The only reasons for wpa_action to be explicitly executed by the user is to stop wpa_cli from controlling ifupdown or reload the wpa_supplicant.conf file after editing. wpa_action eth1 stop Otherwise, wpa_action is given as an argument to a wpa_cli daemon.
wpa_cli -i eth1 -a /sbin/wpa_action -B
This can be done by using the wpa-roam option in the interfaces file. wpa-roam takes one argument, a user provided wpa_supplicant.conf file.
sudo /etc/init.d/networking restart
