Added an affirm(statement_string) function, which acts like an assert, and lets us trigger an email message with traceback when the statement to affirm is False. Use instead of assert if we still want the server to produce a response, even if something is seriously wrong.

- Legacy-Id: 12901

ietf/utils/log.py

@@ -1,20 +1,21 @@
 # Copyright The IETF Trust 2007, All Rights Reserved
 
-try:
-    import syslog
-    logger = syslog.syslog
-except ImportError:                     # import syslog will fail on Windows boxes
-    import logging
-    logging.basicConfig(filename='tracker.log',level=logging.INFO)
-    logger = logging.info
-
-    pass
-    
+import logging
 import inspect
 import os.path
 
+try:
+    import syslog
+    logfunc = syslog.syslog
+except ImportError:                     # import syslog will fail on Windows boxes
+    logging.basicConfig(filename='tracker.log',level=logging.INFO)
+    logfunc = logging.info
+    pass
+
 from django.conf import settings
 
+import debug                            # pyflakes:ignore
+
 def getclass(frame):
     cls = None
     argnames, varargs, varkw, defaults  = inspect.getargvalues(frame)
@@ -31,6 +32,7 @@ def getcaller():
     return (pmodule, pclass, pfunction, pfile, pline)
 
 def log(msg):
+    "Uses syslog by preference.  Logs the given calling point and message."
     if settings.SERVER_MODE == 'test':
         return
     if isinstance(msg, unicode):
@@ -45,6 +47,30 @@ def log(msg):
             where = " in " + func + "()"
     except IndexError:
         file, line, where = "/<UNKNOWN>", 0, ""
-    logger("ietf%s(%d)%s: %s" % (file, line, where, msg))
+    logfunc("ietf%s(%d)%s: %s" % (file, line, where, msg))
 
 
+
+logger = logging.getLogger('django')
+
+def affirm(statement):
+    """
+    This acts like an assertion.  It uses the django logger in order to send
+    the failed assertion and a backtrace as for an internal server error.
+
+    """
+    class Traceback():
+        pass
+    frame = inspect.stack()[1][0]
+    value = eval(statement, frame.f_globals, frame.f_locals)
+    if not value:
+        if settings.DEBUG is True:
+            raise AssertionError(statement)
+        else:
+            # build a simulated traceback object
+            tb = Traceback()
+            tb.tb_frame = frame
+            tb.tb_lasti = None
+            tb.tb_lineno = frame.f_lineno
+            tb.tb_next = None
+            logger.error("AssertionError: '%s'", statement, exc_info=(AssertionError, statement, tb), extra=frame.f_locals)