Elasticsearch 8 should emit structured logs with ECS 8

[yaauie]

ECS 8 is set to be released along-side Elastic Stack 8. I would expect to see an 8.x version in the structured logs emitted by Elasticsearch 8 snapshots, but I am still seeing "ecs.version": "1.2.0":

{"@timestamp":"2022-01-11T22:02:37.530Z", "log.level": "INFO", "message":"version[8.1.0-SNAPSHOT], pid[9], build[default/docker/0ca3db6d66a483f6377ca6eb4d0142c895cf693d/2022-01-10T16:05:39.811971724Z], OS[Linux/5.11.0-1023-gcp/amd64], JVM[Eclipse Adoptium/OpenJDK 64-Bit Server VM/17.0.1/17.0.1+12]", "ecs.version": "1.2.0","service.name":"ES_ECS","event.dataset":"elasticsearch.server","process.thread.name":"main","log.logger":"org.elasticsearch.node.Node","elasticsearch.node.name":"25ec142c5879","elasticsearch.cluster.name":"docker-cluster"}

I suspect this is because Elasticsearch relies on elastic/ecs-logging-java, which hard-codes 1.2.0 in its latest release. The scope of changes from 1.last to 8.0 is small, and is gathered in elastic/ecs#839

[elasticmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)

[pgomulka]

@yaauie as you mentioned. We rely on ecs-logging-java which is using 1.2.0 as ecs.version. The reason is that the ecs-logging-java do not use fields added after 1.2.0, so should only indicated the "minimum version supported"
see the discussion on this here elastic/ecs-logging#44
I will close the issue for now