Files
Karl Persson e0163c93c2 Zanzana: reconcile generic schema (#95492)
* Rename to CheckObject

* Implement authz.AccessClient

* Move folder tree to reconciler and use new schema

* Move shared functionality to common package

* Add reconciler for managed permissions and resource translations

* Add support for folder resources
2024-10-28 16:32:16 +01:00

285 lines
8.3 KiB
Go

package acimpl
import (
"context"
"errors"
"strconv"
"time"
openfgav1 "github.com/openfga/api/proto/openfga/v1"
"github.com/prometheus/client_golang/prometheus"
"go.opentelemetry.io/otel"
"github.com/grafana/authlib/claims"
"github.com/grafana/grafana/pkg/apimachinery/identity"
"github.com/grafana/grafana/pkg/infra/log"
"github.com/grafana/grafana/pkg/infra/metrics"
"github.com/grafana/grafana/pkg/services/accesscontrol"
"github.com/grafana/grafana/pkg/services/authz/zanzana"
"github.com/grafana/grafana/pkg/services/featuremgmt"
)
var (
errAccessNotImplemented = errors.New("access control not implemented for resource")
tracer = otel.Tracer("github.com/grafana/grafana/pkg/services/accesscontrol/acimpl")
)
var _ accesscontrol.AccessControl = new(AccessControl)
func ProvideAccessControl(features featuremgmt.FeatureToggles, zclient zanzana.Client) *AccessControl {
logger := log.New("accesscontrol")
var m *acMetrics
if features.IsEnabledGlobally(featuremgmt.FlagZanzana) {
m = initMetrics()
}
return &AccessControl{
features,
logger,
accesscontrol.NewResolvers(logger),
zclient,
m,
}
}
func ProvideAccessControlTest() *AccessControl {
return ProvideAccessControl(featuremgmt.WithFeatures(), zanzana.NewNoopClient())
}
type AccessControl struct {
features featuremgmt.FeatureToggles
log log.Logger
resolvers accesscontrol.Resolvers
zclient zanzana.Client
metrics *acMetrics
}
func (a *AccessControl) Evaluate(ctx context.Context, user identity.Requester, evaluator accesscontrol.Evaluator) (bool, error) {
ctx, span := tracer.Start(ctx, "accesscontrol.acimpl.Evaluate")
defer span.End()
if a.features.IsEnabledGlobally(featuremgmt.FlagZanzana) {
return a.evaluateCompare(ctx, user, evaluator)
}
return a.evaluate(ctx, user, evaluator)
}
func (a *AccessControl) evaluate(ctx context.Context, user identity.Requester, evaluator accesscontrol.Evaluator) (bool, error) {
ctx, span := tracer.Start(ctx, "accesscontrol.acimpl.evaluate")
defer span.End()
timer := prometheus.NewTimer(metrics.MAccessEvaluationsSummary)
defer timer.ObserveDuration()
metrics.MAccessEvaluationCount.Inc()
if user == nil || user.IsNil() {
a.log.Warn("No entity set for access control evaluation")
return false, nil
}
// If the user is in no organization, then the evaluation must happen based on the user's global permissions
permissions := user.GetPermissions()
if user.GetOrgID() == accesscontrol.NoOrgID {
permissions = user.GetGlobalPermissions()
}
if len(permissions) == 0 {
a.debug(ctx, user, "No permissions set", evaluator)
return false, nil
}
a.debug(ctx, user, "Evaluating permissions", evaluator)
// Test evaluation without scope resolver first, this will prevent 403 for wildcard scopes when resource does not exist
if evaluator.Evaluate(permissions) {
return true, nil
}
resolvedEvaluator, err := evaluator.MutateScopes(ctx, a.resolvers.GetScopeAttributeMutator(user.GetOrgID()))
if err != nil {
if errors.Is(err, accesscontrol.ErrResolverNotFound) {
return false, nil
}
return false, err
}
a.debug(ctx, user, "Evaluating resolved permissions", resolvedEvaluator)
return resolvedEvaluator.Evaluate(permissions), nil
}
func (a *AccessControl) evaluateZanzana(ctx context.Context, user identity.Requester, evaluator accesscontrol.Evaluator) (bool, error) {
ctx, span := tracer.Start(ctx, "accesscontrol.acimpl.evaluateZanzana")
defer span.End()
eval, err := evaluator.MutateScopes(ctx, a.resolvers.GetScopeAttributeMutator(user.GetOrgID()))
if err != nil {
if !errors.Is(err, accesscontrol.ErrResolverNotFound) {
return false, err
}
eval = evaluator
}
return eval.EvaluateCustom(func(action, scope string) (bool, error) {
kind, _, identifier := accesscontrol.SplitScope(scope)
tupleKey, ok := zanzana.TranslateToTuple(user.GetUID(), action, kind, identifier, user.GetOrgID())
if !ok {
// unsupported translation
return false, errAccessNotImplemented
}
