live: rewrite poweroff operation

Replace legacy bash script /opt/opengnsys/client/scripts/poweroff with a
Python native solution.

Use subprocess module for any required external program when shutting
down a client. ethtool is used to ensure WoL setting is correct before
shutting down.

ogLive does not properly use a init system so busybox is used when
shutting down the system. In other live environments poweroff operation
just calls /sbin/poweroff.

src/live/ogOperations.py

@@ -190,12 +190,29 @@ class OgLiveOperations:
             with open(logfile, 'wb', 0) as f:
                 f.truncate(0)
 
+    def _poweroff_oglive(self):
+        interface = os.getenv('DEVICE')
+        cmd_ethtool = shlex.split(f'ethtool -s {interface} wol g')
+        cmd_browser = shlex.split('pkill -9 browser')
+        if not shutil.which('busyboxOLD'):
+            busybox = 'busybox'
+        else:
+            busybox = shutil.which('busyboxOLD')
+        cmd_busybox = shlex.split(f'{busybox} poweroff')
+
+        umount_all()
+        umount_cache()
+        if subprocess.run(cmd_ethtool).returncode != 0:
+            logging.error('Error running ethtool subprocess')
+        if subprocess.run(cmd_browser).returncode != 0:
+            logging.error('Error terminating ogBrowser process')
+        if subprocess.run(cmd_busybox) != 0:
+            logging.error('Error running "busybox poweroff" subprocess')
+
     def poweroff(self):
         logging.info('Powering off client')
         if os.path.exists('/scripts/oginit'):
-            cmd = f'source {ogClient.OG_PATH}etc/preinit/loadenviron.sh; ' \
-                  f'{ogClient.OG_PATH}scripts/poweroff'
-            subprocess.call([cmd], shell=True, executable=OG_SHELL)
+            self._poweroff_oglive()
         else:
             subprocess.call(['/sbin/poweroff'])