Chore: Use x/xerrors instead of pkg/errors (#16668)

* Use xerrors instead of pkg/errors

* Add Wrap util func

* Move Wrap to errutil package

pkg/services/dashboards/dashboard_service.go

@@ -9,7 +9,7 @@ import (
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/services/guardian"
 	"github.com/grafana/grafana/pkg/util"
-	"github.com/pkg/errors"
+	"github.com/grafana/grafana/pkg/util/errutil"
 )
 
 // DashboardService service for operating on dashboards
@@ -261,7 +261,7 @@ func (dr *dashboardServiceImpl) deleteDashboard(dashboardId int64, orgId int64,
 		isDashboardProvisioned := &models.IsDashboardProvisionedQuery{DashboardId: dashboardId}
 		err := bus.Dispatch(isDashboardProvisioned)
 		if err != nil {
-			return errors.Wrap(err, "error while checking if dashboard is provisioned")
+			return errutil.Wrap("failed to check if dashboard is provisioned", err)
 		}
 
 		if isDashboardProvisioned.Result {

pkg/services/dashboards/dashboard_service_test.go

@@ -6,9 +6,8 @@ import (
 	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/services/guardian"
-	"github.com/pkg/errors"
-
 	. "github.com/smartystreets/goconvey/convey"
+	"golang.org/x/xerrors"
 )
 
 func TestDashboardService(t *testing.T) {
@@ -116,7 +115,7 @@ func TestDashboardService(t *testing.T) {
 				})
 
 				bus.AddHandler("test", func(cmd *models.ValidateDashboardAlertsCommand) error {
-					return errors.New("Alert validation error")
+					return xerrors.New("Alert validation error")
 				})
 
 				dto.Dashboard = models.NewDashboard("Dash")

pkg/util/errutil/errors.go

@@ -0,0 +1,11 @@
+package errutil
+
+import "golang.org/x/xerrors"
+
+// Wrap is a simple wrapper around Errorf that is doing error wrapping. You can read how that works in
+// https://godoc.org/golang.org/x/xerrors#Errorf but its API is very implicit which is a reason for this wrapper.
+// There is also a discussion (https://github.com/golang/go/issues/29934) where many comments make arguments for such
+// wrapper so hopefully it will be added in the standard lib later.
+func Wrap(message string, err error) error {
+	return xerrors.Errorf("%v: %w", message, err)
+}