- adding the error to the field labels

handlers.go

@@ -197,6 +197,7 @@ func (r *KeycloakProxy) authenticationHandler() gin.HandlerFunc {
 			fields := log.Fields{
 				"username":   userContext.name,
 				"expired_on": userContext.expiresAt.String(),
+				"error": err.Error(),
 			}
 
 			// step: if the error post verification is anything other than a token expired error