compute_signature method failed if metadata keys contain unicode

[Ilya Tyaptin]

Unlike fixed sample keys as counter_name and counter_volume, metadata keys may contain a unicode in keys. ceilometer.publisher_utils.compute_signature can't calculate signature of unicode symbols and crashes. So we should encode keys when signature is computed.

Traceback (most recent call last):
  File "ceilometer/tests/base.py", line 99, in skip_if_not_implemented
    return func(*args, **kwargs)
  File "ceilometer/tests/api/v2/test_list_meters_scenarios.py", line 182, in setUp
    self.CONF.publisher.metering_secret)
  File "ceilometer/publisher/utils.py", line 122, in meter_message_from_counter
    msg['message_signature'] = compute_signature(msg, secret)
  File "ceilometer/publisher/utils.py", line 51, in compute_signature
    digest_maker.update(name)
  File "/usr/lib/python2.7/hmac.py", line 83, in update
    self.inner.update(msg)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 30-31: ordinal not in range(128)
}}}

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/133707

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/133707
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=05276690525d76e18769712bc66d0cd535b11f18
Submitter: Jenkins
Branch: master

commit 05276690525d76e18769712bc66d0cd535b11f18
Author: Ilya Tyaptin <email address hidden>
Date: Tue Nov 11 17:17:04 2014 +0400

    Add encoding to keys in compute_signature

    Unlike fixed sample keys as counter_name and counter_volume,
    metadata keys may contain unicode characters.
    ceilometer.publisher.utils.compute_signature can't calculate
    signature of unicode symbols and crashes.
    In this patch encoding keys is added.

    Change-Id: I94d02ce20999510e9c6aaf33f7ee503bbb350e87
    Closes-bug: #1391517

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/juno
Review: https://review.openstack.org/137680

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/137680
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=ca52652e5a14f2332bd91b0c5a57e98af872c8db
Submitter: Jenkins
Branch: stable/juno

commit ca52652e5a14f2332bd91b0c5a57e98af872c8db
Author: Ilya Tyaptin <email address hidden>
Date: Tue Nov 11 17:17:04 2014 +0400

    Add encoding to keys in compute_signature

    Unlike fixed sample keys as counter_name and counter_volume,
    metadata keys may contain unicode characters.
    ceilometer.publisher.utils.compute_signature can't calculate
    signature of unicode symbols and crashes.
    In this patch encoding keys is added.

    Change-Id: I94d02ce20999510e9c6aaf33f7ee503bbb350e87
    Closes-bug: #1391517
    (cherry picked from commit 05276690525d76e18769712bc66d0cd535b11f18)