Merge lp:~kissiel/checkbox/fix-1569575-root-leftovers-crash into lp:checkbox

[Maciej Kisielewski]

This patch handles PermissionError exceptions coming from TemporaryDirectory.

Consider a job, that is run as root that runs cp somedir .

When the temp cwd context manager is left, the cleanup is run as the user
running plainbox, not root. This caused plainbox to crashed.

This patch makes plainbox display a warning and proceed.

9ca20ea plainbox:ctrl: catch tempcwd errors and print warning

[Sylvain Pineau (sylvain-pineau)]

I'm ok with the patch, doing the cleanup as root from python is 1. not easy and 2. if it was possible from plainbox it would open the door to all sort of arbitrary commands being run as root. So +1 to log a warning and proceed. thanks

review: Approve

[Maciej Kisielewski (kissiel)]

\o/ Let's land it then.

=== modified file 'plainbox/plainbox/impl/ctrl.py'
--- plainbox/plainbox/impl/ctrl.py	2015-09-25 08:39:43 +0000
+++ plainbox/plainbox/impl/ctrl.py	2016-04-27 04:01:05 +0000
@@ -606,15 +606,20 @@
         # Create a nest for all the private executables needed for execution
         prefix = 'cwd-'
         suffix = '.{}'.format(job.checksum)
-        with tempfile.TemporaryDirectory(suffix, prefix) as cwd_dir:
-            logger.debug(
-                _("Job temporary current working directory: %s"), cwd_dir)
-            try:
-                yield cwd_dir
-            finally:
-                leftovers = self._find_leftovers(cwd_dir)
-                if leftovers:
-                    self.on_leftover_files(job, config, cwd_dir, leftovers)
+        try:
+            with tempfile.TemporaryDirectory(suffix, prefix) as cwd_dir:
+                logger.debug(
+                    _("Job temporary current working directory: %s"), cwd_dir)
+                try:
+                    yield cwd_dir
+                finally:
+                    leftovers = self._find_leftovers(cwd_dir)
+                    if leftovers:
+                        self.on_leftover_files(job, config, cwd_dir, leftovers)
+        except PermissionError as exc:
+            logger.warning(
+                _("There was a problem with temporary cwd %s, %s"),
+                cwd_dir, exc)
 
     def _find_leftovers(self, cwd_dir):
         """