I installed Elasticsearch this way:

helm repo add bitnami https://charts.bitnami.com/bitnami 
helm repo update
kubectl create ns elk
helm upgrade --install elasticsearch --namespace=elk --set master.replicaCount=3,ingest.enabled=false,data.replicaCount=4,master.masterOnly=false,coordinating.replicaCount=0 bitnami/elasticsearch
kubectl port-forward --namespace elk svc/elasticsearch 9200:9200

The pods are running:

kubectl get po -n elk
NAME                     READY   STATUS    RESTARTS   AGE
elasticsearch-data-3     1/1     Running   0          13m
elasticsearch-data-2     1/1     Running   0          13m
elasticsearch-master-2   1/1     Running   0          13m
elasticsearch-data-1     1/1     Running   0          11m
elasticsearch-master-1   1/1     Running   0          11m
elasticsearch-data-0     1/1     Running   0          9m37s
elasticsearch-master-0   1/1     Running   0          9m34s

I can confirm the Elasticsearch data via:

curl http://127.0.0.1:9200

But in Grafana, how to set the connection URL?

It happened:

Unable to connect with Elasticsearch. Please check the server logs for more details.

Some logs:

error” error=”[plugin.downstreamError] client: failed to call resources: Get “http://localhost:9200″: dial tcp 127.0.0.1:9200: connect: connection refused” remote_addr=127.0.0.1 traceID=