usm: Move USM telemetry repoter to the USM monitor

The telemetry go-routine, was incorrectly placed in the network-tracer. We move the logic into
the USM monitor, before further changing it

cmd/system-probe/modules/network_tracer.go

@@ -36,7 +36,6 @@ import (
 	"github.com/DataDog/datadog-agent/pkg/network/tracer"
 	usmconsts "github.com/DataDog/datadog-agent/pkg/network/usm/consts"
 	usm "github.com/DataDog/datadog-agent/pkg/network/usm/utils"
-	"github.com/DataDog/datadog-agent/pkg/process/statsd"
 	"github.com/DataDog/datadog-agent/pkg/util/log"
 )
 
@@ -67,19 +66,13 @@ func createNetworkTracerModule(_ *sysconfigtypes.Config, deps module.FactoryDepe
 
 	t, err := tracer.NewTracer(ncfg, deps.Telemetry)
 
-	done := make(chan struct{})
-	if err == nil {
-		startTelemetryReporter(done)
-	}
-
-	return &networkTracer{tracer: t, done: done}, err
+	return &networkTracer{tracer: t}, err
 }
 
 var _ module.Module = &networkTracer{}
 
 type networkTracer struct {
 	tracer       *tracer.Tracer
-	done         chan struct{}
 	restartTimer *time.Timer
 }
 
@@ -322,7 +315,6 @@ func (nt *networkTracer) Register(httpMux *module.Router) error {
 
 // Close will stop all system probe activities
 func (nt *networkTracer) Close() {
-	close(nt.done)
 	nt.tracer.Stop()
 }
 
@@ -363,23 +355,6 @@ func writeConnections(w http.ResponseWriter, marshaler marshal.Marshaler, cs *ne
 	log.Tracef("/connections: %d connections", len(cs.Conns))
 }
 
-func startTelemetryReporter(done <-chan struct{}) {
-	telemetry.SetStatsdClient(statsd.Client)
-	ticker := time.NewTicker(30 * time.Second)
-	go func() {
-		defer ticker.Stop()
-
-		for {
-			select {
-			case <-ticker.C:
-				telemetry.ReportStatsd()
-			case <-done:
-				return
-			}
-		}
-	}()
-}
-
 func writeDisabledProtocolMessage(protocolName string, w http.ResponseWriter) {
 	log.Warnf("%s monitoring is disabled", protocolName)
 	w.WriteHeader(404)

pkg/network/usm/monitor.go

@@ -29,6 +29,7 @@ import (
 	usmstate "github.com/DataDog/datadog-agent/pkg/network/usm/state"
 	"github.com/DataDog/datadog-agent/pkg/network/usm/utils"
 	"github.com/DataDog/datadog-agent/pkg/process/monitor"
+	"github.com/DataDog/datadog-agent/pkg/process/statsd"
 	"github.com/DataDog/datadog-agent/pkg/util/log"
 )
 
@@ -51,6 +52,8 @@ type Monitor struct {
 	closeFilterFn func()
 
 	lastUpdateTime *atomic.Int64
+
+	telemetryStopChannel chan struct{}
 }
 
 // NewMonitor returns a new Monitor instance
@@ -95,10 +98,11 @@ func NewMonitor(c *config.Config, connectionProtocolMap *ebpf.Map) (m *Monitor,
 	usmstate.Set(usmstate.Running)
 
 	usmMonitor := &Monitor{
-		cfg:            c,
-		ebpfProgram:    mgr,
-		closeFilterFn:  closeFilterFn,
-		processMonitor: processMonitor,
+		cfg:                  c,
+		ebpfProgram:          mgr,
+		closeFilterFn:        closeFilterFn,
+		processMonitor:       processMonitor,
+		telemetryStopChannel: make(chan struct{}),
 	}
 
 	usmMonitor.lastUpdateTime = atomic.NewInt64(time.Now().Unix())
@@ -138,7 +142,11 @@ func (m *Monitor) Start() error {
 		err = m.processMonitor.Initialize(m.cfg.EnableUSMEventStream)
 	}
 
-	return err
+	if err != nil {
+		return err
+	}
+	m.startTelemetryReporter()
+	return nil
 }
 
 // Pause bypasses the eBPF programs in the monitor
@@ -202,6 +210,9 @@ func (m *Monitor) Stop() {
 		return
 	}
 
+	if m.telemetryStopChannel != nil {
+		close(m.telemetryStopChannel)
+	}
 	m.processMonitor.Stop()
 
 	ddebpf.RemoveNameMappings(m.ebpfProgram.Manager.Manager)
@@ -215,3 +226,20 @@ func (m *Monitor) Stop() {
 func (m *Monitor) DumpMaps(w io.Writer, maps ...string) error {
 	return m.ebpfProgram.DumpMaps(w, maps...)
 }
+
+func (m *Monitor) startTelemetryReporter() {
+	telemetry.SetStatsdClient(statsd.Client)
+	ticker := time.NewTicker(30 * time.Second)
+	go func() {
+		defer ticker.Stop()
+
+		for {
+			select {
+			case <-ticker.C:
+				telemetry.ReportStatsd()
+			case <-m.telemetryStopChannel:
+				return
+			}
+		}
+	}()
+}