maas django app won't start "ImportError: No module named apt_pkg"

[Chris J Arges]

Installed MAAS fresh into an LXC container using stable PPA:
https://launchpad.net/~maas-maintainers/+archive/ubuntu/stable

sudo apt-get install maas maas-dhcp maas-dns

Then I check http://<host>/MAAS and get a 500 error:

[Tue Apr 21 21:43:16.219698 2015] [:error] [pid 11958:tid 140276131022592] [remote 10.38.36.4:1205] ImportError: No module named apt_pkg
[Tue Apr 21 21:43:18.218545 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] mod_wsgi (pid=11959): Exception occurred processing WSGI script '/usr/share/maas/wsgi.py'.
[Tue Apr 21 21:43:18.218587 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] Traceback (most recent call last):
[Tue Apr 21 21:43:18.218612 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/core/handlers/wsgi.py", line 187, in __call__
[Tue Apr 21 21:43:18.218648 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] self.load_middleware()
[Tue Apr 21 21:43:18.218663 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/core/handlers/base.py", line 47, in load_middleware
[Tue Apr 21 21:43:18.218685 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] mw_instance = mw_class()
[Tue Apr 21 21:43:18.218698 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/maasserver/middleware.py", line 111, in __init__
[Tue Apr 21 21:43:18.218718 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] reverse('login'),
[Tue Apr 21 21:43:18.218731 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/core/urlresolvers.py", line 536, in reverse
[Tue Apr 21 21:43:18.218751 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] return iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs))
[Tue Apr 21 21:43:18.218775 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/core/urlresolvers.py", line 403, in _reverse_with_prefix
[Tue Apr 21 21:43:18.218798 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] self._populate()
[Tue Apr 21 21:43:18.218811 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/core/urlresolvers.py", line 267, in _populate
[Tue Apr 21 21:43:18.218831 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] for pattern in reversed(self.url_patterns):
[Tue Apr 21 21:43:18.218844 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/core/urlresolvers.py", line 365, in url_patterns
[Tue Apr 21 21:43:18.218887 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
[Tue Apr 21 21:43:18.218910 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/core/urlresolvers.py", line 360, in urlconf_module
[Tue Apr 21 21:43:18.218935 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] self._urlconf_module = import_module(self.urlconf_name)
[Tue Apr 21 21:43:18.218949 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/utils/importlib.py", line 40, in import_module
[Tue Apr 21 21:43:18.218970 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] __import__(name)
[Tue Apr 21 21:43:18.218983 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/share/maas/maas/urls.py", line 28, in <module>
[Tue Apr 21 21:43:18.219003 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] url(r'^', include('maasserver.urls')),
[Tue Apr 21 21:43:18.219016 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/conf/urls/__init__.py", line 26, in include
[Tue Apr 21 21:43:18.219037 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] urlconf_module = import_module(urlconf_module)
[Tue Apr 21 21:43:18.219049 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/utils/importlib.py", line 40, in import_module
[Tue Apr 21 21:43:18.219069 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] __import__(name)
[Tue Apr 21 21:43:18.219081 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/maasserver/urls.py", line 329, in <module>
[Tue Apr 21 21:43:18.219101 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] (r'^api/1\\.0/', include('maasserver.urls_api'))
[Tue Apr 21 21:43:18.219114 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/conf/urls/__init__.py", line 26, in include
[Tue Apr 21 21:43:18.219133 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] urlconf_module = import_module(urlconf_module)
[Tue Apr 21 21:43:18.219145 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/django/utils/importlib.py", line 40, in import_module
[Tue Apr 21 21:43:18.219164 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] __import__(name)
[Tue Apr 21 21:43:18.219177 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/maasserver/urls_api.py", line 101, in <module>
[Tue Apr 21 21:43:18.219197 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] from maasserver.api.version import VersionHandler
[Tue Apr 21 21:43:18.219218 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/maasserver/api/version.py", line 23, in <module>
[Tue Apr 21 21:43:18.219241 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] from maasserver.utils.version import get_maas_version_subversion
[Tue Apr 21 21:43:18.219254 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] File "/usr/lib/python2.7/dist-packages/maasserver/utils/version.py", line 21, in <module>
[Tue Apr 21 21:43:18.219274 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] import apt_pkg
[Tue Apr 21 21:43:18.219296 2015] [:error] [pid 11959:tid 140276131022592] [remote 10.38.36.4:1205] ImportError: No module named apt_pkg

I can then install python-apt and fix this issue.

[Mike Pontillo (mpontillo)]

I thought we recently fixed this. Either the version under test doesn't have the fix yet, or we missed the fix for some subset of MAAS packages. I will check tomorrow.

[Mike Pontillo (mpontillo)]

This should have been fixed with the following commit to the packaging branch:

https://code.launchpad.net/~mpontillo/maas/packaging-python-apt-fix/+merge/255265

[Adam Conrad (adconrad)]

Hello Chris, or anyone else affected,

Accepted maas into vivid-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/maas/1.7.3+bzr3363-0ubuntu2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Andres Rodriguez (andreserl)]

This has been verified and proven to work.

[Launchpad Janitor (janitor)]

This bug was fixed in the package maas - 1.7.3+bzr3363-0ubuntu2

---------------
maas (1.7.3+bzr3363-0ubuntu2) vivid; urgency=medium

  * Use python-django16 instead of python-django ( 1.7). MAAS does not
    support django 1.7 due to having a new migration system. (LP: #1447573)
  * Adding systemd units and packaging support. (LP: #1423613)
  * debian/control: Add missing dependency on python-apt. (LP: #1446878)
 -- Andres Rodriguez <email address hidden> Wed, 22 Apr 2015 12:10:50 -0400

[Adam Conrad (adconrad)]

The verification of the Stable Release Update for maas has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Nick (nyt1066)]

Are there any plans to update this package in https://launchpad.net/~maas-maintainers/+archive/ubuntu/stable for 14.04?