Description of problem:
For openshift_hosted_logging&openshift_hosted_metrics will be deprecated. I want to fresh installl OCP and enable logging using none openshift_hosted_logging variables. but the installer failed in role openshift_storage_nfs.


Version-Release number of the following components:
openshift-ansible:master


How reproducible:
always

Steps to Reproduce:
1. set logging deploy variable inventory and use nfs hosts
# Logging
openshift_logging_install_logging=true
openshift_logging_kibana_hostname=kibana.example.com
openshift_logging_kibana_ops_hostname=kibana-ops.example.com
public_master_url=https://example1:8443
openshift_logging_namespace=logging
openshift_logging_fluentd_use_journal=true
openshift_logging_use_mux=true
openshift_logging_use_mux_client=true
openshift_logging_es_pvc_prefix=logging-es
#openshift_logging_es_pvc_size=10G
openshift_logging_purge_logging=true
openshift_logging_es_pvc_dynamic=True
openshift_logging_kibana_memory_limit=1Gi
openshift_logging_kibana_ops_memory_limit=1Gi
openshift_logging_es_memory_limit=1Gi
openshift_logging_es_ops_memory_limit=1Gi


2. install openshift 
 ansible-playbook /root/openshift-ansible/playbooks/byo/config.yml 

Actual results:
TASK [openshift_storage_nfs : Ensure exports directory exists] ****************************************************************************************************************************************************
fatal: [openshift-225.example.com]: FAILED! => {
    "failed": true
}

MSG:

the field 'args' has an invalid value, which appears to include a variable that is undefined. The error was: 'dict object' has no attribute 'storage'

The error appears to have been in '/root/openshift-ansible/roles/openshift_storage_nfs/tasks/main.yml': line 20, column 3, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:


- name: Ensure exports directory exists
  ^ here

    to retry, use: --limit @/root/openshift-ansible/playbooks/byo/config.retry

PLAY RECAP ********************************************************************************************************************************************************************************************************
localhost                  : ok=12   changed=0    unreachable=0    failed=0   
openshift-208.example.com : ok=49   changed=5    unreachable=0    failed=0   
openshift-225.example.com : ok=115  changed=44   unreachable=0    failed=1   



Failure summary:


  1. Hosts:    openshift-225.example.com
     Play:     Configure nfs
     Task:     Ensure exports directory exists
     Message:  the field 'args' has an invalid value, which appears to include a variable that is undefined. The error was: 'dict object' has no attribute 'storage'
               
               The error appears to have been in '/root/openshift-ansible/roles/openshift_storage_nfs/tasks/main.yml': line 20, column 3, but may
               be elsewhere in the file depending on the exact syntax problem.
               
               The offending line appears to be:
               
               
               - name: Ensure exports directory exists
                 ^ here


Expected results:
The install completed, the logging are deployed.

Additional info: