Description of problem:
There is not easy way with via the deployer to set Supplemental Groups or fsGroup. These would need to be manually added after a deploy. In which case the deploy would fail because it does not have permissions to write to the PV that is attached.
Closing as not a bug, the following can be set in ansible:
Which set this value in es templates
Note this variable officially applies to using ansible with 3.5 deployments only. You can try to use the same role with 3.4, but the official supported option is through the deployer or the associated 3.4 openshift_hosted_logging role. In 3.4, you can set the STORAGE_GROUPS env var and it will be substituted in the template for ElasticSearch
The deployer var for reference: https://github.com/openshift/origin-aggregated-logging/blob/v1.4.1/deployer/templates/es.yaml#L48