From 9a4b2bdcccd94bfb5e67121f34a54fcd0eade458 Mon Sep 17 00:00:00 2001
From: Piotr Tabor <ptab@google.com>
Date: Thu, 22 Apr 2021 12:57:23 +0200
Subject: [PATCH] Errors: `context cancelled` or `context deadline exceeded`
 are exposed as codes.Canceled, codes.DeadlineExceeded instead of
 'codes.Unknown'

---
 CHANGELOG-3.5.md                    | 1 +
 api/v3rpc/rpctypes/error.go         | 3 +++
 server/etcdserver/api/v3rpc/util.go | 4 ++++
 tests/integration/clientv3/util.go  | 3 ++-
 4 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG-3.5.md b/CHANGELOG-3.5.md
index 81e825137..45db3a171 100644
--- a/CHANGELOG-3.5.md
+++ b/CHANGELOG-3.5.md
@@ -70,6 +70,7 @@ See [code changes](https://github.com/etcd-io/etcd/compare/v3.4.0...v3.5.0) and
 - [ETCD_CLIENT_DEBUG env](https://github.com/etcd-io/etcd/pull/12786): Now supports log levels (debug, info, warn, error, dpanic, panic, fatal). Only when set, overrides application-wide grpc logging settings.
 - [Embed Etcd.Close()](https://github.com/etcd-io/etcd/pull/12828) needs to called exactly once and closes Etcd.Err() stream.
 - [Embed Etcd does not override global/grpc logger](https://github.com/etcd-io/etcd/pull/12861) be default any longer. If desired, please call `embed.Config::SetupGlobalLoggers()` explicitly. 
+- Errors: `context cancelled` or `context deadline exceeded` are exposed as codes.Canceled, codes.DeadlineExceeded instead of 'codes.Unknown'.
 ###
 
 - Make sure [save snapshot downloads checksum for integrity checks](https://github.com/etcd-io/etcd/pull/11896).
diff --git a/api/v3rpc/rpctypes/error.go b/api/v3rpc/rpctypes/error.go
index 24fdc8573..c03e91cfb 100644
--- a/api/v3rpc/rpctypes/error.go
+++ b/api/v3rpc/rpctypes/error.go
@@ -84,6 +84,9 @@ var (
 	ErrGRPCDowngradeInProcess            = status.New(codes.FailedPrecondition, "etcdserver: cluster has a downgrade job in progress").Err()
 	ErrGRPCNoInflightDowngrade           = status.New(codes.FailedPrecondition, "etcdserver: no inflight downgrade job").Err()
 
+	ErrGRPCCanceled         = status.New(codes.Canceled, "etcdserver: request canceled").Err()
+	ErrGRPCDeadlineExceeded = status.New(codes.DeadlineExceeded, "etcdserver: context deadline exceeded").Err()
+
 	errStringToError = map[string]error{
 		ErrorDesc(ErrGRPCEmptyKey):      ErrGRPCEmptyKey,
 		ErrorDesc(ErrGRPCKeyNotFound):   ErrGRPCKeyNotFound,
diff --git a/server/etcdserver/api/v3rpc/util.go b/server/etcdserver/api/v3rpc/util.go
index dc6e0271f..51cbdc66a 100644
--- a/server/etcdserver/api/v3rpc/util.go
+++ b/server/etcdserver/api/v3rpc/util.go
@@ -83,6 +83,10 @@ var toGRPCErrorMap = map[error]error{
 	auth.ErrAuthNotEnabled:       rpctypes.ErrGRPCAuthNotEnabled,
 	auth.ErrInvalidAuthToken:     rpctypes.ErrGRPCInvalidAuthToken,
 	auth.ErrInvalidAuthMgmt:      rpctypes.ErrGRPCInvalidAuthMgmt,
+
+	// In sync with status.FromContextError
+	context.Canceled:         rpctypes.ErrGRPCCanceled,
+	context.DeadlineExceeded: rpctypes.ErrGRPCDeadlineExceeded,
 }
 
 func togRPCError(err error) error {
diff --git a/tests/integration/clientv3/util.go b/tests/integration/clientv3/util.go
index 674a5d1c8..26ee793c9 100644
--- a/tests/integration/clientv3/util.go
+++ b/tests/integration/clientv3/util.go
@@ -50,7 +50,8 @@ func IsServerCtxTimeout(err error) bool {
 		return false
 	}
 	code := ev.Code()
-	return code == codes.DeadlineExceeded && strings.Contains(err.Error(), "context deadline exceeded")
+	return (code == codes.DeadlineExceeded /*3.5+"*/ || code == codes.Unknown /*<=3.4*/) &&
+		strings.Contains(err.Error(), "context deadline exceeded")
 }
 
 // IsClientTimeout checks reason of the error.