add history writer

Change-Id: I2d577dcf0c543c26680d157be959b0a608ace759

secop/server.py

@@ -42,6 +42,7 @@ except ImportError:
 from secop.errors import ConfigError
 from secop.lib import formatException, get_class, getGeneralConfig
 from secop.modules import Attached
+from secop.params import PREDEFINED_ACCESSIBLES
 
 try:
     import systemd.daemon
@@ -126,7 +127,7 @@ class Server:
             else:
                 filename = None
         if filename is None:
-            raise ConfigError("Couldn't find cfg file %r" % cfgfile)
+            raise ConfigError("Couldn't find cfg file %r in %s" % (cfgfile, cfg['confdir']))
         self.log.debug('Parse config file %s ...' % filename)
         result = OrderedDict()
         parser = configparser.ConfigParser()
@@ -270,3 +271,10 @@ class Server:
             if not event.wait(timeout=max(0, deadline - time.time())):
                 self.log.info('WARNING: timeout when starting %s' % name)
         self.log.info('all modules and pollers started')
+        history_path = os.environ.get('FRAPPY_HISTORY')
+        if history_path:
+            from secop.histwriter import HistWriter
+            writer = HistWriter(history_path, PREDEFINED_ACCESSIBLES.keys(), self.dispatcher)
+            # treat writer as a connection
+            self.dispatcher.add_connection(writer)
+            writer.init(self.dispatcher.handle_describe(writer, None, None))