Merge lp:~jconti/oneconf/closeable-cache into lp:oneconf

[Jason Conti]

Close the apt cache once we are finished using it, so we do not leak file descriptors.

=== modified file 'oneconf/distributor/Ubuntu.py'
--- oneconf/distributor/Ubuntu.py	2011-10-19 16:20:18 +0000
+++ oneconf/distributor/Ubuntu.py	2013-08-27 21:05:06 +0000
@@ -35,13 +35,14 @@
         '''
         
         LOG.debug ('Compute package list for current host')
-        apt_cache = apt.Cache()
 
         # get list of all apps installed
         installed_packages = {}
-        for pkg in apt_cache:
-            if pkg.is_installed:
-                installed_packages[pkg.name] = {"auto": pkg.is_auto_installed}
+
+        with apt.Cache() as apt_cache:
+            for pkg in apt_cache:
+                if pkg.is_installed:
+                    installed_packages[pkg.name] = {"auto": pkg.is_auto_installed}
 
         return installed_packages