tetragon: Load base sensor via sensor manager

cmd/tetragon/main.go

@@ -481,12 +481,9 @@ func tetragonExecute() error {
 
 	// load base sensor
 	initialSensor := base.GetInitialSensor()
-	if err := initialSensor.Load(observerDir); err != nil {
+	if err := observer.GetSensorManager().LoadSensor(initialSensor); err != nil {
 		return err
 	}
-	defer func() {
-		initialSensor.Unload()
-	}()
 
 	cgrouprate.NewCgroupRate(ctx, pm, base.CgroupRateMap, &option.Config.CgroupRate)
 	cgrouprate.Config(base.CgroupRateOptionsMap)

pkg/sensors/collection.go

@@ -74,13 +74,15 @@ type collection struct {
 
 type collectionMap struct {
 	// map of sensor collections: name, namespace -> collection
-	c  map[collectionKey]*collection
-	mu sync.RWMutex
+	c      map[collectionKey]*collection
+	mu     sync.RWMutex
+	bpfDir string
 }
 
-func newCollectionMap() *collectionMap {
+func newCollectionMap(bpfDir string) *collectionMap {
 	return &collectionMap{
-		c: map[collectionKey]*collection{},
+		c:      map[collectionKey]*collection{},
+		bpfDir: bpfDir,
 	}
 }
 
@@ -144,6 +146,28 @@ func (c *collection) destroy() {
 	}
 }
 
+func (cm *collectionMap) loadSensor(s *Sensor) error {
+	cm.mu.Lock()
+	defer cm.mu.Unlock()
+
+	collections := cm.c
+	// Treat sensors as cluster-wide operations
+	ck := collectionKey{s.Name, ""}
+	if _, exists := collections[ck]; exists {
+		return fmt.Errorf("sensor %s already exists", ck)
+	}
+	col := &collection{
+		sensors: []SensorIface{s},
+		name:    s.Name,
+	}
+	if err := col.load(cm.bpfDir); err != nil {
+		return err
+	}
+	col.state = EnabledState
+	collections[ck] = col
+	return nil
+}
+
 func (cm *collectionMap) listPolicies() []*tetragon.TracingPolicyStatus {
 	cm.mu.RLock()
 	defer cm.mu.RUnlock()

pkg/sensors/manager.go

@@ -48,7 +48,7 @@ func StartSensorManagerWithPF(
 	waitChan chan struct{},
 	pfState policyfilter.State,
 ) (*Manager, error) {
-	colMap := newCollectionMap()
+	colMap := newCollectionMap(bpfDir)
 
 	handler, err := newHandler(pfState, colMap, bpfDir)
 	if err != nil {
@@ -62,13 +62,13 @@ func StartSensorManagerWithPF(
 
 func startSensorManager(
 	handler *handler,
-	policyLister policyLister,
+	directAccess directAccess,
 	waitChan chan struct{},
 ) (*Manager, error) {
 	c := make(chan sensorOp)
 	m := Manager{
 		sensorCtl:    c,
-		policyLister: policyLister,
+		directAccess: directAccess,
 	}
 
 	go func() {
@@ -267,6 +267,10 @@ func (h *Manager) ListTracingPolicies(_ context.Context) (*tetragon.ListTracingP
 	return ret, nil
 }
 
+func (h *Manager) LoadSensor(s *Sensor) error {
+	return h.loadSensor(s)
+}
+
 func (h *Manager) RemoveSensor(ctx context.Context, sensorName string) error {
 	retc := make(chan error)
 	op := &sensorRemove{
@@ -332,19 +336,20 @@ func (h *Manager) LogSensorsAndProbes(ctx context.Context) {
 	log.WithField("types", strings.Join(names, ", ")).Info("Registered probe types")
 }
 
-// policyLister allows read-only access to the collections map
-type policyLister interface {
+// directAccess allows access to the collections map
+type directAccess interface {
 	listPolicies() []*tetragon.TracingPolicyStatus
+	loadSensor(s *Sensor) error
 }
 
 // Manager handles dynamic sensor management, such as adding / removing sensors
 // at runtime.
 type Manager struct {
 	// channel to communicate with the controller goroutine
 	sensorCtl sensorCtlHandle
-	// policyLister is used to list policies without going via the controller goroutine by
-	// directly accessing the collection.
-	policyLister
+	// directAccess is used to access collection directly without
+	// going via the controller goroutine
+	directAccess
 }
 
 // There are 6 commands that can be passed to the controller goroutine:

pkg/sensors/manager_test.go

@@ -157,7 +157,7 @@ func TestPolicyFilterDisabled(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 
-	handler, err := newHandler(policyfilter.DisabledState(), newCollectionMap(), "")
+	handler, err := newHandler(policyfilter.DisabledState(), newCollectionMap(""), "")
 	assert.NoError(t, err)
 	mgr, err := startSensorManager(handler, handler.collections, nil)
 	assert.NoError(t, err)