @@ def _find_binaries(m):
                 location[binary] = path + '/' + binary
                 break
 
-    if location.get('chkconfig', None):
+    if location.get('systemctl', None):
+        CHKCONFIG = location['systemctl']
+    elif location.get('chkconfig', None):
         CHKCONFIG = location['chkconfig']
     elif location.get('update-rc.d', None):
         CHKCONFIG = location['update-rc.d']
@@ -142,17 +144,16 @@ def _do_enable(name, enable):
     # we change argument depending on real binary used
     # update-rc.d wants enable/disable while
     # chkconfig wants on/off
-    valid_argument = dict({'on' : 'on', 'off' : 'off'})
-
+    # also, systemctl needs the arguments reversed
     if CHKCONFIG.endswith("update-rc.d"):
-        valid_argument['on'] = "enable"
-        valid_argument['off'] = "disable"
+        args = (CHKCONFIG, name, "enable" if enable else "disable")
+    elif CHKCONFIG.endswith("systemctl"):
+        args = (CHKCONFIG, "enable" if enable else "disable", name + ".service")
+    else:
+        args = (CHKCONFIG, name, "on" if enable else "off")
 
     if enable is not None:
-        if enable:
-            rc, stdout, stderr = _run("%s %s %s" % (CHKCONFIG, name, valid_argument['on']))
-        else:
-            rc, stdout, stderr = _run("%s %s %s" % (CHKCONFIG, name, valid_argument['off']))
+        rc, stdout, stderr = _run("%s %s %s" % args)
 
     return rc, stdout, stderr