src: add user session detection implementation

Detect user login and logout for Linux and Windows.

Report an active interactive session through the /refresh response
so a new ogserver instance can update the session status.

Poll the session change in 5 second intervals in a thread. Use the
same event socket previously used by the old session detection
mechanism to notify a session change.

Use the method check_interactive_session_change in each
ogOperations.py to report the session status.
Return values:
	None: no session changes are found
	True: login
	False: logout

Windows
Verify if psutil.users() has any value.

Linux
Verify all the psutil.users() asociated to a terminal.

src/linux/ogOperations.py

@@ -7,6 +7,7 @@
 # (at your option) any later version.
 
 import os
+import psutil
 import subprocess
 from subprocess import CalledProcessError
 from src.log import OgError
@@ -15,6 +16,9 @@ from src.ogRest import ThreadState
 
 class OgLinuxOperations:
 
+    def __init__(self):
+        self.session = False
+
     def _restartBrowser(self, url):
         raise OgError('Function not implemented')
 
@@ -66,4 +70,21 @@ class OgLinuxOperations:
         raise OgError('Function not implemented')
 
     def refresh(self, ogRest):
-        return {"status": "LINUX"}
+        if self.session:
+            session_value = 'LINUXS'
+        else:
+            session_value = 'LINUX'
+        return {"status": session_value}
+
+    def check_interactive_session_change(self):
+        old_status = self.session
+        has_logged_user = False
+        for user in psutil.users():
+            if user.terminal:
+                has_logged_user = True
+                break
+        self.session = has_logged_user
+
+        if self.session != old_status:
+            return self.session
+        return None

src/live/ogOperations.py

@@ -837,3 +837,6 @@ class OgLiveOperations:
 
         logging.info('Sending response to refresh request')
         return json_body
+
+    def check_interactive_session_change(self):
+        return False

src/ogClient.py

@@ -6,6 +6,7 @@
 # Free Software Foundation; either version 3 of the License, or
 # (at your option) any later version.
 
+import threading
 import errno
 import select
 import socket
@@ -26,6 +27,8 @@ class State(Enum):
 
 class ogClient:
 	OG_PATH = '/opt/opengnsys/'
+	SESSION_POLL_INTERVAL = 5
+	EVENT_SOCKET_PORT = 55885
 
 	def __init__(self, config):
 		self.CONFIG = config
@@ -36,7 +39,7 @@ class ogClient:
 		if self.mode in {'linux', 'windows'}:
 			self.event_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
 			self.event_sock.setblocking(0)
-			self.event_sock.bind(('127.0.0.1', 55885))
+			self.event_sock.bind(('127.0.0.1', ogClient.EVENT_SOCKET_PORT))
 		else:
 			self.event_sock = None
 
@@ -49,6 +52,25 @@ class ogClient:
 		self.ogrest = ogRest(self.CONFIG)
 		self.seq = None
 
+		self.session_check_thread = threading.Thread(target=self._session_check_loop, daemon=True)
+		self.session_check_thread.start()
+
+	def _session_check_loop(self):
+		while True:
+			session_status = self.ogrest.check_interactive_session_change()
+			if session_status is True:
+				message = "session start user"
+			elif session_status is False:
+				message = "session stop user"
+			else:
+				message = None
+
+			if message:
+				self.event_sock.sendto(message.encode('utf-8'),
+				                       ('127.0.0.1', ogClient.EVENT_SOCKET_PORT))
+
+			time.sleep(ogClient.SESSION_POLL_INTERVAL)
+
 	def get_socket(self):
 		return self.sock
 

src/ogRest.py

@@ -443,3 +443,6 @@ class ogRest():
 
 	def process_refresh(self, client):
 		threading.Thread(target=ogThread.refresh, args=(client, self,)).start()
+
+	def check_interactive_session_change(self):
+		return self.operations.check_interactive_session_change()

src/virtual/ogOperations.py

@@ -629,3 +629,6 @@ class OgVirtualOperations:
             for k, v in device_names.items():
                 f.write(f'{k}={v}\n')
             f.truncate()
+
+    def check_interactive_session_change(self):
+        return None

src/windows/ogOperations.py

@@ -8,6 +8,7 @@
 
 import os
 import ctypes
+import psutil
 import subprocess
 from subprocess import CalledProcessError
 import multiprocessing as mp
@@ -64,6 +65,7 @@ def create_systray():
 class OgWindowsOperations:
 
     def __init__(self):
+        self.session = False
         freeze_support()
         mp.set_start_method('spawn')
         self.systray_p = Process(target=create_systray, daemon=True)
@@ -122,4 +124,20 @@ class OgWindowsOperations:
         raise OgError('Function not implemented')
 
     def refresh(self, ogRest):
-        return {"status": "WIN"}
+        if self.session:
+            session_value = 'WINS'
+        else:
+            session_value = 'WIN'
+        return {"status": session_value}
+
+    def check_interactive_session_change(self):
+        old_status = self.session
+        has_logged_user = False
+        for user in psutil.users():
+            has_logged_user = True
+            break
+        self.session = has_logged_user
+
+        if self.session != old_status:
+            return self.session
+        return None