string io errors in unit test

[Lianhao Lu]

Since https://review.openstack.org/#/c/71688/, we saw stringIO errors in gate logs,

2014-02-06 23:52:52.448 | Error in atexit._run_exitfuncs:
2014-02-06 23:52:52.448 | Traceback (most recent call last):
2014-02-06 23:52:52.449 | File "/usr/lib64/python2.6/atexit.py", line 24, in _run_exitfuncs
2014-02-06 23:52:52.449 | func(*targs, **kargs)
2014-02-06 23:52:52.449 | File "/usr/lib64/python2.6/logging/__init__.py", line 1516, in shutdown
2014-02-06 23:52:52.450 | h.flush()
2014-02-06 23:52:52.450 | File "/usr/lib64/python2.6/logging/__init__.py", line 762, in flush
2014-02-06 23:52:52.450 | self.stream.flush()
2014-02-06 23:52:52.451 | File "/usr/lib64/python2.6/StringIO.py", line 256, in flush
2014-02-06 23:52:52.453 | _complain_ifclosed(self.closed)
2014-02-06 23:52:52.453 | File "/usr/lib64/python2.6/StringIO.py", line 40, in _complain_ifclosed
2014-02-06 23:52:52.453 | raise ValueError, "I/O operation on closed file"
2014-02-06 23:52:52.454 | ValueError: I/O operation on closed file
2014-02-06 23:52:52.454 | Error in sys.exitfunc:

Recently, it was mixed with another unknown problem which resulted high gate failure rate (which is tracked by another bug https://bugs.launchpad.net/ceilometer/+bug/1328679).

This bug is to track the root cause of this stringIO error.

[gordon chung (chungg)]

ER query patch here: https://review.openstack.org/#/c/100405/

[gordon chung (chungg)]

ignore above comment

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/101231

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/101231
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=c0702b298a8614a713ca392d0fcdb9bdaae9faac
Submitter: Jenkins
Branch: master

commit c0702b298a8614a713ca392d0fcdb9bdaae9faac
Author: Gordon Chung <email address hidden>
Date: Thu Jun 19 11:04:50 2014 -0400

    fix StringIO errors in unit test

    alarm tests are throwing StringIO failures as it's being closed to soon.
    change the way we capture logging.

    Change-Id: Ifd956b8fe144219d029f8afb369ec25d13177078
    Closes-Bug: #1329692

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/icehouse
Review: https://review.openstack.org/113642

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/113642
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=4e2c1cd3086cad8c408ac3d5a4889b79671deff5
Submitter: Jenkins
Branch: stable/icehouse

commit 4e2c1cd3086cad8c408ac3d5a4889b79671deff5
Author: Gordon Chung <email address hidden>
Date: Thu Jun 19 11:04:50 2014 -0400

    fix StringIO errors in unit test

    alarm tests are throwing StringIO failures as it's being closed to soon.
    change the way we capture logging.

    Change-Id: Ifd956b8fe144219d029f8afb369ec25d13177078
    Closes-Bug: #1329692
    (cherry picked from commit c0702b298a8614a713ca392d0fcdb9bdaae9faac)