xds: E2E Test for Audit Logging (#6377)

Add E2E Test for Audit Logging through the XDS path

test/xds/xds_server_rbac_test.go

@@ -20,14 +20,18 @@ package xds_test
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"net"
 	"strconv"
 	"strings"
 	"testing"
 
+	v3xdsxdstypepb "github.com/cncf/xds/go/xds/type/v3"
 	v3routerpb "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/http/router/v3"
+	"github.com/google/go-cmp/cmp"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/authz/audit"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/internal"
@@ -36,6 +40,7 @@ import (
 	"google.golang.org/grpc/internal/testutils/xds/e2e"
 	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/anypb"
+	"google.golang.org/protobuf/types/known/structpb"
 
 	v3corepb "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
 	v3listenerpb "github.com/envoyproxy/go-control-plane/envoy/config/listener/v3"
@@ -415,6 +420,8 @@ func (s) TestRBACHTTPFilter(t *testing.T) {
 		rbacCfg             *rpb.RBAC
 		wantStatusEmptyCall codes.Code
 		wantStatusUnaryCall codes.Code
+		wantAuthzOutcomes   map[bool]int
+		eventContent        *audit.Event
 	}{
 		// This test tests an RBAC HTTP Filter which is configured to allow any RPC.
 		// Any RPC passing through this RBAC HTTP Filter should proceed as normal.
@@ -433,10 +440,30 @@ func (s) TestRBACHTTPFilter(t *testing.T) {
 							},
 						},
 					},
+					AuditLoggingOptions: &v3rbacpb.RBAC_AuditLoggingOptions{
+						AuditCondition: v3rbacpb.RBAC_AuditLoggingOptions_ON_ALLOW,
+						LoggerConfigs: []*v3rbacpb.RBAC_AuditLoggingOptions_AuditLoggerConfig{
+							{
+								AuditLogger: &v3corepb.TypedExtensionConfig{
+									Name:        "stat_logger",
+									TypedConfig: createXDSTypedStruct(t, map[string]interface{}{}, "stat_logger"),
+								},
+								IsOptional: false,
+							},
+						},
+					},
 				},
 			},
 			wantStatusEmptyCall: codes.OK,
 			wantStatusUnaryCall: codes.OK,
+			wantAuthzOutcomes:   map[bool]int{true: 2, false: 0},
+			// TODO(gtcooke94) add policy name (RBAC filter name) once
+			// https://github.com/grpc/grpc-go/pull/6327 is merged.
+			eventContent: &audit.Event{
+				FullMethodName: "/grpc.testing.TestService/UnaryCall",
+				MatchedRule:    "anyone",
+				Authorized:     true,
+			},
 		},
 		// This test tests an RBAC HTTP Filter which is configured to allow only
 		// RPC's with certain paths ("UnaryCall"). Only unary calls passing
@@ -605,6 +632,12 @@ func (s) TestRBACHTTPFilter(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			func() {
+				lb := &loggerBuilder{
+					authzDecisionStat: map[bool]int{true: 0, false: 0},
+					lastEvent:         &audit.Event{},
+				}
+				audit.RegisterLoggerBuilder(lb)
+
 				managementServer, nodeID, bootstrapContents, resolver, cleanup1 := e2e.SetupManagementServer(t, e2e.ManagementServerOptions{})
 				defer cleanup1()
 
@@ -660,6 +693,17 @@ func (s) TestRBACHTTPFilter(t *testing.T) {
 				}
 				// Toggle RBAC back on for next iterations.
 				envconfig.XDSRBAC = true
+
+				if test.wantAuthzOutcomes != nil {
+					if diff := cmp.Diff(lb.authzDecisionStat, test.wantAuthzOutcomes); diff != "" {
+						t.Fatalf("authorization decision do not match\ndiff (-got +want):\n%s", diff)
+					}
+				}
+				if test.eventContent != nil {
+					if diff := cmp.Diff(lb.lastEvent, test.eventContent); diff != "" {
+						t.Fatalf("unexpected event\ndiff (-got +want):\n%s", diff)
+					}
+				}
 			}()
 		})
 	}
@@ -895,3 +939,55 @@ func (s) TestRBACToggledOff_WithBadRouteConfiguration(t *testing.T) {
 		t.Fatalf("UnaryCall() returned err with status: %v, if RBAC is disabled all RPC's should proceed as normal", status.Code(err))
 	}
 }
+
+type statAuditLogger struct {
+	authzDecisionStat map[bool]int // Map to hold counts of authorization decisions
+	lastEvent         *audit.Event // Field to store last received event
+}
+
+func (s *statAuditLogger) Log(event *audit.Event) {
+	s.authzDecisionStat[event.Authorized]++
+	*s.lastEvent = *event
+}
+
+type loggerBuilder struct {
+	authzDecisionStat map[bool]int
+	lastEvent         *audit.Event
+}
+
+func (loggerBuilder) Name() string {
+	return "stat_logger"
+}
+
+func (lb *loggerBuilder) Build(audit.LoggerConfig) audit.Logger {
+	return &statAuditLogger{
+		authzDecisionStat: lb.authzDecisionStat,
+		lastEvent:         lb.lastEvent,
+	}
+}
+
+func (*loggerBuilder) ParseLoggerConfig(config json.RawMessage) (audit.LoggerConfig, error) {
+	return nil, nil
+}
+
+// This is used when converting a custom config from raw JSON to a TypedStruct.
+// The TypeURL of the TypeStruct will be "grpc.authz.audit_logging/<name>".
+const typeURLPrefix = "grpc.authz.audit_logging/"
+
+// Builds custom configs for audit logger RBAC protos.
+func createXDSTypedStruct(t *testing.T, in map[string]interface{}, name string) *anypb.Any {
+	t.Helper()
+	pb, err := structpb.NewStruct(in)
+	if err != nil {
+		t.Fatalf("createXDSTypedStruct failed during structpb.NewStruct: %v", err)
+	}
+	typedStruct := &v3xdsxdstypepb.TypedStruct{
+		TypeUrl: typeURLPrefix + name,
+		Value:   pb,
+	}
+	customConfig, err := anypb.New(typedStruct)
+	if err != nil {
+		t.Fatalf("createXDSTypedStruct failed during anypb.New: %v", err)
+	}
+	return customConfig
+}