core: local_dir can now be overrided (usefull to launch 2 instances at the same time)

src/core/sat_main.py

@@ -75,6 +75,13 @@ class SAT(service.Service):
 
     def get_const(self, name):
         """Return a constant"""
+        try:
+            _const = os.environ['SAT_CONST_%s' % name]
+            if _const:
+                debug(_("Constant %(name)s overrided with [%(value)s]") % {'name':name, 'value': _const})
+                return _const
+        except KeyError:
+            pass
         if not CONST.has_key(name):
             error(_('Trying to access an undefined constant'))
             raise Exception