1 # Copyright (C) 2014 Ipsilon Project Contributors
3 # See the file named COPYING for the project license
11 def log_request_response():
12 '''Log the contents of the request and subsequent response.
14 This is run as a tool hook and should be run as the last hook
15 (on_end_resource) just before the server writes the response to
16 the client. The tool is registered like this:
18 cherrypy.tools.log_request_response = \
19 cherrypy.Tool('on_end_resource', log_request_response)
21 Then the logging can be enabled or disabled via the config option,
22 for example to turn the logging on via a config dict add this
25 'tools.log_request_response.on': True,
27 or for a config file add this line:
29 tools.log_request_response.on = True
31 At first blush it would seem easy to log the request received and
32 the response emitted, just hook those locations and output the raw
33 data. Unfortunately there are no such locations in cherrypy where
34 you have access to the raw input and output data. The complicating
37 * Input data is consumed by the Request object off a file object
38 which cannot seek back (i.e. rewind), once the data is read it
39 cannot be read again. Therefore any attempt to log the raw input
40 will starve read operations done by the Request object to read
43 * Automatic consumption and processing of the body contents is
44 enabled by default (controlled by the
45 request.process_request_body config option). You generally do
46 not want to turn these automatic request processors off because
47 they provide valuable input processing useful to the request
48 processing pipeline (e.g. when Content-Type is
49 application/x-www-form-urlencoded, or multipart/form-data or
50 multipart). Most cherrypy page handlers expect this
51 pre-processing to have been performed and the 'cooked' data to
52 be availabe on the Request object. Thus rather than logging the
53 raw input HTTP which will have been consumed by the request
54 processing logic we are forced into logging only the 'cooked'
55 values available to us after the request has been read and
58 * The response body may not be available if response streaming is
59 enabled. This is because control is passed directly to the
60 object writing the data to the client bypassing the normal
61 cherrypy hooks. Fortunately streaming is not recommended and we
62 can expect it will be disabled. When streaming is disabled the
63 response body can be composed as:
67 - a generator yielding chunks of strings
69 When the response body is a string or list of strings logging
70 the body and then passing down the pipeline to be written to the
71 client is trivial. However when part of the body is produced by
72 a generator we must run the generator to produce that part of
73 the body and store it as a string. This is an issue equivalent
74 to not being able to re-read a file object as seen in the input
75 situation. Once the generator has run it cannot be run
76 again. Therefore we consume all the body output, store it in a
77 string, log it and then replace the request body contents with
78 the body string we formed. It's this body string which is
79 subsequently sent down the processing pipeline to be written to
84 #--- Begin local functions ---
86 def indent_text(text, level=0, indent=' '):
88 Input is a block of text potentially containing newlines which
89 seperate the text into a sequence of lines. The text block is
90 split into individual lines and indented according to the
91 indentation level. The width of the indent is controlled by
92 the optional indent parameter.
94 The result is a single block of text where each of the
95 original lines of text are indented.
98 f = cStringIO.StringIO()
100 lines = text.split('\n')
102 # Do not output trailing newline
103 if lines and lines[-1] == '':
107 f.write(indent*level)
111 string = f.getvalue()
115 def print_part(part):
117 Format a cherrypy._cpreqbody.Part object into a string.
119 When the request Content-Type is a multipart cherrypy splits
120 each part of the multipart into a Part object containing
121 information about the part and it's content.
123 f = cStringIO.StringIO()
125 f.write(indent_text('Name = %s\n' % part.name))
127 f.write(indent_text('Headers:\n'))
128 for name, value in part.headers.items():
129 f.write(indent_text('%s: %s\n' % (name, value), 1))
131 f.write(indent_text("Body:\n"))
132 f.write(indent_text(part.fullvalue(), 1))
134 string = f.getvalue()
138 def collapse_body(body):
139 '''The cherrypy response body can be:
143 * generator yielding a string
145 Generators are typically used for file contents but any
146 cherrypy response is permitted to use a generator to provide
147 the body of the response.
149 Strings and lists of strings are immediately available and
150 stored in the request object. During normal cherrypy
151 processing when writing the response to the client response
152 data which is provided by a generator will be iterated over
153 and written to the client. In order for us to be able to log
154 all the response data prior to it being sent to the client we
155 must also iterate over the generator provided content, however
156 this exhausts the generator making it unavailable to be
157 written to the client.