a.log.Debug("evaluating zanzana", "user", tupleKey.User, "relation", tupleKey.Relation, "object", tupleKey.Object)
allowed, err := a.Check(ctx, accesscontrol.CheckRequest{
// Namespace: claims.OrgNamespaceFormatter(user.GetOrgID()),
User: tupleKey.User,
Relation: tupleKey.Relation,
Object: tupleKey.Object,
})
if err != nil {
return false, err
}
return allowed, nil
})
}
type evalResult struct {
runner string
decision bool
err error
duration time.Duration
}
// evaluateCompare run RBAC and zanzana checks in parallel and then compare result
func (a *AccessControl) evaluateCompare(ctx context.Context, user identity.Requester, evaluator accesscontrol.Evaluator) (bool, error) {
ctx, span := tracer.Start(ctx, "accesscontrol.acimpl.evaluateCompare")
defer span.End()
res := make(chan evalResult, 2)
go func() {
timer := prometheus.NewTimer(a.metrics.mAccessEngineEvaluationsSeconds.WithLabelValues("zanzana"))
defer timer.ObserveDuration()
start := time.Now()
hasAccess, err := a.evaluateZanzana(ctx, user, evaluator)
res <- evalResult{"zanzana", hasAccess, err, time.Since(start)}
}()
go func() {
timer := prometheus.NewTimer(a.metrics.mAccessEngineEvaluationsSeconds.WithLabelValues("grafana"))
defer timer.ObserveDuration()
start := time.Now()
hasAccess, err := a.evaluate(ctx, user, evaluator)
res <- evalResult{"grafana", hasAccess, err, time.Since(start)}
}()
first, second := <-res, <-res
close(res)
if second.runner == "grafana" {
first, second = second, first
}
if !errors.Is(second.err, errAccessNotImplemented) {
if second.err != nil {
a.log.Error("zanzana evaluation failed", "error", second.err)
} else if first.decision != second.decision {
a.metrics.mZanzanaEvaluationStatusTotal.WithLabelValues("error").Inc()
a.log.Warn(
"zanzana evaluation result does not match grafana",
"grafana_decision", first.decision,
"zanana_decision", second.decision,
"grafana_ms", first.duration,
"zanzana_ms", second.duration,
"eval", evaluator.GoString(),
)
} else {
a.metrics.mZanzanaEvaluationStatusTotal.WithLabelValues("success").Inc()
a.log.Debug("zanzana evaluation is correct", "grafana_ms", first.duration, "zanzana_ms", second.duration)
}
}
return first.decision, first.err
}
func (a *AccessControl) RegisterScopeAttributeResolver(prefix string, resolver accesscontrol.ScopeAttributeResolver) {
a.resolvers.AddScopeAttributeResolver(prefix, resolver)
}
func (a *AccessControl) WithoutResolvers() accesscontrol.AccessControl {
return &AccessControl{
features: a.features,
log: a.log,
zclient: a.zclient,
metrics: a.metrics,
resolvers: accesscontrol.NewResolvers(a.log),
}
}
func (a *AccessControl) debug(ctx context.Context, ident identity.Requester, msg string, eval accesscontrol.Evaluator) {
ctx, span := tracer.Start(ctx, "accesscontrol.acimpl.debug")
defer span.End()
a.log.FromContext(ctx).Debug(msg, "id", ident.GetID(), "orgID", ident.GetOrgID(), "permissions", eval.GoString())
}
func (a *AccessControl) Check(ctx context.Context, req accesscontrol.CheckRequest) (bool, error) {
key := &openfgav1.CheckRequestTupleKey{
User: req.User,
Relation: req.Relation,
Object: req.Object,
}
in := &openfgav1.CheckRequest{
TupleKey: key,
}
// Check direct access to resource first
res, err := a.zclient.CheckObject(ctx, in)
if err != nil {
return false, err
}
// no need to check folder access
if res.Allowed || req.Parent == "" {
return res.Allowed, nil
}
// Check access through the parent folder
ns, err := claims.ParseNamespace(req.Namespace)
if err != nil {
return false, err
}
folderKey := &openfgav1.CheckRequestTupleKey{
User: req.User,
Relation: zanzana.TranslateToFolderRelation(req.Relation, req.ObjectType),
Object: zanzana.NewScopedTupleEntry(zanzana.TypeFolder, req.Parent, "", strconv.FormatInt(ns.OrgID, 10)),
}
folderReq := &openfgav1.CheckRequest{
TupleKey: folderKey,
}
folderRes, err := a.zclient.CheckObject(ctx, folderReq)
if err != nil {
return false, err
}
return folderRes.Allowed, nil
}
func (a *AccessControl) ListObjects(ctx context.Context, req accesscontrol.ListObjectsRequest) ([]string, error) {
in := &openfgav1.ListObjectsRequest{
Type: req.Type,
User: req.User,
Relation: req.Relation,
}
res, err := a.zclient.ListObjects(ctx, in)
if err != nil {
return nil, err
}
return res.Objects, err
}