From d3fc01689f59786252c2a826ef2d89d30c77dfa5 Mon Sep 17 00:00:00 2001
From: l_samenv <l_samenv@samenv.psi.ch>
Date: Thu, 8 Apr 2021 10:21:44 +0200
Subject: [PATCH] improve more handling of errors when starting server

+ add shutdown method to server (and dispatcher)
---
 secop/protocol/dispatcher.py |  1 +
 secop/server.py              | 48 ++++++++++++++++++++++++------------
 2 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/secop/protocol/dispatcher.py b/secop/protocol/dispatcher.py
index e9296e2..2836342 100644
--- a/secop/protocol/dispatcher.py
+++ b/secop/protocol/dispatcher.py
@@ -82,6 +82,7 @@ class Dispatcher:
         self._subscriptions = {}
         self._lock = threading.RLock()
         self.restart = srv.restart
+        self.shutdown = srv.shutdown
 
     def broadcast_event(self, msg, reallyall=False):
         """broadcasts a msg to all active connections
diff --git a/secop/server.py b/secop/server.py
index 50a674f..fbb4ae2 100644
--- a/secop/server.py
+++ b/secop/server.py
@@ -29,6 +29,7 @@ import os
 import sys
 import threading
 import time
+import traceback
 from collections import OrderedDict
 
 from secop.errors import ConfigError, SECoPError
@@ -219,6 +220,10 @@ class Server:
             self._restart = True
             self.interface.shutdown()
 
+    def shutdown(self):
+        self._restart = False
+        self.interface.shutdown()
+
     def _processCfg(self):
         errors = []
         opts = dict(self.node_cfg)
@@ -227,31 +232,39 @@ class Server:
         if opts:
             errors.append(self.unknown_options(cls, opts))
         self.modules = OrderedDict()
-        badclass = None
+        failure_traceback = None  # traceback for the last error
         failed = set()  # python modules failed to load
         self.lastError = None
         for modname, options in self.module_cfg.items():
             opts = dict(options)
+            pymodule = None
             try:
                 classname = opts.pop('class')
                 pymodule = classname.rpartition('.')[0]
                 if pymodule in failed:
                     continue
                 cls = get_class(classname)
-                modobj = cls(modname, self.log.getChild(modname), opts, self)
-                # all used args should be popped from opts!
-                if opts:
-                    errors.append(self.unknown_options(cls, opts))
-                self.modules[modname] = modobj
-            except ConfigError as e:
-                errors.append(str(e))
             except Exception as e:
-                if str(e) == 'no such class':
-                    errors.append('%s not found' % classname)
+                if pymodule is None:
+                    if str(e) == 'no such class':
+                        errors.append('%s not found' % classname)
+                    else:
+                        raise
+                        errors.append(repr(e))
                 else:
                     failed.add(pymodule)
-                    badclass = classname
-                    errors.append('error importing %s' % pymodule)
+                    failure_traceback = traceback.format_exc()
+                    errors.append('error importing %s' % classname)
+            else:
+                try:
+                    modobj = cls(modname, self.log.getChild(modname), opts, self)
+                    # all used args should be popped from opts!
+                    if opts:
+                        errors.append(self.unknown_options(cls, opts))
+                    self.modules[modname] = modobj
+                except Exception as e:
+                    failure_traceback = traceback.format_exc()
+                    errors.append('error creating %s: %r' % (modname, e))
 
         poll_table = dict()
         # all objs created, now start them up and interconnect
@@ -276,7 +289,11 @@ class Server:
 
         # call init on each module after registering all
         for modname, modobj in self.modules.items():
-            modobj.initModule()
+            try:
+                modobj.initModule()
+            except Exception as e:
+                failure_traceback = traceback.format_exc()
+                errors.append('error initializing %s: %r' % (modname, e))
 
         if errors:
             for errtxt in errors:
@@ -285,9 +302,8 @@ class Server:
             # print a list of config errors to stderr
             sys.stderr.write('\n'.join(errors))
             sys.stderr.write('\n')
-            if badclass:
-                # force stack trace for import of last erroneous module
-                get_class(badclass)
+            if failure_traceback:
+                sys.stderr.write(failure_traceback)
             sys.exit(1)
 
         if self._testonly: