This is a known issue in the current beta1 release, unfortunately. The native realm is disabled by the operator. You can reenable it with this cluster definition (this example is based on the cluster we use in the quickstart guide, you have to adapt it to your needs)
apiVersion: elasticsearch.k8s.elastic.co/v1beta1
kind: Elasticsearch
metadata:
name: quickstart
spec:
version: 7.4.0
nodeSets:
- name: default
count: 1
config:
node.master: true
node.data: true
node.ingest: true
node.store.allow_mmap: false
xpack.security.authc.realms:
native:
native1:
order: 1
The important part is:
xpack.security.authc.realms:
native:
native1:
order: 1
which enables the native realm and should fix your issue.
We are tracking this bug in this Github issue:
This will be fixed in the next release.