fix: ns exclusion audit from cache (#3129) cherry-pick for 3.14 (#3141)

Signed-off-by: Alex Pana <8968914+acpana@users.noreply.github.com>
Signed-off-by: alex <8968914+acpana@users.noreply.github.com>
Signed-off-by: Sertaç Özercan <852750+sozercan@users.noreply.github.com>
Co-authored-by: Sertaç Özercan <852750+sozercan@users.noreply.github.com>

pkg/audit/manager.go

@@ -508,6 +508,17 @@ func (am *Manager) auditFromCache(ctx context.Context) ([]Result, []error) {
 			ns = nil
 		}
 
+		excluded, err := am.skipExcludedNamespace(&obj)
+		if err != nil {
+			am.log.Error(err, "Unable to exclude object namespace for audit from cache %v %s/%s", obj.GroupVersionKind().String(), obj.GetNamespace(), obj.GetName())
+			continue
+		}
+
+		if excluded {
+			am.log.V(logging.DebugLevel).Info("excluding object from audit from cache %v %s/%s", obj.GroupVersionKind().String(), obj.GetNamespace(), obj.GetName())
+			continue
+		}
+
 		au := &target.AugmentedUnstructured{
 			Object:    obj,
 			Namespace: ns,

pkg/audit/manager_test.go

@@ -1,17 +1,115 @@
 package audit
 
 import (
+	"context"
 	"os"
 	"reflect"
 	"testing"
 
+	constraintclient "github.com/open-policy-agent/frameworks/constraint/pkg/client"
+	"github.com/open-policy-agent/frameworks/constraint/pkg/client/drivers/rego"
+	configv1alpha1 "github.com/open-policy-agent/gatekeeper/v3/apis/config/v1alpha1"
+	"github.com/open-policy-agent/gatekeeper/v3/pkg/controller/config/process"
+	"github.com/open-policy-agent/gatekeeper/v3/pkg/fakes"
+	"github.com/open-policy-agent/gatekeeper/v3/pkg/target"
+	"github.com/open-policy-agent/gatekeeper/v3/pkg/wildcard"
 	"github.com/pkg/errors"
+	"github.com/stretchr/testify/require"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
 )
 
+func Test_auditFromCache(t *testing.T) {
+	podToReview := fakes.Pod(fakes.WithNamespace("test-namespace-1"))
+	podGVK := podToReview.GroupVersionKind()
+	testAuditCache := fakeCacheListerFor([]schema.GroupVersionKind{podGVK}, []client.Object{podToReview})
+
+	driver, err := rego.New()
+	require.NoError(t, err)
+	client, err := constraintclient.NewClient(constraintclient.Targets(&target.K8sValidationTarget{}), constraintclient.Driver(driver))
+	require.NoError(t, err)
+
+	_, err = client.AddTemplate(context.Background(), fakes.DenyAllRegoTemplate())
+	require.NoError(t, err, "adding denyall constraint template")
+	_, err = client.AddConstraint(context.Background(), fakes.DenyAllConstraint())
+	require.NoError(t, err, "adding denyall constraint")
+
+	tests := []struct {
+		name            string
+		processExcluder *process.Excluder
+		wantViolation   bool
+	}{
+		{
+			name:            "obj excluded from audit",
+			processExcluder: processExcluderFor([]string{"test-namespace-1"}),
+		},
+		{
+			name:            "obj not excluded from audit",
+			processExcluder: processExcluderFor([]string{}),
+			wantViolation:   true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			am := &Manager{
+				processExcluder: tc.processExcluder,
+				auditCache:      testAuditCache,
+				opa:             client,
+			}
+
+			results, errs := am.auditFromCache(context.Background())
+			require.Len(t, errs, 0)
+
+			if tc.wantViolation {
+				require.Len(t, results, 1)
+			} else {
+				require.Len(t, results, 0)
+			}
+		})
+	}
+}
+
+func fakeCacheListerFor(gvks []schema.GroupVersionKind, objsToList []client.Object) *CacheLister {
+	k8sclient := fake.NewClientBuilder().WithObjects(objsToList...).Build()
+	fakeLister := fakeWatchIterator{gvksToList: gvks}
+
+	return NewAuditCacheLister(k8sclient, &fakeLister)
+}
+
+type fakeWatchIterator struct {
+	gvksToList []schema.GroupVersionKind
+}
+
+func (f *fakeWatchIterator) DoForEach(listFunc func(gvk schema.GroupVersionKind) error) error {
+	for _, gvk := range f.gvksToList {
+		if err := listFunc(gvk); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func processExcluderFor(ns []string) *process.Excluder {
+	processExcluder := process.New()
+	for _, n := range ns {
+		processExcluder.Add([]configv1alpha1.MatchEntry{
+			{
+				ExcludedNamespaces: []wildcard.Wildcard{wildcard.Wildcard(n)},
+				Processes:          []string{"audit"},
+			},
+		})
+	}
+
+	return processExcluder
+}
+
 func Test_newNSCache(t *testing.T) {
 	tests := []struct {
 		name string

pkg/fakes/fixtures.go

@@ -0,0 +1,63 @@
+package fakes
+
+import (
+	"github.com/open-policy-agent/frameworks/constraint/pkg/apis/constraints"
+	templatesv1beta1 "github.com/open-policy-agent/frameworks/constraint/pkg/apis/templates/v1beta1"
+	"github.com/open-policy-agent/frameworks/constraint/pkg/core/templates"
+	"github.com/open-policy-agent/gatekeeper/v3/pkg/target"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+func DenyAllRegoTemplate() *templates.ConstraintTemplate {
+	return &templates.ConstraintTemplate{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: templatesv1beta1.SchemeGroupVersion.String(),
+			Kind:       "ConstraintTemplate",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "denyall",
+		},
+		Spec: templates.ConstraintTemplateSpec{
+			CRD: templates.CRD{
+				Spec: templates.CRDSpec{
+					Names: templates.Names{
+						Kind: "denyall",
+					},
+				},
+			},
+			Targets: []templates.Target{{
+				Target: target.Name,
+				Code: []templates.Code{{
+					Engine: "Rego",
+					Source: &templates.Anything{
+						Value: map[string]interface{}{"rego": `
+package goodrego
+
+violation[{"msg": msg}] {
+   msg := "denyall"
+}`},
+					},
+				}},
+			}},
+		},
+	}
+}
+
+func DenyAllConstraint() *unstructured.Unstructured {
+	return ConstraintFor("denyall")
+}
+
+func ConstraintFor(kind string) *unstructured.Unstructured {
+	u := &unstructured.Unstructured{}
+
+	u.SetGroupVersionKind(schema.GroupVersionKind{
+		Group:   constraints.Group,
+		Version: "v1beta1",
+		Kind:    kind,
+	})
+	u.SetName("constraint")
+
+	return u
+}