improve error messages when attached modules fail on startup

Change-Id: Ic1d2d77de2574043749ddbc00def48a6fe77b2bd

frappy/secnode.py

@@ -30,6 +30,10 @@ from frappy.version import get_version
 from frappy.modules import Module
 
 
+class InitFailed(Exception):
+    pass
+
+
 class SecNode:
     """Managing the modules.
 
@@ -85,11 +89,15 @@ class SecNode:
             if not modobj.initModuleDone:
                 self.errors.append(f'{modobj.initModule.__qualname__} was not '
                                    f'called, probably missing super call')
+        except InitFailed:
+            raise
         except Exception as e:
             if self.traceback_counter == 0:
                 self.log.exception(traceback.format_exc())
             self.traceback_counter += 1
             self.errors.append(f'error initializing {modulename}: {e!r}')
+            modobj._initfailed = True
+            raise InitFailed('try to access erroneous module')
         modobj._isinitialized = True
         self.log.debug('initialized module %r', modulename)
         return modobj
@@ -101,8 +109,11 @@ class SecNode:
         When creating a new module, srv.module_config is accessed to get the
         modules configuration.
         """
-        if modulename in self.modules:
-            return self.modules[modulename]
+        modobj = self.modules.get(modulename)
+        if modobj:
+            if modobj._initfailed:
+                raise InitFailed('try to access erroneous module')
+            return modobj
         if modulename in list(self.modules.values()):
             # it's actually already the module object
             return modulename
@@ -205,8 +216,11 @@ class SecNode:
     def build_descriptive_data(self):
         modules = {}
         result = {'modules': modules}
-        for modulename in self.modules:
-            modobj = self.get_module(modulename)
+        for modulename in list(self.modules):
+            try:
+                modobj = self.get_module(modulename)
+            except InitFailed:
+                continue
             if not modobj.export:
                 continue
             # some of these need rework !