Description

XMLRPC requests fail when MoinMoin is invoked via the WSGI server. These was tested with the CherryPy WSGI server and wsgiref.

Versions: Python 2.5.2, MoinMoin 1.6.3, CherryPy 3.0.3.

With CherryPy, the request times out and fails.

With wsgiref, the request hangs forever.

Testing was performing using both Python and Ruby XMLRPC clients. The results were the same in both cases.

Steps to reproduce

Create a WSGI server instance. This example uses wsgiref:
- ```
   1 #!/webworks/wiki/bin/python
   2 
   3 # Straight from the CherryPy WSGI server code docs
   4 #
   5 
   6 import os
   7 import sys
   8 import logging
   9 import MoinMoin.server.server_wsgi
  10 
  11 # Specify path to wiki instance
  12 #
  13 wiki_path = '/Users/allums/wiki.flipnotics'
  14 
  15 # Configure MoinMoin
  16 #
  17 
  18 # MoinMoin 'wikiconfig.py' in sys.path
  19 #
  20 sys.path.insert(0, wiki_path)
  21 
  22 # Initialize MoinMoin logging
  23 #
  24 class Config(MoinMoin.server.server_wsgi.WsgiConfig):
  25     logPath = os.path.join(wiki_path, 'logs/moin.log')
  26     loglevel_file = logging.INFO # None
  27     loglevel_stderr = None
  28 
  29 config = Config() # you MUST create an instance to initialize logging!
  30 
  31 # Launch server
  32 #
  33 server_name = 'localhost'
  34 server_host = '127.0.0.1'
  35 server_port = 8080
  36 
  37 from wsgiref.simple_server import make_server
  38 
  39 httpd = make_server(server_host, server_port, MoinMoin.server.server_wsgi.moinmoinApp)
  40 
  41 if __name__ == '__main__':
  42     try:
  43         httpd.serve_forever()
  44     except KeyboardInterrupt:
  45         pass
```

Attempt any simple XMLRPC request, such as getPage():

   1 import xmlrpclib
   2 
   3 
   4 # Replace URL with server running FastCGI
   5 url = "http://localhost:8080/?action=xmlrpc2"
   6 server = xmlrpclib.ServerProxy(url, verbose=True)
   7 result = server.getPage("FrontPage")
   8 print result

Example

See #2 above.

Component selection

I believe the defect is occurring in the MoinMoin WSGI application, though the thing is so simple, I don't see how that could be the case.

Details

MoinMoin Version	1.6.3
OS and Version	Mac OS X 10.4.11
Python Version	2.5.2
Server Setup	wsgiref and/or CherryPy WSGI server
Server Details	None.
Language you are using the wiki in (set in the browser/UserPreferences)	English

wsgiref Server:

Request simply hangs until killed, which produces this client-side traceback.

connect: (localhost, 8080)
connect fail: ('localhost', 8080)
connect: (localhost, 8080)
send: 'POST /?action=xmlrpc2 HTTP/1.0\r\nHost: localhost:8080\r\nUser-Agent: xmlrpclib.py/1.0.1 (by www.pythonware.com)\r\nContent-Type: text/xml\r\nContent-Length: 160\r\n\r\n'
send: "<?xml version='1.0'?>\n<methodCall>\n<methodName>getPage</methodName>\n<params>\n<param>\n<value><string>FrontPage</string></value>\n</param>\n</params>\n</methodCall>\n"
^CTraceback (most recent call last):
  File "wsgi_debug.py", line 8, in <module>
    result = server.getPage("FrontPage")
  File "/webworks/wiki/lib/python2.5/xmlrpclib.py", line 1147, in __call__
    return self.__send(self.__name, args)
  File "/webworks/wiki/lib/python2.5/xmlrpclib.py", line 1437, in __request
    verbose=self.__verbose
  File "/webworks/wiki/lib/python2.5/xmlrpclib.py", line 1185, in request
    errcode, errmsg, headers = h.getreply()
  File "/webworks/wiki/lib/python2.5/httplib.py", line 1199, in getreply
    response = self._conn.getresponse()
  File "/webworks/wiki/lib/python2.5/httplib.py", line 928, in getresponse
    response.begin()
  File "/webworks/wiki/lib/python2.5/httplib.py", line 385, in begin
    version, status, reason = self._read_status()
  File "/webworks/wiki/lib/python2.5/httplib.py", line 343, in _read_status
    line = self.fp.readline()
  File "/webworks/wiki/lib/python2.5/socket.py", line 331, in readline
    data = recv(1)
KeyboardInterrupt

CherryPy Server:

This traceback occurs after a timeout of 30 seconds.

