*: log at debug level when context is canceled

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

dispatch/dispatch.go

@@ -174,7 +174,14 @@ func (d *Dispatcher) processAlert(alert *types.Alert, route *Route) {
 		go ag.run(func(ctx context.Context, alerts ...*types.Alert) bool {
 			_, _, err := d.stage.Exec(ctx, d.logger, alerts...)
 			if err != nil {
-				level.Error(d.logger).Log("msg", "Notify for alerts failed", "num_alerts", len(alerts), "err", err)
+				lvl := level.Error(d.logger)
+				if ctx.Err() == context.Canceled {
+					// It is expected for the context to be canceled on
+					// configuration reload or shutdown. In this case, the
+					// message should only be logged at the debug level.
+					lvl = level.Debug(d.logger)
+				}
+				lvl.Log("msg", "Notify for alerts failed", "num_alerts", len(alerts), "err", err)
 			}
 			return err == nil
 		})

notify/notify.go

@@ -329,7 +329,14 @@ func (fs FanoutStage) Exec(ctx context.Context, l log.Logger, alerts ...*types.A
 		go func(s Stage) {
 			if _, _, err := s.Exec(ctx, l, alerts...); err != nil {
 				me.Add(err)
-				level.Error(l).Log("msg", "Error on notify", "err", err)
+				lvl := level.Error(l)
+				if ctx.Err() == context.Canceled {
+					// It is expected for the context to be canceled on
+					// configuration reload or shutdown. In this case, the
+					// message should only be logged at the debug level.
+					lvl = level.Debug(l)
+				}
+				lvl.Log("msg", "Error on notify", "err", err)
 			}
 			wg.Done()
 		}(s)