159 To solve this problem we collect all the response data. Now we
160 have the full body contents, we can log it and then set this
161 as the new body contents for remainder of the processing
162 pipeline to act upon (i.e. sent to the client)
164 f = cStringIO.StringIO()
169 string = f.getvalue()
173 #--- End local functions ---
175 f = cStringIO.StringIO()
176 request = cherrypy.serving.request
177 remote = request.remote
182 f.write(indent_text("<Request> [%s] %s\n" % \
183 (remote.name or remote.ip, request.request_line), 0))
187 f.write(indent_text("Headers:\n", 1))
188 for name, value in request.headers.items():
189 f.write(indent_text("%s: %s\n" % (name, value), 2))
191 # Request parameters from URL query string and
192 # x-www-form-urlencoded POST data
193 if request.body.params:
194 f.write(indent_text("Params:\n", 1))
195 for name, value in request.body.params.items():
196 # Multi-valued paramater is in a list
197 if isinstance(value, list):
198 for i, item in enumerate(value):
199 # Might be a multipart Part object, if so format it
200 if isinstance(item, cherrypy._cpreqbody.Part):
201 f.write(indent_text("%s[%s]:\n" % (name, i), 2))
202 f.write(indent_text(print_part(item), 3))
204 # Not a mulitpart, just write it as a string
205 f.write(indent_text("%s[%s]: %s\n" % (name, i, item), 2))
207 # Just a string value
208 f.write(indent_text("%s: %s\n" % (name, value), 2))
210 # If the body is multipart format each of the parts
211 if request.body.parts:
212 f.write(indent_text("Body Parts:\n"))
213 for i, part in enumerate(request.body.parts):
214 f.write(indent_text("Part %s name=%s:\n" % (i, part.name), 3))
215 f.write(indent_text(print_part(part), 4))
220 response = cherrypy.response
221 f.write(indent_text("<Response> %s\n" % response.status, 0))
223 # Log the response headers
224 if response.header_list:
225 f.write(indent_text("Headers:\n", 1))
226 for name, value in response.header_list:
227 f.write(indent_text("%s: %s\n" % (name, value), 2))
229 # Log the response body
231 # We can only do this if the response is not streaming because we have
232 # no way to hook the streaming content.
233 f.write(indent_text("Body:\n", 1))
236 f.write(indent_text("body omitted because response is streaming\n", 2))
238 response.body = collapse_body(response.body)
239 for chunk in response.body:
240 f.write(indent_text(chunk, 2))
242 string = f.getvalue()
246 cherrypy.tools.log_request_response = cherrypy.Tool('on_end_resource', log_request_response)
253 buf = cStringIO.StringIO()
255 stack = traceback.extract_stack()
256 traceback.print_list(stack[:-2], file=buf)
258 stacktrace_string = buf.getvalue()
260 return stacktrace_string
263 def get_class_from_frame(frame_obj):
266 http://stackoverflow.com/questions/2203424/
267 python-how-to-retrieve-class-information-from-a-frame-object
269 At the frame object level, there does not seem to be any way
270 to find the actual python function object that has been
273 However, if your code relies on the common convention of naming
274 the instance parameter of a method self, then you could do this.
277 args, _, _, value_dict = inspect.getargvalues(frame_obj)
278 # Is the functions first parameter named 'self'?
279 if len(args) and args[0] == 'self':
280 # in that case, 'self' will be referenced in value_dict
281 instance = value_dict.get('self', None)
284 return getattr(instance, '__class__', None)
285 # return None otherwise
290 frame = inspect.stack()[2]
293 line_number = frame[2]
296 # Only report the last 3 components of the path
297 filename = os.sep.join(filename.split(os.sep)[-3:])
299 cls = Log.get_class_from_frame(frame_obj)
301 location = '%s:%s %s.%s()' % \
302 (filename, line_number, cls.__name__, func)
304 location = '%s:%s %s()' % (filename, line_number, func)
308 def debug(self, fact):
309 if cherrypy.config.get('debug', False):
310 location = Log.call_location()
311 cherrypy.log('DEBUG(%s): %s' % (location, fact))
313 # for compatibility with existing code
319 def error(self, fact):
320 cherrypy.log.error('ERROR: %s' % fact)
321 if cherrypy.config.get('stacktrace_on_error', False):
322 cherrypy.log.error(Log.stacktrace())