Fix functional tests

pkg/security/resolvers/cgroup/resolver.go

@@ -32,6 +32,17 @@ const (
 	CGroupMaxEvent
 )
 
+// ResolverInterface defines the interface implemented by a cgroup resolver
+type ResolverInterface interface {
+	Start(context.Context)
+	AddPID(*model.ProcessCacheEntry)
+	GetWorkload(string) (*cgroupModel.CacheEntry, bool)
+	DelPID(uint32)
+	DelPIDWithID(string, uint32)
+	Len() int
+	RegisterListener(Event, utils.Listener[*cgroupModel.CacheEntry]) error
+}
+
 // Resolver defines a cgroup monitor
 type Resolver struct {
 	*utils.Notifier[Event, *cgroupModel.CacheEntry]
@@ -48,7 +59,7 @@ func NewResolver() (*Resolver, error) {
 		value.CallReleaseCallback()
 		value.Deleted.Store(true)
 
-		cr.NotifyListener(CGroupDeleted, value)
+		cr.NotifyListeners(CGroupDeleted, value)
 	})
 	if err != nil {
 		return nil, err
@@ -84,7 +95,7 @@ func (cr *Resolver) AddPID(process *model.ProcessCacheEntry) {
 	// add the new CGroup to the cache
 	cr.workloads.Add(string(process.ContainerID), newCGroup)
 
-	cr.NotifyListener(CGroupCreated, newCGroup)
+	cr.NotifyListeners(CGroupCreated, newCGroup)
 }
 
 // GetWorkload returns the workload referenced by the provided ID

pkg/security/resolvers/resolvers_ebpf.go

@@ -195,7 +195,7 @@ func (r *EBPFResolvers) Start(ctx context.Context) error {
 		return err
 	}
 
-	if err := r.TagsResolver.Start(ctx); err != nil {
+	if err := r.TagsResolver.Start(ctx, r.CGroupResolver); err != nil {
 		return err
 	}
 

pkg/security/resolvers/resolvers_ebpfless.go

@@ -73,7 +73,7 @@ func (r *EBPFLessResolvers) Start(ctx context.Context) error {
 		return err
 	}
 
-	if err := r.TagsResolver.Start(ctx); err != nil {
+	if err := r.TagsResolver.Start(ctx, nil); err != nil {
 		return err
 	}
 

pkg/security/resolvers/tags/resolver.go

@@ -19,6 +19,7 @@ import (
 	"github.com/DataDog/datadog-agent/pkg/api/security"
 	pkgconfigsetup "github.com/DataDog/datadog-agent/pkg/config/setup"
 	"github.com/DataDog/datadog-agent/pkg/security/probe/config"
+	"github.com/DataDog/datadog-agent/pkg/security/resolvers/cgroup"
 	cgroupModel "github.com/DataDog/datadog-agent/pkg/security/resolvers/cgroup/model"
 	"github.com/DataDog/datadog-agent/pkg/security/utils"
 	"github.com/DataDog/datadog-agent/pkg/util/log"
@@ -55,10 +56,10 @@ func (n *nullTagger) Tag(_ types.EntityID, _ types.TagCardinality) ([]string, er
 
 // Resolver represents a cache resolver
 type Resolver interface {
-	Start(ctx context.Context) error
+	Start(ctx context.Context, cgroupManager cgroup.ResolverInterface) error
 	Stop() error
 	Resolve(id string) []string
-	ResolveWithErr(id string) ([]string, error)
+	ResolveWithErr(fid string) ([]string, error)
 	GetValue(id string, tag string) string
 	RegisterListener(event Event, listener utils.Listener[*cgroupModel.CacheEntry]) error
 }
@@ -94,7 +95,7 @@ func (t *DefaultResolver) GetValue(id string, tag string) string {
 }
 
 // Start the resolver
-func (t *DefaultResolver) Start(ctx context.Context) error {
+func (t *DefaultResolver) Start(ctx context.Context, _ cgroup.ResolverInterface) error {
 	go func() {
 		if err := t.tagger.Start(ctx); err != nil {
 			log.Errorf("failed to init tagger: %s", err)

pkg/security/resolvers/tags/resolver_linux.go

@@ -25,12 +25,12 @@ type LinuxResolver struct {
 }
 
 // Start the resolver
-func (t *LinuxResolver) Start(ctx context.Context) error {
-	if err := t.DefaultResolver.Start(ctx); err != nil {
+func (t *LinuxResolver) Start(ctx context.Context, cgroupResolver cgroup.ResolverInterface) error {
+	if err := t.DefaultResolver.Start(ctx, cgroupResolver); err != nil {
 		return err
 	}
 
