Debugging XML-RPC calls « JavaDude's Groovy Snippets

January 12, 2010

Debugging XML-RPC calls

Filed under: Groovy Tutorial — Tags: debug, trac, xml-rpc — admin @ 7:59 am

The Groovy XML-RPC library 0.5 allows me to do perform basic authorization, but my Trac Server now throws a error code 500 at me (stating XML declaration not well-formed). Since I dont know how to check the XML request the library posts, I choose to dissect the messages at the network level using Wireshark. Luckily I have a Python library that works fine, so I can compare the working version of the XML-RPC request. (Remark: Dont forget to start wireshark as root user/sudo)

XML Error

2010-01-07 09:03:03,095 Trac[main] DEBUG: Dispatching <Request "POST u'/login/xmlrpc'">
2010-01-07 09:03:03,117 Trac[main] ERROR: Internal Server Error:
Traceback (most recent call last):
File "/usr/local/Python-2.5.2/lib/python2.5/site-packages/trac/web/main.py", line 441, in _dispatch_request
dispatcher.dispatch(req)
File "/usr/local/Python-2.5.2/lib/python2.5/site-packages/trac/web/main.py", line 205, in dispatch
resp = chosen_handler.process_request(req)
File "/usr/local/Python-2.5.2/lib/python2.5/site-packages/TracXMLRPC-1.0.6-py2.5.egg/tracrpc/web_ui.py", line 163, in process_request
self.process_xml_request(req, content_type)
File "/usr/local/Python-2.5.2/lib/python2.5/site-packages/TracXMLRPC-1.0.6-py2.5.egg/tracrpc/web_ui.py", line 167, in process_xml_request
args, method = xmlrpclib.loads(req.read(int(req.get_header('Content-Length'))))
File "/usr/local/Python-2.5.2/lib/python2.5/xmlrpclib.py", line 1130, in loads
p.feed(data)
File "/usr/local/Python-2.5.2/lib/python2.5/xmlrpclib.py", line 547, in feed
self._parser.Parse(data, 0)
ExpatError: XML declaration not well-formed: line 1, column 30
2010-01-07 09:03:03,121 Trac[chrome] DEBUG: Prepare chrome data for request

Python Library/Call

XML-RPC

import xmlrpclib
server = xmlrpclib.ServerProxy("http://user:password@sometracserver.com/login/xmlrpc")
print server.wiki.getPage("WikiStart")

Result in Wireshark

Wireshark

Groovy Call

XML-RPC

def serverProxy = new XMLRPCServerProxy("http://sometracserver.com/project/login/xmlrpc")
serverProxy.setBasicAuth("user","password")
serverProxy.wiki.getPage("WikiStart")

Result in Wireshark

Wireshark

There is the problem: encoding=”+ENCODING+”
The Trac XML reader most likely will throw up the complete call because of this. Actually the comparison was not really required because the error is very obvious.

JavaDude's Groovy Snippets

January 12, 2010

Debugging XML-RPC calls

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