nova-api-osapi pod needs to mount /var/lib/nova/keys

with ocata version of nova kolla image, nova-api-osapi shows below error logs.

2017-10-23 05:14:50.284 44 ERROR nova File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/nova/api/openstack/__init__.py", line 243, in __init__
2017-10-23 05:14:50.284 44 ERROR nova self._register_resources_check_inherits(mapper)
2017-10-23 05:14:50.284 44 ERROR nova File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/nova/api/openstack/__init__.py", line 259, in _register_resources_check_inherits
2017-10-23 05:14:50.284 44 ERROR nova for resource in ext.obj.get_resources():
2017-10-23 05:14:50.284 44 ERROR nova File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/nova/api/openstack/compute/cloudpipe.py", line 187, in get_resources
2017-10-23 05:14:50.284 44 ERROR nova CloudpipeController())]
2017-10-23 05:14:50.284 44 ERROR nova File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/nova/api/openstack/compute/cloudpipe.py", line 48, in __init__
2017-10-23 05:14:50.284 44 ERROR nova self.setup()
2017-10-23 05:14:50.284 44 ERROR nova File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/nova/api/openstack/compute/cloudpipe.py", line 55, in setup
2017-10-23 05:14:50.284 44 ERROR nova fileutils.ensure_tree(CONF.crypto.keys_path)
2017-10-23 05:14:50.284 44 ERROR nova File "/var/lib/kolla/venv/local/lib/python2.7/site-packages/oslo_utils/fileutils.py", line 40, in ensure_tree
2017-10-23 05:14:50.284 44 ERROR nova os.makedirs(path, mode)
2017-10-23 05:14:50.284 44 ERROR nova File "/var/lib/kolla/venv/lib/python2.7/os.py", line 157, in makedirs
2017-10-23 05:14:50.284 44 ERROR nova mkdir(name, mode)
2017-10-23 05:14:50.284 44 ERROR nova OSError: [Errno 13] Permission denied: '/var/lib/nova/keys'
2017-10-23 05:14:50.284 44 ERROR nova

so it needs to mount /var/lib/nova directory in nova-api-osapi pod.