[Elastic Agent] Add stream.* to metrics and logs collected (elastic#1…

…8261)

* [Elastic Agent] Add stream.* to metrics and logs collected

This PR ensure that the stream.type, stream.dataset and stream.namespace
are added to each logs or metrics collected by the Agent.

Fixes: elastic#18203
(cherry picked from commit 7b87db5)

x-pack/elastic-agent/CHANGELOG.asciidoc

@@ -29,6 +29,7 @@
 - Use default output by default {pull}18091[18091]
 - Fix panic and flaky tests for the Agent. {pull}18135[18135]
 - Fix default configuration after enroll {pull}18232[18232]
+- Fix make sure the collected logs or metrics include streams information. {pull}18261[18261]
 
 ==== New features
 

x-pack/elastic-agent/pkg/agent/operation/monitoring.go

@@ -171,6 +171,18 @@ func (o *Operator) getMonitoringFilebeatConfig(output interface{}) (map[string]i
 					"type":  "log",
 					"paths": paths,
 					"index": "logs-agent-default",
+					"processors": []map[string]interface{}{
+						map[string]interface{}{
+							"add_fields": map[string]interface{}{
+								"target": "stream",
+								"fields": map[string]interface{}{
+									"type":      "logs",
+									"dataset":   "agent",
+									"namespace": "default",
+								},
+							},
+						},
+					},
 				},
 			},
 		},
@@ -199,6 +211,18 @@ func (o *Operator) getMonitoringMetricbeatConfig(output interface{}) (map[string
 					"period":     "10s",
 					"hosts":      hosts,
 					"index":      "metrics-agent-default",
+					"processors": []map[string]interface{}{
+						map[string]interface{}{
+							"add_fields": map[string]interface{}{
+								"target": "stream",
+								"fields": map[string]interface{}{
+									"type":      "metrics",
+									"dataset":   "agent",
+									"namespace": "default",
+								},
+							},
+						},
+					},
 				},
 			},
 		},