Links are also highly appreciated.

My ES section looks as follow:

es:
    bufferSize: 20MB
    generateID: true
    host: fluentbit-es-es-http.fluent.svc
    index: my_new_index
    port: 9200
    replaceDots: false
    suppressTypeName: "On"
    timeKey: '@timestamp'
    type: create

I suppose

type: create

and

index: <name>

influences on this. But such config creates just plain ES index and not datastream. Does ES datastream need to be created before sending anything there?

Well I see that Index Template for datastream needs to be created before sending something inside of it (otherwise just plain index will be created). But as I can see there is no alternative for

index

option like

LogstashPrefixKey: kubernetes['labels']['<http://app.kubernetes.io/name|app.kubernetes.io/name>']

so right now only one datastream is supported with such scheme.

https://github.com/fluent/fluent-operator/blob/master/manifests/logging-stack/output-elasticsearch.yaml https://github.com/fluent/fluent-operator/blob/master/apis/fluentbit/v1alpha2/plugins/output/elasticsearch_types.go https://github.com/fluent/fluent-bit/issues/2664