Public bug reported:
In a component of MAAS we're using python-bson to dump out structures
containing binary data. Everything works fine in development, but breaks
in production under Apache.
In Python 2.x (we're using 2.7) it's necessary to wrap str/bytes objects
in bson.binary.Binary; the encoder then does an isinstance check and
encodes these objects as binary data - or "\x05" e_name binary, from the
spec. However, under Apache our binary data is being encoded as string
data - or "\x02" e_name string, from the spec. When decoding this
becomes a unicode object, which chokes the next part of the MAAS's
processing.
I think this is due to the C extension module. Apache and/or mod_wsgi
does some weird things with Python contexts (I don't know much about
this, just enough to know it can be a problem), and I suspect the
PyObject_IsInstance(value, state->Binary) condition in
bson/_cbsonmodule.c is failing because state->Binary is referencing a
different Binary type than MAAS's code is.
The following are the mod_wsgi directives we're using in Apache:
{{{
WSGIDaemonProcess maas user=maas group=maas processes=2 threads=1
display-name=%{GROUP}
# Without this, defining a tag as a malformed xpath expression will hang
# the region controller.
# See
https://techknowhow.library.emory.edu/blogs/branker/2010/07/30/django-lxml-wsgi-and-python-sub-interpreter-magic
WSGIApplicationGroup %{GLOBAL}
WSGIScriptAlias /MAAS /usr/share/maas/wsgi.py
# Preload application when process starts. This will allow publishing
# the MAAS server existence over Avahi.
WSGIImportScript /usr/share/maas/wsgi.py process-group=maas
application-group=maas
WSGIPassAuthorization On
<Directory /usr/share/maas/>
WSGIProcessGroup maas
</Directory>
}}}
$ apt-cache policy apache2 libapache2-mod-wsgi python-bson python-bson-ext
apache2:
Installed: 2.4.6-2ubuntu2
Candidate: 2.4.6-2ubuntu2
Version table:
*** 2.4.6-2ubuntu2 0
500 http://gb.archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages
100 /var/lib/dpkg/status
libapache2-mod-wsgi:
Installed: 3.4-4
Candidate: 3.4-4
Version table:
*** 3.4-4 0
500 http://gb.archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages
100 /var/lib/dpkg/status
python-bson:
Installed: 2.6-1
Candidate: 2.6-1
Version table:
*** 2.6-1 0
500 http://gb.archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages
100 /var/lib/dpkg/status
python-bson-ext:
Installed: 2.6-1
Candidate: 2.6-1
Version table:
*** 2.6-1 0
500 http://gb.archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages
100 /var/lib/dpkg/status
** Affects: maas
Importance: Critical
Status: Triaged
** Affects: maas (Ubuntu)
Importance: Undecided
Status: New
** Affects: pymongo (Ubuntu)
Importance: Undecided
Status: New
** Also affects: maas (Ubuntu)
Importance: Undecided
Status: New
** Also affects: maas
Importance: Undecided
Status: New
** Changed in: maas
Status: New => Triaged
** Changed in: maas
Importance: Undecided => Critical
--
You received this bug notification because you are a member of Ubuntu
Server Team, which is subscribed to pymongo in Ubuntu.
https://bugs.launchpad.net/bugs/1237615
Title:
python-bson-ext does not encode binary in Apache with mod_wsgi
To manage notifications about this bug go to:
https://bugs.launchpad.net/maas/+bug/1237615/+subscriptions
--
Ubuntu-server-bugs mailing list
Ubuntu-server-bugs@lists.ubuntu.com
Modify settings or unsubscribe at:
https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
