WSGILogger(..., ip_header='HTTP_X_FORWARDED_FOR', ...) kw arg

This new keyword argument allows to use headers such as X-Forwarded-For
for the 'host' field in your logging. This is useful if you run behind a
reverse proxy. You have to specify the header as it will be provided by
the WSGI environment, in this case it would be HTTP_X_FORWARDED_FOR.
All characters are in uppercase and dashes will be replaced by underscores.

If you don't specify the keyword argument, it defaults to None. Then, or
whenever the header is not found in the WSGI environment, the logged host
will default to the REMOTE_ADDR.

Author: pklaus

requestlogger/__init__.py

@@ -28,13 +28,14 @@
 class WSGILogger(object):
     """ This is the generalized WSGI middleware for any style request logging. """
 
-    def __init__(self, application, handlers, formatter=None, propagate=True, **kw):
+    def __init__(self, application, handlers, formatter=None, propagate=True, ip_header=None, **kwargs):
         self.formatter = formatter or WSGILogger.standard_formatter
         self.logger = logging.getLogger('requestlogger')
         self.logger.propagate = propagate
         self.logger.setLevel(logging.DEBUG)
         for handler in handlers:
             self.logger.addHandler(handler)
+        self.ip_header = ip_header
         self.application = application
 
     def __call__(self, environ, start_response):
@@ -52,7 +53,7 @@ def custom_start_response(status, response_headers, exc_info=None):
         retval = self.application(environ, custom_start_response)
         runtime = int((clock() - start) * 10**6)
         content_length = content_lengths[0] if content_lengths else len(b''.join(retval))
-        msg = self.formatter(status_codes[0], environ, content_length, rt_us=runtime)
+        msg = self.formatter(status_codes[0], environ, content_length, ip_header=self.ip_header, rt_us=runtime)
         self.logger.info(msg)
         return retval
 
@@ -80,7 +81,14 @@ def format_NCSA_log(status_code, environ, content_length, **kwargs):
 
         # Let's collect log values
         val = dict()
-        val['host'] = environ.get('REMOTE_ADDR', '')
+        ip_header = kwargs.get('ip_header', None)
+        if ip_header:
+            try:
+                val['host'] = environ.get(ip_header, '')
+            except:
+                val['host'] = environ.get('REMOTE_ADDR', '')
+        else:
+            val['host'] = environ.get('REMOTE_ADDR', '')
         val['logname'] = '-'
         val['user'] = '-'
         date = dt.now(tz=Local)
@@ -102,19 +110,19 @@ def format_NCSA_log(status_code, environ, content_length, **kwargs):
         return FORMAT.format(**val)
 
     @staticmethod
-    def format_with_response_time(*args, **kw):
+    def format_with_response_time(*args, **kwargs):
         """
-          The dict kw should contain 'rt_us', the response time in milliseconds.
+          The dict kwargs should contain 'rt_us', the response time in milliseconds.
           This is the format for TinyLogAnalyzer:
           https://pypi.python.org/pypi/TinyLogAnalyzer
         """
-        rt_us = kw.get('rt_us')
-        return ApacheFormatters.format_NCSA_log(*args) + " {0}/{1}".format(int(rt_us/1000000), rt_us)
+        rt_us = kwargs.get('rt_us')
+        return ApacheFormatters.format_NCSA_log(*args, **kwargs) + " {0}/{1}".format(int(rt_us/1000000), rt_us)
 
 
-def log(handlers, formatter=ApacheFormatter(), **kw):
+def log(handlers, formatter=ApacheFormatter(), **kwargs):
     """Decorator for logging middleware."""
     def decorator(application):
-        return WSGILogger(application, handlers, **kw)
+        return WSGILogger(application, handlers, **kwargs)
     return decorator