// Copyright 2025 Envoy Project Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

syntax = "proto3";

package envoy.extensions.access_loggers.filters.cel.v3;

import "udpa/annotations/status.proto";

option java_package = "io.envoyproxy.envoy.extensions.access_loggers.filters.cel.v3";
option java_outer_classname = "CelProto";
option java_multiple_files = true;
option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/access_loggers/filters/cel/v3;celv3";
option (udpa.annotations.file_status).package_version_status = ACTIVE;

// [#protodoc-title: ExpressionFilter]
// [#extension: envoy.access_loggers.extension_filters.cel]

// ExpressionFilter is an access logging filter that evaluates configured
// symbolic Common Expression Language expressions to inform the decision
// to generate an access log.
message ExpressionFilter {
  // Expression that, when evaluated, will be used to filter access logs.
  // Expressions are based on the set of Envoy :ref:`attributes <arch_overview_attributes>`.
  // The provided expression must evaluate to true for logging (expression errors are considered false).
  // Examples:
  //
  // * ``response.code >= 400``
  // * ``(connection.mtls && request.headers['x-log-mtls'] == 'true') || request.url_path.contains('v1beta3')``
  string expression = 1;
}
