[#919] ape: Improve error messages in ape service

* Wrap all APE middleware errors in apeErr that
  makes errors more explicit with status AccessDenied.
* Use denyingRuleErr for denying status from chain router.

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

pkg/services/object/ape/checker.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 
 	objectV2 "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
-	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 	apechain "git.frostfs.info/TrueCloudLab/policy-engine/pkg/chain"
@@ -70,13 +69,5 @@ func (c *checkerImpl) CheckAPE(ctx context.Context, prm Prm) error {
 		return nil
 	}
 
-	return apeErr(prm.Method, status)
+	return fmt.Errorf("found denying rule for %s: %s", prm.Method, status)
-}
-
-const accessDeniedAPEReasonFmt = "access to operation %s is denied by access policy engine: %s"
-
-func apeErr(op string, status apechain.Status) error {
-	errAccessDenied := &apistatus.ObjectAccessDenied{}
-	errAccessDenied.WriteReason(fmt.Sprintf(accessDeniedAPEReasonFmt, op, status.String()))
-	return errAccessDenied
 }

pkg/services/object/ape/checker_test.go

@@ -308,7 +308,8 @@ func TestAPECheck(t *testing.T) {
 					ms := inmemory.NewInmemoryMorphRuleChainStorage()
 
 					ls.AddOverride(chain.Ingress, policyengine.ContainerTarget(test.container), &chain.Chain{
-						Rules: test.containerRules,
+						Rules:     test.containerRules,
+						MatchType: chain.MatchTypeFirstMatch,
 					})
 
 					router := policyengine.NewDefaultChainRouterWithLocalOverrides(ms, ls)
@@ -336,8 +337,7 @@ func TestAPECheck(t *testing.T) {
 
 					err := checker.CheckAPE(context.Background(), prm)
 					if test.expectAPEErr {
-						aErr := apeErr(method, chain.AccessDenied)
+						require.Error(t, err)
-						require.ErrorAs(t, err, &aErr)
 					} else {
 						require.NoError(t, err)
 					}

pkg/services/object/ape/errors.go

@@ -0,0 +1,13 @@
+package ape
+
+import (
+	"fmt"
+
+	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
+)
+
+func toStatusErr(err error) error {
+	errAccessDenied := &apistatus.ObjectAccessDenied{}
+	errAccessDenied.WriteReason(fmt.Sprintf("ape denied request: %s", err.Error()))
+	return errAccessDenied
+}

pkg/services/object/ape/service.go

@@ -69,7 +69,7 @@ func (g *getStreamBasicChecker) Send(resp *objectV2.GetResponse) error {
 	if partInit, ok := resp.GetBody().GetObjectPart().(*objectV2.GetObjectPartInit); ok {
 		cnrID, objID, err := getAddressParamsSDK(partInit.GetHeader().GetContainerID(), partInit.GetObjectID())
 		if err != nil {
-			return err
+			return toStatusErr(err)
 		}
 
 		prm := Prm{
@@ -82,7 +82,7 @@ func (g *getStreamBasicChecker) Send(resp *objectV2.GetResponse) error {
 		}
 
 		if err := g.apeChecker.CheckAPE(g.Context(), prm); err != nil {
-			return err
+			return toStatusErr(err)
 		}
 	}
 	return g.GetObjectStream.Send(resp)
@@ -103,12 +103,12 @@ func requestContext(ctx context.Context) (*objectSvc.RequestContext, error) {
 func (c *Service) Get(request *objectV2.GetRequest, stream objectSvc.GetObjectStream) error {
 	cnrID, objID, err := getAddressParamsSDK(request.GetBody().GetAddress().GetContainerID(), request.GetBody().GetAddress().GetObjectID())
 	if err != nil {
-		return err
+		return toStatusErr(err)
 	}
 
 	reqCtx, err := requestContext(stream.Context())
 	if err != nil {
-		return err
+		return toStatusErr(err)
 	}
 
 	err = c.apeChecker.CheckAPE(stream.Context(), Prm{
@@ -120,7 +120,7 @@ func (c *Service) Get(request *objectV2.GetRequest, stream objectSvc.GetObjectSt
 		SenderKey: hex.EncodeToString(reqCtx.SenderKey),
 	})
 	if err != nil {
-		return err
+		return toStatusErr(err)
 	}
 
 	return c.next.Get(request, &getStreamBasicChecker{
@@ -139,12 +139,12 @@ func (p *putStreamBasicChecker) Send(ctx context.Context, request *objectV2.PutR
 	if partInit, ok := request.GetBody().GetObjectPart().(*objectV2.PutObjectPartInit); ok {
 		reqCtx, err := requestContext(ctx)
 		if err != nil {
-			return err
+			return toStatusErr(err)
 		}
 
 		cnrID, objID, err := getAddressParamsSDK(partInit.GetHeader().GetContainerID(), partInit.GetObjectID())
 		if err != nil {
-			return err
+			return toStatusErr(err)
 		}
 
 		prm := Prm{
@@ -158,7 +158,7 @@ func (p *putStreamBasicChecker) Send(ctx context.Context, request *objectV2.PutR
 		}
 
 		if err := p.apeChecker.CheckAPE(ctx, prm); err != nil {
-			return err
+			return toStatusErr(err)
 		}
 	}
 
@@ -244,13 +244,13 @@ func (c *Service) Search(request *objectV2.SearchRequest, stream objectSvc.Searc
 	var cnrID cid.ID
 	if cnrV2 := request.GetBody().GetContainerID(); cnrV2 != nil {
 		if err := cnrID.ReadFromV2(*cnrV2); err != nil {
-			return err
+			return toStatusErr(err)
 		}
 	}
 
 	reqCtx, err := requestContext(stream.Context())
 	if err != nil {
-		return err
+		return toStatusErr(err)
 	}
 
 	err = c.apeChecker.CheckAPE(stream.Context(), Prm{
@@ -261,7 +261,7 @@ func (c *Service) Search(request *objectV2.SearchRequest, stream objectSvc.Searc
 		SenderKey: hex.EncodeToString(reqCtx.SenderKey),
 	})
 	if err != nil {
-		return err
+		return toStatusErr(err)
 	}
 
 	return c.next.Search(request, stream)
@@ -301,12 +301,12 @@ func (c *Service) Delete(ctx context.Context, request *objectV2.DeleteRequest) (
 func (c *Service) GetRange(request *objectV2.GetRangeRequest, stream objectSvc.GetObjectRangeStream) error {
 	cnrID, objID, err := getAddressParamsSDK(request.GetBody().GetAddress().GetContainerID(), request.GetBody().GetAddress().GetObjectID())
 	if err != nil {
-		return err
+		return toStatusErr(err)
 	}
 
 	reqCtx, err := requestContext(stream.Context())
 	if err != nil {
-		return err
+		return toStatusErr(err)
 	}
 
 	err = c.apeChecker.CheckAPE(stream.Context(), Prm{
@@ -318,7 +318,7 @@ func (c *Service) GetRange(request *objectV2.GetRangeRequest, stream objectSvc.G
 		SenderKey: hex.EncodeToString(reqCtx.SenderKey),
 	})
 	if err != nil {
-		return err
+		return toStatusErr(err)
 	}
 
 	return c.next.GetRange(request, stream)
@@ -381,7 +381,7 @@ func (c *Service) PutSingle(ctx context.Context, request *objectV2.PutSingleRequ
 	}
 
 	if err = c.apeChecker.CheckAPE(ctx, prm); err != nil {
-		return nil, err
+		return nil, toStatusErr(err)
 	}
 
 	return c.next.PutSingle(ctx, request)