From 3d789d1f1656bbc353f15db07d3f0d794277c03b Mon Sep 17 00:00:00 2001
From: Airat Arifullin <a.arifullin@yadro.com>
Date: Mon, 16 Dec 2024 13:59:08 +0300
Subject: [PATCH] [#XX] ape: Introduce `ChainRouterError` error type

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>
---
 pkg/services/common/ape/checker.go |  2 +-
 pkg/services/common/ape/error.go   | 33 ++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 pkg/services/common/ape/error.go

diff --git a/pkg/services/common/ape/checker.go b/pkg/services/common/ape/checker.go
index 30580da12..b49a8c878 100644
--- a/pkg/services/common/ape/checker.go
+++ b/pkg/services/common/ape/checker.go
@@ -103,7 +103,7 @@ func (c *checkerCoreImpl) CheckAPE(prm CheckPrm) error {
 	if found && status == apechain.Allow {
 		return nil
 	}
-	return fmt.Errorf("access to operation %s is denied by access policy engine: %s", prm.Request.Operation(), status.String())
+	return NewChainRouterError(prm.Request.Operation(), status)
 }
 
 // isValidBearer checks whether bearer token was correctly signed by authorized
diff --git a/pkg/services/common/ape/error.go b/pkg/services/common/ape/error.go
new file mode 100644
index 000000000..0412441f6
--- /dev/null
+++ b/pkg/services/common/ape/error.go
@@ -0,0 +1,33 @@
+package ape
+
+import (
+	"fmt"
+
+	apechain "git.frostfs.info/TrueCloudLab/policy-engine/pkg/chain"
+)
+
+// ChainRouterError is returned when chain router validation prevents
+// the APE request from being processed (no rule found, access denied, etc.).
+type ChainRouterError struct {
+	operation string
+	status    apechain.Status
+}
+
+func (e *ChainRouterError) Error() string {
+	return fmt.Sprintf("access to operation %s is denied by access policy engine: %s", e.Operation(), e.Status().String())
+}
+
+func (e *ChainRouterError) Operation() string {
+	return e.operation
+}
+
+func (e *ChainRouterError) Status() apechain.Status {
+	return e.status
+}
+
+func NewChainRouterError(operation string, status apechain.Status) *ChainRouterError {
+	return &ChainRouterError{
+		operation: operation,
+		status:    status,
+	}
+}