Change lookup_field to service.address. (#15883) (#15927)

* Change lookup_field to service.address. Using metricset.host is not setting application_id

(cherry picked from commit f179f39)

Co-authored-by: premendrasingh <premendrasingh@hotmail.com>
Co-authored-by: kaiyan-sheng <kaiyan.sheng@elastic.co>

CHANGELOG.next.asciidoc

@@ -116,6 +116,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Fix CPU count in docker/cpu in cases where no `online_cpus` are reported {pull}15070[15070]
 - Add dedot for tags in ec2 metricset and cloudwatch metricset. {issue}15843[15843] {pull}15844[15844]
 - Use RFC3339 format for timestamps collected using the SQL module. {pull}15847[15847]
+- Change lookup_fields from metricset.host to service.address {pull}15883[15883]
 - Avoid parsing errors returned from prometheus endpoints. {pull}15712[15712]
 - Add dedot for cloudwatch metric name. {issue}15916[15916] {pull}15917[15917]
 - Fixed issue `logstash-xpack` module suddenly ceasing to monitor Logstash. {issue}15974[15974] {pull}16044[16044]

metricbeat/processor/add_kubernetes_metadata/indexers.go

@@ -30,7 +30,7 @@ func init() {
 	kubernetes.Indexing.AddDefaultIndexerConfig(kubernetes.IPPortIndexerName, *cfg)
 
 	config := map[string]interface{}{
-		"lookup_fields": []string{"metricset.host"},
+		"lookup_fields": []string{"service.address"},
 	}
 	fieldCfg, err := common.NewConfigFrom(config)
 	if err == nil {