Add username/password in Metricbeat autodiscover hints

CHANGELOG.next.asciidoc

@@ -301,6 +301,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Fix `docker.container.size` fields values {issue}14979[14979] {pull}15224[15224]
 - Make `kibana` module more resilient to Kibana unavailability. {issue}15258[15258] {pull}15270[15270]
 - Make `logstash` module more resilient to Logstash unavailability. {issue}15276[15276] {pull}15306[15306]
+- Add username/password in Metricbeat autodiscover hints {pull}15349[15349]
 
 *Packetbeat*
 

libbeat/autodiscover/builder/helper_test.go

@@ -78,6 +78,8 @@ func TestGenerateHints(t *testing.T) {
 				"co.elastic.metrics/module":         "prometheus",
 				"co.elastic.metrics/period":         "10s",
 				"co.elastic.metrics/metrics_path":   "/metrics/prometheus",
+				"co.elastic.metrics/username":       "user",
+				"co.elastic.metrics/password":       "pass",
 				"co.elastic.metrics.foobar/period":  "15s",
 				"co.elastic.metrics.foobar1/period": "15s",
 				"not.to.include":                    "true",
@@ -92,6 +94,8 @@ func TestGenerateHints(t *testing.T) {
 					"module":       "prometheus",
 					"period":       "15s",
 					"metrics_path": "/metrics/prometheus",
+					"username":     "user",
+					"password":     "pass",
 				},
 			},
 		},

metricbeat/autodiscover/builder/hints/metrics.go

@@ -44,6 +44,8 @@ const (
 	timeout     = "timeout"
 	ssl         = "ssl"
 	metricspath = "metrics_path"
+	username    = "username"
+	password    = "password"
 
 	defaultTimeout = "3s"
 	defaultPeriod  = "1m"
@@ -112,6 +114,8 @@ func (m *metricHints) CreateConfig(event bus.Event) []*common.Config {
 	sslConf := m.getSSLConfig(hints)
 	procs := m.getProcessors(hints)
 	metricspath := m.getMetricPath(hints)
+	username := m.getUsername(hints)
+	password := m.getPassword(hints)
 
 	moduleConfig := common.MapStr{
 		"module":     mod,
@@ -130,6 +134,12 @@ func (m *metricHints) CreateConfig(event bus.Event) []*common.Config {
 	if metricspath != "" {
 		moduleConfig["metrics_path"] = metricspath
 	}
+	if username != "" {
+		moduleConfig["username"] = username
+	}
+	if password != "" {
+		moduleConfig["password"] = password
+	}
 
 	logp.Debug("hints.builder", "generated config: %v", moduleConfig.String())
 
@@ -198,6 +208,14 @@ func (m *metricHints) getMetricPath(hints common.MapStr) string {
 	return builder.GetHintString(hints, m.Key, metricspath)
 }
 
+func (m *metricHints) getUsername(hints common.MapStr) string {
+	return builder.GetHintString(hints, m.Key, username)
+}
+
+func (m *metricHints) getPassword(hints common.MapStr) string {
+	return builder.GetHintString(hints, m.Key, password)
+}
+
 func (m *metricHints) getPeriod(hints common.MapStr) string {
 	if ival := builder.GetHintString(hints, m.Key, period); ival != "" {
 		return ival

metricbeat/docs/autodiscover-hints.asciidoc

@@ -35,6 +35,16 @@ The time interval for metrics retrieval, ie: 10s
 
 Metrics retrieval timeout, default: 3s
 
+[float]
+===== `co.elastic.metrics/username`
+
+The username to use for authentication
+
+[float]
+===== `co.elastic.metrics/password`
+
+The password to use for authentication. It is recommended to retrieve this sensitive information from an ENV variable or a keystore and avoid placing passwords in plain text
+
 [float]
 ===== `co.elastic.metrics/ssl.*`