Added support for the infrastructure for on demand access/create the

server connection.

The BaseDriver and BaseConnection are two abstract classes, which allows
us to replace the existing driver with the currently used. The current
implementation supports to connect the PostgreSQL and Postgres Plus
Advanced Server using the psycopg2 driver.

web/pgadmin/__init__.py

@@ -19,7 +19,7 @@ from htmlmin.minify import html_minify
 from settings.settings_model import db, Role, User, Version
 from importlib import import_module
 from werkzeug.local import LocalProxy
-from pgadmin.utils import PgAdminModule
+from pgadmin.utils import PgAdminModule, driver
 from werkzeug.utils import find_modules
 import sys
 import os
@@ -34,8 +34,9 @@ class PgAdmin(Flask):
     def find_submodules(self, basemodule):
         for module_name in find_modules(basemodule, True):
             if module_name in self.config['MODULE_BLACKLIST']:
-                self.logger.info('Skipping blacklisted module: %s' %
-                                module_name)
+                self.logger.info(
+                        'Skipping blacklisted module: %s' % module_name
+                        )
                 continue
             self.logger.info('Examining potential module: %s' % module_name)
             module = import_module(module_name)
@@ -82,6 +83,7 @@ class PgAdmin(Flask):
                       for key, values in menu_items.items()}
         return menu_items
 
+
 def _find_blueprint():
     if request.blueprint:
         return current_app.blueprints[request.blueprint]
@@ -104,9 +106,10 @@ def create_app(app_name=config.APP_NAME):
     app.logger.setLevel(logging.DEBUG)
     app.logger.handlers = []
 
-    # We also need to update the handler on the webserver in order to see request.
-    # Setting the level prevents werkzeug from setting up it's own stream handler
-    # thus ensuring all the logging goes through the pgAdmin logger.
+    # We also need to update the handler on the webserver in order to see
+    # request. Setting the level prevents werkzeug from setting up it's own
+    # stream handler thus ensuring all the logging goes through the pgAdmin
+    # logger.
     logger = logging.getLogger('werkzeug')
     logger.setLevel(logging.INFO)
 
@@ -125,9 +128,9 @@ def create_app(app_name=config.APP_NAME):
     logger.addHandler(ch)
 
     # Log the startup
-    app.logger.info('################################################################################')
+    app.logger.info('########################################################')
     app.logger.info('Starting %s v%s...', config.APP_NAME, config.APP_VERSION)
-    app.logger.info('################################################################################')
+    app.logger.info('########################################################')
     app.logger.debug("Python syspath: %s", sys.path)
 
     ##########################################################################
@@ -149,7 +152,9 @@ def create_app(app_name=config.APP_NAME):
     # Setup authentication
     ##########################################################################
 
-    app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + config.SQLITE_PATH.replace('\\', '/')
+    app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///{0}'.format(
+            config.SQLITE_PATH.replace('\\', '/')
+            )
 
     # Only enable password related functionality in server mode.
     if config.SERVER_MODE is True:
@@ -200,7 +205,10 @@ def create_app(app_name=config.APP_NAME):
             # the sysadmin a hint. We'll continue to try to login anyway as
             # that'll through a nice 500 error for us.
             if user is None:
-                app.logger.error('The desktop user %s was not found in the configuration database.' % config.DESKTOP_USER)
+                app.logger.error(
+                        'The desktop user %s was not found in the configuration database.'
+                        % config.DESKTOP_USER
+                        )
                 abort(401)
 
             login_user(user)
@@ -224,11 +232,15 @@ def create_app(app_name=config.APP_NAME):
         """Inject a reference to the current blueprint, if any."""
         return {
             'current_app': current_app,
-            'current_blueprint': current_blueprint }
+            'current_blueprint': current_blueprint
+            }
+
+    # Load all available serve drivers
+    driver.init_app(app)
 
     ##########################################################################
     # All done!
     ##########################################################################
-
     app.logger.debug('URL map: %s' % app.url_map)
+
     return app