discovery: send Service Discovery telemetry (#35869)

Author: Yumasi

comp/core/agenttelemetry/impl/agenttelemetry_test.go

@@ -478,7 +478,7 @@ func TestRun(t *testing.T) {
 	profile0Len := len(r.(*runnerMock).jobs[0].profiles)
 	profile1Len := len(r.(*runnerMock).jobs[1].profiles)
 	t.Logf("%+v", r.(*runnerMock).jobs)
-	assert.True(t, (profile0Len == 1 && profile1Len == 4) || (profile0Len == 4 && profile1Len == 1))
+	assert.True(t, (profile0Len == 1 && profile1Len == 5) || (profile0Len == 5 && profile1Len == 1))
 }
 
 func TestReportMetricBasic(t *testing.T) {

comp/core/agenttelemetry/impl/config.go

@@ -283,6 +283,14 @@ var defaultProfiles = `
           aggregate_tags:
             - kind
             - template_name
+  - name: service-discovery
+    metric:
+      metrics:
+        - name: service_discovery.discovered_services
+    schedule:
+      start_after: 30
+      iterations: 0
+      period: 900
 `
 
 func compileMetricsExclude(p *Profile) error {

pkg/collector/corechecks/servicediscovery/servicediscovery.go

@@ -94,7 +94,7 @@ func (c *Check) Configure(senderManager sender.SenderManager, _ uint64, instance
 		"discovered_services",
 		[]string{},
 		"Number of discovered alive services.",
-		telemetry.Options{NoDoubleUnderscoreSep: true},
+		telemetry.DefaultOptions,
 	)
 
 	return nil

releasenotes/notes/service-discovery-telemetry-2d18d23177699523.yaml

@@ -0,0 +1,11 @@
+# Each section from every release note are combined when the
+# CHANGELOG.rst is rendered. So the text needs to be worded so that
+# it does not depend on any information only available in another
+# section. This may mean repeating some details, but each section
+# must be readable independently of the other.
+#
+# Each section note must be formatted as reStructuredText.
+---
+other:
+  - |
+    Adds Agent telemetry for Service Discovery.