MemcachedStringEncodingError in pool manager with memcached

[Paul Glass]

Reproduction: Configure the pool manager to use memcached, then create a zone. You should see an error like this: http://paste.openstack.org/show/182147/

Excerpt:

  File "/root/designate/.venv/local/lib/python2.7/site-packages/memcache.py", line 1050, in check_key
     "Keys must be str()'s, not unicode. Convert your unicode "
MemcachedStringEncodingError: Keys must be str()'s, not unicode. Convert your unicode strings using mystring.encode(charset)!

This seems to cause zone creates to fail (remain in PENDING forever).

Notes: This was on commit 13fd93bc495d71152f8e6e0559788e30ef3723ec.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/159870

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/159870
Committed: https://git.openstack.org/cgit/openstack/designate/commit/?id=8d33b4bd2cc143774d1838872d5ed11eb8de8de7
Submitter: Jenkins
Branch: master

commit 8d33b4bd2cc143774d1838872d5ed11eb8de8de7
Author: Eric Larson <email address hidden>
Date: Fri Feb 27 08:45:03 2015 -0600

    Ensure pool_manager cache keys are strings

    Messages coming from rabbitmq are unicode objects. We need to explicitly
    convert any resulting bytes to a string when performing interpolations
    if the result is a memcached key.

    Change-Id: Idf37ef8e42e93d92af04268e68ef620bca39e04c
    Closes-Bug: 1425751