Launch the server in a different process

To achieve this, a new method "wait_session_to_load" is
implemented in the SessioHelper class, which blocks the execution
until a server session (any server session) is loaded.

The SessionHelper does not create a new session on instantiation.
Now the caller has to explicitly ask the helper to load a session
or create a new one.

agkyra/gui.py

@@ -81,11 +81,15 @@ class GUI(WebSocketBaseClient):
 
 def run():
     """Prepare SessionHelper and GUI and run them in the proper order"""
-    helper = SessionHelper()
-    gui = GUI(helper.session)
-
     LOG.info('Start SessionHelper session')
-    helper.start()
+    subprocess.Popen([
+        os.path.join(CURPATH, 'scripts/cli.py'), 'launch_server'])
+
+    LOG.info('Client blocks until session is ready')
+    session = SessionHelper().wait_session_to_load()
+    assert session, 'UI server failed to load...'
+    LOG.info('Server session is ready, setup the GUI session')
+    gui = GUI(session)
 
     try:
         LOG.info('Start GUI')
@@ -93,8 +97,6 @@ def run():
     except KeyboardInterrupt:
         LOG.info('Shutdown GUI')
         gui.clean_exit()
-    LOG.info('Shutdown SessionHelper server')
-    helper.shutdown()
 
 if __name__ == '__main__':
     logging.basicConfig(filename='agkyra.log', level=logging.DEBUG)

agkyra/protocol.py

+#!/usr/bin/env python
+
 # Copyright (C) 2015 GRNET S.A.
 #
 # This program is free software: you can redistribute it and/or modify
@@ -46,12 +48,14 @@ class SessionHelper(object):
 
         LOG.debug('Connect to db')
         self.db = sqlite3.connect(self.session_db)
+
         self._init_db_relation()
-        self.session = self._load_active_session() or self._create_session()
+        # self.session = self._load_active_session() or self._create_session()
 
-        self.db.close()
+        # self.db.close()
 
     def _init_db_relation(self):
+        """Create the session relation"""
         self.db.execute('BEGIN')
         self.db.execute(
             'CREATE TABLE IF NOT EXISTS %s ('
@@ -59,7 +63,7 @@ class SessionHelper(object):
             ')' % self.session_relation)
         self.db.commit()
 
-    def _load_active_session(self):
+    def load_active_session(self):
         """Load a session from db"""
         r = self.db.execute('SELECT * FROM %s' % self.session_relation)
         sessions = r.fetchall()
@@ -71,7 +75,7 @@ class SessionHelper(object):
                 return dict(ui_id=last[0], address=last[1])
         return None
 
-    def _create_session(self):
+    def create_session(self):
         """Create session credentials"""
         ui_id = sha1(os.urandom(128)).hexdigest()
 
@@ -84,6 +88,7 @@ class SessionHelper(object):
             server_class=WSGIServer,
             handler_class=WebSocketWSGIRequestHandler,
             app=WebSocketWSGIApplication(handler_cls=WebSocketProtocol))
+        WebSocketProtocol.server = server
         server.initialize_websockets_manager()
         address = 'ws://%s:%s' % (LOCAL_ADDR, server.server_port)
         self.server = server
@@ -96,6 +101,19 @@ class SessionHelper(object):
 
         return dict(ui_id=ui_id, address=address)
 
+    def wait_session_to_load(self, timeout=20, step=2):
+        """Wait while the session is loading e.g. in another process
+            :returns: the session or None if timeout
+        """
+        time_passed = 0
+        while time_passed < timeout:
+            self.session = self.load_active_session()
+            if self.session:
+                return self.session
+            time_passed += step
+            time.sleep(step)
+        return None
+
     def start(self):
         """Start the helper server in a thread"""
         if getattr(self, 'server', None):
@@ -167,7 +185,7 @@ class WebSocketProtocol(WebSocket):
     """
 
     ui_id = None
-    db, session_db, session_relation = None, None, None
+    session_db, session_relation = None, None
     accepted = False
     settings = dict(
         token=None, url=None,
@@ -180,13 +198,12 @@ class WebSocketProtocol(WebSocket):
     essentials = ('url', 'token', 'container', 'directory')
 
     def heartbeat(self):
-        if not self.db:
-            self.db = sqlite3.connect(self.session_db)
+        db = sqlite3.connect(self.session_db)
         while True:
-            self.db.execute('BEGIN')
-            self.db.execute('UPDATE %s SET beat="%s" WHERE ui_id="%s"' % (
+            db.execute('BEGIN')
+            db.execute('UPDATE %s SET beat="%s" WHERE ui_id="%s"' % (
                 self.session_relation, time.time(), self.ui_id))
-            self.db.commit()
+            db.commit()
             time.sleep(2)
 
     def _get_default_sync(self):
@@ -404,10 +421,11 @@ class WebSocketProtocol(WebSocket):
     def clean_db(self):
         """Clean DB from session traces"""
         LOG.debug('Remove session traces')
-        self.db = sqlite3.connect(self.session_db)
-        self.db.execute('BEGIN')
-        self.db.execute('DELETE FROM %s' % self.session_relation)
-        self.db.commit()
+        db = sqlite3.connect(self.session_db)
+        db.execute('BEGIN')
+        db.execute('DELETE FROM %s' % self.session_relation)
+        db.commit()
+        db.close()
 
     def send_json(self, msg):
         LOG.debug('send: %s' % msg)
@@ -424,6 +442,7 @@ class WebSocketProtocol(WebSocket):
                     LOG.debug('Wait open syncs to complete')
                     self.syncer.wait_sync_threads()
                 self.close()
+                Thread(target=self.server.shutdown).start()
                 return
             {
                 'start': self.start_sync,

agkyra/scripts/cli.py

@@ -30,10 +30,11 @@ import logging
 LOGFILE = os.path.join(AGKYRA_DIR, 'agkyra.log')
 LOGGER = logging.getLogger('agkyra')
 HANDLER = logging.FileHandler(LOGFILE)
-FORMATTER = logging.Formatter("%(name)s %(levelname)s:%(asctime)s:%(message)s")
+FORMATTER = logging.Formatter(
+    "[CLI]%(name)s %(levelname)s:%(asctime)s:%(message)s")
 HANDLER.setFormatter(FORMATTER)
 LOGGER.addHandler(HANDLER)
-LOGGER.setLevel(logging.INFO)
+LOGGER.setLevel(logging.DEBUG)
 
 
 def main():
@@ -43,4 +44,14 @@ def main():
 
 
 if __name__ == "__main__":
-    main()
+    if sys.argv[1] in ('launch_server', ):
+        # This piece of code will stay here until the CLI can launch a server
+        # by itself
+        from agkyra.protocol import SessionHelper
+        LOGGER.debug('Please start the session helper')
+        helper = SessionHelper()
+        if not helper.load_active_session():
+            helper.create_session()
+            helper.server.serve_forever()
+    else:
+        main()

agkyra/scripts/gui.py

@@ -33,7 +33,7 @@ HANDLER = logging.FileHandler(LOGFILE)
 FORMATTER = logging.Formatter("%(name)s %(levelname)s:%(asctime)s:%(message)s")
 HANDLER.setFormatter(FORMATTER)
 LOGGER.addHandler(HANDLER)
-LOGGER.setLevel(logging.INFO)
+LOGGER.setLevel(logging.DEBUG)
 
 
 def main():