Save response status to span.

fcm.go

@@ -28,6 +28,7 @@ import (
 	"golang.org/x/oauth2"
 
 	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
 )
 
 const tracerName = "git.bit5.ru/backend/fcm"
@@ -188,6 +189,10 @@ func (c *Client) doSendRequest(ctx context.Context, req SendRequest, loggerEnabl
 	}
 	defer response.Body.Close()
 
+	span.SetAttributes(
+		attribute.Int("response.status_code", response.StatusCode),
+	)
+
 	if response.StatusCode != http.StatusOK {
 		body, err := ioutil.ReadAll(response.Body)
 		if err != nil {