connect: (localhost, 8080)
connect fail: ('localhost', 8080)
connect: (localhost, 8080)
send: 'POST /?action=xmlrpc2 HTTP/1.0\r\nHost: localhost:8080\r\nUser-Agent: xmlrpclib.py/1.0.1 (by www.pythonware.com)\r\nContent-Type: text/xml\r\nContent-Length: 160\r\n\r\n'
send: "<?xml version='1.0'?>\n<methodCall>\n<methodName>getPage</methodName>\n<params>\n<param>\n<value><string>FrontPage</string></value>\n</param>\n</params>\n</methodCall>\n"
reply: 'HTTP/1.1 200 OK\r\n'
header: Content-Type: text/xml; charset=utf-8
header: Content-Length: 678
header: Date: Fri, 06 Jun 2008 18:58:19 GMT
header: Server: CherryPy/3.0.3
body: '<?xml version=\'1.0\'?>\n<methodResponse>\n<fault>\n<value><struct>\n<member>\n<name>faultCode</name>\n<value><int>1</int></value>\n</member>\n<member>\n<name>faultString</name>\n<value><string>&lt;class \'socket.timeout\'&gt;: timed out\n  File "/webworks/wiki/lib/python2.5/site-packages/MoinMoin/xmlrpc/__init__.py", line 122, in process\n    data = self.request.read()\n\n  File "/webworks/wiki/lib/python2.5/site-packages/MoinMoin/request/request_wsgi.py", line 49, in read\n    read_data = self.stdin.read(4000)\n\n  File "/webworks/wiki/lib/python2.5/socket.py", line 309, in read\n    data = self._sock.recv(recv_size)\n</string></value>\n</member>\n</struct></value>\n</fault>\n</methodResponse>\n'
Traceback (most recent call last):
  File "wsgi_debug.py", line 8, in <module>
    result = server.getPage("FrontPage")
  File "/webworks/wiki/lib/python2.5/xmlrpclib.py", line 1147, in __call__
    return self.__send(self.__name, args)
  File "/webworks/wiki/lib/python2.5/xmlrpclib.py", line 1437, in __request
    verbose=self.__verbose
  File "/webworks/wiki/lib/python2.5/xmlrpclib.py", line 1201, in request
    return self._parse_response(h.getfile(), sock)
  File "/webworks/wiki/lib/python2.5/xmlrpclib.py", line 1340, in _parse_response
    return u.close()
  File "/webworks/wiki/lib/python2.5/xmlrpclib.py", line 787, in close
    raise Fault(**self._stack[0])
xmlrpclib.Fault: <Fault 1: '<class \'socket.timeout\'>: timed out\n  File "/webworks/wiki/lib/python2.5/site-packages/MoinMoin/xmlrpc/__init__.py", line 122, in process\n    data = self.request.read()\n\n  File "/webworks/wiki/lib/python2.5/site-packages/MoinMoin/request/request_wsgi.py", line 49, in read\n    read_data = self.stdin.read(4000)\n\n  File "/webworks/wiki/lib/python2.5/socket.py", line 309, in read\n    data = self._sock.recv(recv_size)\n'>

Workaround

Run MoinMoin in standalone server mode to avoid having to build/configure Apache.

Discussion

Maybe try out a newer Python Version? MoinMoin needs Python 2.3 or higher (we recommend using Python 2.4.x or 2.5.x if possible).

Possible generic code changes for all Request.read() methods per ThomasWaldmann:

   1     def read(self, n=None):
   2         data = []
   3 
   4         # Read length provided?
   5         if n is None:
   6             # Try content length
   7             try:
   8                 n = int(self.headers.get('content-length'))
   9             except (TypeError, ValueError):
  10                 pass
  11 
  12         # Still no read length provided?
  13         if n is None:
  14             # We can't do that, because wsgi 1.0 requires n:
  15             #return self.stdin.read()
  16             # Thus, if we have no n, we have to simulate the usual behaviour (or
  17             # it won't work e.g. with mod_wsgi 1.3 and maybe other wsgi 1.0 servers).
  18             # Note: just requesting a extremely large amount (expecting it to never
  19             # be reached, but still all data returned) also does not work (mod_wsgi
  20             # 1.3 gives a MemoryError when doing that):
  21             while True:
  22                 read_data = self.stdin.read(4000)
  23                 if not read_data:
  24                     break
  25                 data.append(read_data)
  26         else:
  27             n_remaining = n
  28             while n_remaining > 0:
  29                 if (n_remaining > 4000):
  30                     n_chunk = 4000
  31                     n_remaining -= n_chunk
  32                 else:
  33                     n_chunk = n_remaining
  34                     n_remaining = 0
  35                 read_data = self.stdin.read(n_chunk)
  36                 if not read_data:
  37                     break;
  38                 data.append(read_data)
  39 
  40         return ''.join(data)

Plan

Priority:
Assigned to:
Status: fixed by http://hg.moinmo.in/moin/1.6/rev/8adefd81aac5 and http://hg.moinmo.in/moin/1.7/rev/fee546fba271

CategoryMoinMoinBugFixed

MoinMoin: MoinMoinBugs/XmlRpcFailsWithWSGI (last edited 2008-06-06 21:25:45 by ThomasWaldmann)