Support non-string labels

APM has support for that but in ECS, labels are mapped as keyword

@pgomulka would you need non-string MapMessage values for Elasticsearch?

[felixbarny]

That works with this change: https://github.com/elastic/java-ecs-logging/pull/30

MapMessage supports rendering the message as JSON which EcsLayout is now delegating the rendering to. So you could either use MapMessage, which would render the plain text message slightly differently (key="value"). Or you could create your own class which implements MultiformatMessage (or better MultiFormatStringBuilderFormattable) and which supports a JSON and a plain-text format.

[pgomulka]

there are some fields that are non string but I format them as strings anyway so that is fine

{"type": "index_indexing_slowlog", "timestamp": "2019-06-24T15:01:11,415-04:00", "level": "WARN", "component": "i.i.s.index", "cluster.name": "esprod", "node.name": "esprod0", "message": "[foo/6cpavWDYRO6pyxezB0LepA]", "took": "3ms", "took_millis": "3", "doc_type": "t", "id": "1", "routing": "", "source": "{\"foo\":\"bar\"}", "cluster.uuid": "b28RGuVmRDimbAkNTVbacg", "node.id": "erxPlzmKQOGUdrDxGrww_g"  }
{"type": "index_indexing_slowlog", "timestamp": "2019-07-09T04:48:28,203-04:00", "level": "WARN", "component": "i.i.s.index", "cluster.name": "es1", "node.name": "es1_1", "message": "[foo/DubP3paOQJCtD1EkUmqxpw]", "took": "2.3ms", "took_millis": "2", "doc_type": "_doc", "id": "1", "source": "{\"foo\":\"bar\"}", "cluster.uuid": "xOp8Gs9TTa-SoSWcs6NZHg", "node.id": "BgSzU7SUTgeRYqzbiyf1sA"  }