When the ceph.conf is not in a well-known location, it is typical
for a custom ceph.keyring to be required as well. Currently, the
create-external-cluster-resources.py only tries to load the keyring
from well-known paths, and fails.
This commit adds a new optional argument `--keyring` to help in this
situation. When specified, create-external-cluster-resources.py will
attempt to use this as the keyring to authenticate with Ceph.
Signed-off-by: Angelos Kolaitis <neoaggelos@gmail.com>
(cherry picked from commit c021256e96)