Force connections to close when running overnight task

in case the task involves rebuilding current app DB

rattail/luigi/handler.py

@@ -185,7 +185,14 @@ class LuigiHandler(GenericHandler):
            but do not actually run it.
         """
         appdir = self.config.appdir()
-        env = {'PYTHONPATH': appdir}
+
+        # must preserve existing environ, but also add some things to it
+        env = dict(os.environ)
+        if 'PYTHONPATH' in env:
+            env['PYTHONPATH'] += os.pathsep + appdir
+        else:
+            env['PYTHONPATH'] = appdir
+
         if keep_config:
             env['RATTAIL_CONFIG_FILES'] = os.pathsep.join(self.config.files_read)
         else:
@@ -255,6 +262,18 @@ class LuigiHandler(GenericHandler):
             log.debug("dry-run mode, so aborting")
             return
 
+        # TODO: most overnight tasks can run okay, but occasionally we
+        # need an overnight task to rebuild the current app DB - i.e.
+        # drop the DB and re-clone from production.  in these cases we
+        # cannot afford to have lingering connections to the current
+        # DB or else dropping it may fail.  so our fix for now, is to
+        # foribly recreate the connection pool for all overnight task
+        # runs.  would be nice to be more selective but this seems to
+        # work okay for now...
+        pool = self.config.rattail_engine.pool
+        pool.dispose()
+        self.config.rattail_engine.pool = pool.recreate()
+
         # run command in subprocess
         curdir = os.getcwd()
         try: