Merge pull request #1422 from unihorn/187

etcdserver: parse context error for better message

etcdserver/server.go

@@ -64,6 +64,8 @@ var (
 	ErrIDRemoved     = errors.New("etcdserver: ID removed")
 	ErrIDExists      = errors.New("etcdserver: ID exists")
 	ErrIDNotFound    = errors.New("etcdserver: ID not found")
+	ErrCanceled      = errors.New("etcdserver: request cancelled")
+	ErrTimeout       = errors.New("etcdserver: request timed out")
 
 	storeMembersPrefix        = path.Join(StoreAdminPrefix, "members")
 	storeRemovedMembersPrefix = path.Join(StoreAdminPrefix, "removed_members")
@@ -383,7 +385,7 @@ func (s *EtcdServer) Do(ctx context.Context, r pb.Request) (Response, error) {
 			return resp, resp.err
 		case <-ctx.Done():
 			s.w.Trigger(r.ID, nil) // GC wait
-			return Response{}, ctx.Err()
+			return Response{}, parseCtxErr(ctx.Err())
 		case <-s.done:
 			return Response{}, ErrStopped
 		}
@@ -477,7 +479,7 @@ func (s *EtcdServer) configure(ctx context.Context, cc raftpb.ConfChange) error
 		return nil
 	case <-ctx.Done():
 		s.w.Trigger(cc.ID, nil) // GC wait
-		return ctx.Err()
+		return parseCtxErr(ctx.Err())
 	case <-s.done:
 		return ErrStopped
 	}
@@ -752,6 +754,17 @@ func GenID() (n uint64) {
 	return
 }
 
+func parseCtxErr(err error) error {
+	switch err {
+	case context.Canceled:
+		return ErrCanceled
+	case context.DeadlineExceeded:
+		return ErrTimeout
+	default:
+		return err
+	}
+}
+
 func getBool(v *bool) (vv bool, set bool) {
 	if v == nil {
 		return false, false

etcdserver/server_test.go

@@ -614,8 +614,8 @@ func TestDoProposalCancelled(t *testing.T) {
 	if len(gaction) != 0 {
 		t.Errorf("len(action) = %v, want 0", len(gaction))
 	}
-	if err != context.Canceled {
-		t.Fatalf("err = %v, want %v", err, context.Canceled)
+	if err != ErrCanceled {
+		t.Fatalf("err = %v, want %v", err, ErrCanceled)
 	}
 	w := []action{action{name: "Register1"}, action{name: "Trigger1"}}
 	if !reflect.DeepEqual(wait.action, w) {
@@ -623,6 +623,18 @@ func TestDoProposalCancelled(t *testing.T) {
 	}
 }
 
+func TestDoProposalTimeout(t *testing.T) {
+	ctx, _ := context.WithTimeout(context.Background(), 0)
+	srv := &EtcdServer{
+		node: &nodeRecorder{},
+		w:    &waitRecorder{},
+	}
+	_, err := srv.Do(ctx, pb.Request{Method: "PUT", ID: 1})
+	if err != ErrTimeout {
+		t.Fatalf("err = %v, want %v", err, ErrTimeout)
+	}
+}
+
 func TestDoProposalStopped(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()