[Metricbeat] Istio metricset pilot fails to index event

[blakerouse]

During the 7.7.0 testing I hit an issue with isto.mixer. It is failing to index the event into elasticsearch.

• Version: 7.7.0 BC4
• Operating System: Ubuntu 19.10
• Kubernetes Version: 1.18 (microk8s)
• Istio Version: 1.3.4

2020-04-06T22:37:27.249-0400 WARN [elasticsearch] elasticsearch/client.go:384 Cannot index event publisher.Event{Content:beat.Event{Timestamp:time.Time{wall:0xbf9b17b96e81e007, ext:43054089063, loc:(*time.Location)(0x7ae2160)}, Meta:null, Fields:{"agent":{"ephemeral_id":"89796327-ffaf-42cf-8253-a46cc53eecba","hostname":"blake-ubnt-1910","id":"1ef3d076-fd40-48aa-be57-f326f065df2c","type":"metricbeat","version":"7.7.0"},"ecs":{"version":"1.5.0"},"event":{"dataset":"istio.pilot","duration":5363690,"module":"istio"},"host":{"architecture":"x86_64","containerized":false,"hostname":"blake-ubnt-1910","id":"9e10a250f4d84241a49e269d5fa67023","ip":["192.168.150.130","fe80::cd85:816d:ec12:7218","172.17.0.1","172.18.0.1","172.20.0.1","172.19.0.1","10.1.62.0","fe80::14de:9aff:fe03:4d09","10.1.62.1","fe80::34a0:e2ff:fe33:988c","fe80::c88d:16ff:fe73:2b66","fe80::30c5:52ff:fe57:f970","fe80::b0cd:55ff:fed7:9fdd","fe80::8080:16ff:fec0:a3d8","fe80::e889:80ff:fe6e:8065","fe80::90cd:e5ff:fe73:e756","fe80::1c9e:e6ff:feb4:64d9","fe80::7893:f8ff:fe12:79c4","fe80::bcfa:fff:fe94:c68d","fe80::849:c3ff:feb7:f94e","fe80::ecba:39ff:fe71:79b9","fe80::20e9:c7ff:fe5a:a3a","fe80::2ca1:93ff:feaa:b000"],"mac":["00:0c:29:24:be:1d","02:42:ce:90:11:b6","02:42:da:76:c8:a8","02:42:b3:b1:5a:f5","02:42:88:e2:37:46","16:de:9a:03:4d:09","36:a0:e2:33:98:8c","ca:8d:16:73:2b:66","32:c5:52:57:f9:70","b2:cd:55:d7:9f:dd","82:80:16:c0:a3:d8","ea:89:80:6e:80:65","92:cd:e5:73:e7:56","1e:9e:e6:b4:64:d9","7a:93:f8:12:79:c4","be:fa:0f:94:c6:8d","0a:49:c3:b7:f9:4e","ee:ba:39:71:79:b9","22:e9:c7:5a:0a:3a","2e:a1:93:aa:b0:00"],"name":"blake-ubnt-1910","os":{"codename":"eoan","family":"debian","kernel":"5.3.0-45-generic","name":"Ubuntu","platform":"ubuntu","version":"19.10 (Eoan Ermine)"}},"istio":{"pilot":{"cluster":"outbound_.443_._.istio-ingressgateway.istio-system.svc.cluster.local","xds":{"eds":{"instances":1.000000}}}},"metricset":{"name":"pilot","period":10000},"service":{"address":"localhost:15014","type":"istio"}}, Private:interface {}(nil), TimeSeries:true}, Flags:0x0, Cache:publisher.EventCache{m:common.MapStr(nil)}} (status=400): {"type":"mapper_parsing_exception","reason":"object mapping for [istio.pilot.xds.eds.instances] tried to parse field [instances] as object, but found a concrete value"}

[elasticmachine]

Pinging @elastic/integrations-platforms (Team:Platforms)