launchpad-reviewers team mailing list archive

["Jeroen T. Vermeulen" <jtv@xxxxxxxxxxxxx>]

Jeroen T. Vermeulen has proposed merging lp:~jtv/maas/bug-1064737 into lp:maas.

Commit message:
Work around lxml locking up its region controller process in production (not in a branch!) when validating a malformed xpath expression as a tag definition.

See https://techknowhow.library.emory.edu/blogs/branker/2010/07/30/django-lxml-wsgi-and-python-sub-interpreter-magic

Requested reviews:
  Launchpad code reviewers (launchpad-reviewers)
Related bugs:
  Bug #1064737 in MAAS: "Adding a new tag with empty string as the definition parameter causes maas-cli to hang"
  https://bugs.launchpad.net/maas/+bug/1064737

For more details, see:
https://code.launchpad.net/~jtv/maas/bug-1064737/+merge/128891

Sanity-checked with Raphael; he can't think of any problems that this might cause.  Martin notes that "we probably want to use the daemon configuration for mod_wsgi longer term."


Jeroen
-- 
https://code.launchpad.net/~jtv/maas/bug-1064737/+merge/128891
Your team Launchpad code reviewers is requested to review the proposed merge of lp:~jtv/maas/bug-1064737 into lp:maas.

=== modified file 'contrib/maas-http.conf'
--- contrib/maas-http.conf	2012-10-02 19:08:05 +0000
+++ contrib/maas-http.conf	2012-10-10 09:38:22 +0000
@@ -1,4 +1,10 @@
 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.