-	if err := t.cgroupResolver.RegisterListener(cgroup.CGroupCreated, t.checkTags); err != nil {
+	if err := cgroupResolver.RegisterListener(cgroup.CGroupCreated, t.checkTags); err != nil {
 		return err
 	}
 
@@ -74,7 +74,7 @@ func (t *LinuxResolver) checkTags(workload *cgroupModel.CacheEntry) {
 		}
 	}
 
-	t.NotifyListener(WorkloadSelectorResolved, workload)
+	t.NotifyListeners(WorkloadSelectorResolved, workload)
 }
 
 // fetchTags fetches tags for the provided workload

pkg/security/tests/fake_tags_resolver.go

@@ -13,6 +13,7 @@ import (
 	"fmt"
 	"sync"
 
+	"github.com/DataDog/datadog-agent/pkg/security/resolvers/cgroup"
 	cgroupModel "github.com/DataDog/datadog-agent/pkg/security/resolvers/cgroup/model"
 	"github.com/DataDog/datadog-agent/pkg/security/resolvers/tags"
 	"github.com/DataDog/datadog-agent/pkg/security/utils"
@@ -27,9 +28,14 @@ type FakeResolver struct {
 	containerIDs []string
 }
 
+// checkTags checks if the tags of a workload were properly set
+func (fr *FakeResolver) checkTags(workload *cgroupModel.CacheEntry) {
+	fr.NotifyListeners(tags.WorkloadSelectorResolved, workload)
+}
+
 // Start the resolver
-func (fr *FakeResolver) Start(_ context.Context) error {
-	return nil
+func (fr *FakeResolver) Start(_ context.Context, cgroupResolver cgroup.ResolverInterface) error {
+	return cgroupResolver.RegisterListener(cgroup.CGroupCreated, fr.checkTags)
 }
 
 // Stop the resolver
@@ -77,9 +83,14 @@ type FakeMonoResolver struct {
 	*utils.Notifier[tags.Event, *cgroupModel.CacheEntry]
 }
 
+// checkTags checks if the tags of a workload were properly set
+func (fmr *FakeMonoResolver) checkTags(workload *cgroupModel.CacheEntry) {
+	fmr.NotifyListeners(tags.WorkloadSelectorResolved, workload)
+}
+
 // Start the resolver
-func (fmr *FakeMonoResolver) Start(_ context.Context) error {
-	return nil
+func (fmr *FakeMonoResolver) Start(_ context.Context, cgroupResolver cgroup.ResolverInterface) error {
+	return cgroupResolver.RegisterListener(cgroup.CGroupCreated, fmr.checkTags)
 }
 
 // Stop the resolver
@@ -120,9 +131,14 @@ type FakeManualResolver struct {
 	nextSelectors       []*cgroupModel.WorkloadSelector
 }
 
+// checkTags checks if the tags of a workload were properly set
+func (fmr *FakeManualResolver) checkTags(workload *cgroupModel.CacheEntry) {
+	fmr.NotifyListeners(tags.WorkloadSelectorResolved, workload)
+}
+
 // Start the resolver
-func (fmr *FakeManualResolver) Start(_ context.Context) error {
-	return nil
+func (fmr *FakeManualResolver) Start(_ context.Context, cgroupResolver cgroup.ResolverInterface) error {
+	return cgroupResolver.RegisterListener(cgroup.CGroupCreated, fmr.checkTags)
 }
 
 // Stop the resolver

pkg/security/utils/notifier.go

@@ -35,7 +35,8 @@ func (n *Notifier[E, O]) RegisterListener(event E, listener Listener[O]) error {
 	return nil
 }
 
-func (n *Notifier[E, O]) NotifyListener(event E, obj O) {
+// NotifyListeners notifies all listeners of an event type
+func (n *Notifier[E, O]) NotifyListeners(event E, obj O) {
 	// notify listeners
 	n.listenersLock.RLock()
 	for _, l := range n.listeners[event] {