elastic roles privileges

To write/ingest indices,  user must have role with:
- cluster: "manage_index_templates", "monitor", "manage_ilm"
- indices privileges: "write","create","delete","create_index","manage","manage_ilm"



To read the indices, minumum priveleges:
- "read","view_index_metadata"

ref: https://www.elastic.co/guide/en/logstash/current/ls-security.html