config-changed fails on upgrade to cs:swift-storage-249 with loop devices

[Xav Paice]

Upgrade charm to cs:swift-storage-249 (from 247). The config-changed hook failed with:

2018-11-20 04:12:43 INFO juju-log Making dir /srv/node swift:swift 755
2018-11-20 04:12:43 DEBUG config-changed Traceback (most recent call last):
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/hooks/config-changed", line 430, in <module>
2018-11-20 04:12:43 DEBUG config-changed main()
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/hooks/config-changed", line 418, in main
2018-11-20 04:12:43 DEBUG config-changed hooks.execute(sys.argv)
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/charmhelpers/core/hookenv.py", line 909, in execute
2018-11-20 04:12:43 DEBUG config-changed self._hooks[hook_name]()
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/charmhelpers/core/host.py", line 717, in wrapped_f
2018-11-20 04:12:43 DEBUG config-changed restart_functions)
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/charmhelpers/core/host.py", line 739, in restart_on_change_helper
2018-11-20 04:12:43 DEBUG config-changed r = lambda_f()
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/charmhelpers/core/host.py", line 716, in <lambda>
2018-11-20 04:12:43 DEBUG config-changed (lambda: f(*args, **kwargs)), restart_map, stopstart,
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/charmhelpers/contrib/hardening/harden.py", line 93, in _harden_inner2
2018-11-20 04:12:43 DEBUG config-changed return f(*args, **kwargs)
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/hooks/config-changed", line 236, in config_changed
2018-11-20 04:12:43 DEBUG config-changed configure_storage()
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/hooks/config-changed", line 345, in configure_storage
2018-11-20 04:12:43 DEBUG config-changed setup_storage(config('encrypt'))
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/lib/swift_storage_utils.py", line 481, in setup_storage
2018-11-20 04:12:43 DEBUG config-changed for dev in determine_block_devices():
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/lib/swift_storage_utils.py", line 294, in determine_block_devices
2018-11-20 04:12:43 DEBUG config-changed [x for x in map(ensure_block_device, bdevs) if str(x).lower() not in
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/lib/swift_storage_utils.py", line 294, in <listcomp>
2018-11-20 04:12:43 DEBUG config-changed [x for x in map(ensure_block_device, bdevs) if str(x).lower() not in
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/lib/misc_utils.py", line 70, in ensure_block_device
2018-11-20 04:12:43 DEBUG config-changed bdev = ensure_loopback_device(bdev, size)
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/charmhelpers/contrib/storage/linux/loopback.py", line 68, in ensure_loopback_device
2018-11-20 04:12:43 DEBUG config-changed for d, f in six.iteritems(loopback_devices()):
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/charmhelpers/contrib/storage/linux/loopback.py", line 40, in loopback_devices
2018-11-20 04:12:43 DEBUG config-changed check_output(cmd).splitlines() if d != '']
2018-11-20 04:12:43 DEBUG config-changed File "/var/lib/juju/agents/unit-swift-storage-z1-0/charm/charmhelpers/contrib/storage/linux/loopback.py", line 40, in <listcomp>
2018-11-20 04:12:43 DEBUG config-changed check_output(cmd).splitlines() if d != '']
2018-11-20 04:12:43 DEBUG config-changed TypeError: 'str' does not support the buffer interface
2018-11-20 04:12:43 ERROR juju.worker.uniter.operation runhook.go:129 hook "config-changed" failed: exit status 1

The block-device setting is currently '/srv/node/swift1/swift.img|500G /srv/node/swift2/swift.img|500G'.

[Alex Kavanagh (ajkavanagh)]

This is because swift-storage is now a py3 charm, but the code in charmhelpers wasn't actually upgraded to py3 code entirely.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/619009

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/619009
Committed: https://git.openstack.org/cgit/openstack/charm-swift-storage/commit/?id=25ec6c6a3dd609746d1194a07588ca954f19a333
Submitter: Zuul
Branch: master

commit 25ec6c6a3dd609746d1194a07588ca954f19a333
Author: Alex Kavanagh <email address hidden>
Date: Tue Nov 20 14:27:55 2018 +0000

    Sync c-h with loopback_devices() fix

    PY3 bug in loopback_devices caused the related bug. This patch syncs
    just the relevant file to fix the bug into charmhelpers.

    Change-Id: I5aacd16c2bd4957c49210e867dc76efa1a315ab4
    Closes-Bug: #1804128

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/18.11
Review: https://review.openstack.org/619078

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/619078
Committed: https://git.openstack.org/cgit/openstack/charm-swift-storage/commit/?id=49b53d996c9cc5dac594844091ddbaac05a6f207
Submitter: Zuul
Branch: stable/18.11

commit 49b53d996c9cc5dac594844091ddbaac05a6f207
Author: Alex Kavanagh <email address hidden>
Date: Tue Nov 20 14:27:55 2018 +0000

    Sync c-h with loopback_devices() fix

    PY3 bug in loopback_devices caused the related bug. This patch syncs
    just the relevant file to fix the bug into charmhelpers.

    Closes-Bug: #1804128
    (cherry picked from commit 25ec6c6a3dd609746d1194a07588ca954f19a333)

    Change-Id: I0fd46225f8afac9c7105232330ca54529d5b78f2