[EBPF] manager: add BeforeStop method to modifiers

pkg/ebpf/helper_call_patcher.go

@@ -88,3 +88,7 @@ func (h *helperCallRemover) AfterInit(*manager.Manager, names.ModuleName, *manag
 func (h *helperCallRemover) String() string {
 	return fmt.Sprintf("HelperCallRemover[%+v]", h.helpers)
 }
+
+func (h *helperCallRemover) BeforeStop(*manager.Manager, names.ModuleName) error {
+	return nil
+}

pkg/ebpf/manager.go

@@ -8,6 +8,7 @@
 package ebpf
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"sync"
@@ -70,6 +71,10 @@ type Modifier interface {
 
 	// AfterInit is called after the ebpf.Manager.InitWithOptions call
 	AfterInit(*manager.Manager, names.ModuleName, *manager.Options) error
+
+	// BeforeStop is called after the ebpf.Manager.Stop call. Errors on these modifiers
+	// will not prevent the manager from stopping, but they will be reported.
+	BeforeStop(*manager.Manager, names.ModuleName) error
 }
 
 // InitWithOptions is a wrapper around ebpf-manager.Manager.InitWithOptions
@@ -100,3 +105,21 @@ func (m *Manager) InitWithOptions(bytecode io.ReaderAt, opts *manager.Options) e
 	}
 	return nil
 }
+
+// Stop is a wrapper around ebpf-manager.Manager.Stop
+func (m *Manager) Stop(clean manager.MapCleanupType) error {
+	var errs error
+
+	for _, mod := range m.EnabledModifiers {
+		log.Warnf("Running %s manager modifier BeforeStop", mod)
+		if err := mod.BeforeStop(m.Manager, m.Name); err != nil {
+			errs = errors.Join(errs, fmt.Errorf("error running %s manager modifier BeforeStop(): %s", mod, err))
+		}
+	}
+
+	if err := m.Manager.Stop(clean); err != nil {
+		errs = errors.Join(errs, fmt.Errorf("failed to stop manager %w", err))
+	}
+
+	return errs
+}

pkg/ebpf/manager_test.go

@@ -9,9 +9,10 @@ package ebpf
 import (
 	"testing"
 
-	"github.com/DataDog/datadog-agent/pkg/ebpf/names"
 	manager "github.com/DataDog/ebpf-manager"
 	"github.com/stretchr/testify/assert"
+
+	"github.com/DataDog/datadog-agent/pkg/ebpf/names"
 )
 
 // PrintkPatcherModifier adds an InstructionPatcher to the manager that removes the newline character from log_debug calls if needed
@@ -34,6 +35,11 @@ func (t *dummyModifier) AfterInit(_ *manager.Manager, _ names.ModuleName, _ *man
 	return nil
 }
 
+// BeforeStop is a no-op for this modifier
+func (t *dummyModifier) BeforeStop(_ *manager.Manager, _ names.ModuleName) error {
+	return nil
+}
+
 func TestNewManagerWithDefault(t *testing.T) {
 	type args struct {
 		mgr       *manager.Manager

pkg/ebpf/printk_patcher.go

@@ -227,3 +227,8 @@ func (t *PrintkPatcherModifier) BeforeInit(m *manager.Manager, _ names.ModuleNam
 func (t *PrintkPatcherModifier) AfterInit(_ *manager.Manager, _ names.ModuleName, _ *manager.Options) error {
 	return nil
 }
+
+// BeforeStop is a no-op for this modifier
+func (t *PrintkPatcherModifier) BeforeStop(_ *manager.Manager, _ names.ModuleName) error {
+	return nil
+}

pkg/ebpf/telemetry/modifier.go

@@ -135,3 +135,8 @@ func (t *ErrorsTelemetryModifier) AfterInit(m *manager.Manager, module names.Mod
 
 	return nil
 }
+
+// BeforeStop is a no-op for now
+func (t *ErrorsTelemetryModifier) BeforeStop(_ *manager.Manager, _ names.ModuleName) error {
+	return nil
+}