ensure that the docs explicitly caution to keep the hash path suffix secret

[John Dickinson]

Question #156307 on OpenStack Object Storage (swift) changed:
https://answers.launchpad.net/swift/+question/156307

Rostik Slipetskyy posted a new comment:
we caution deployers to keep it secret in the docs (...) The
hash_path_suffix should be kept as secret as an /etc/shadow file or the
secret key of a key pair.

I just rechecked the Administrator manual
(http://docs.openstack.org/cactus/openstack-object-storage/admin/os-
objectstorage-adminguide-cactus.pdf), and what I found with respect to
swift_hash_path_suffix was:

"# random unique string that can never change (DO NOT LOSE)"

Maybe I have missed other places where the necessity to keep
swift_hash_path_suffix secret were mentioned, but it might make sense to
indicate it in Admin manual and also at etc/swift.conf-sample from the
distribution. Just as a precaution measure.

[Anne Gentle (annegentle)]

I've changed the docs in openstack-manuals and you can also assign it to me to fix in Swift as well.

[Samuel Merritt (torgomatic)]

Commit a2ac5ef updated the text in swift.conf-sample to say:

# swift_hash_path_suffix is used as part of the hashing algorithm
# when determining data placement in the cluster. This value should
# remain secret and MUST NOT change once a cluster has been deployed.

Is this sufficient?

[Samuel Merritt (torgomatic)]

The fix has been deemed sufficient.