// 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.filters.http.router.v3;

import "envoy/config/accesslog/v3/accesslog.proto";
import "envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto";

import "google/protobuf/duration.proto";
import "google/protobuf/wrappers.proto";

import "envoy/annotations/deprecation.proto";
import "udpa/annotations/status.proto";
import "udpa/annotations/versioning.proto";
import "validate/validate.proto";

option java_package = "io.envoyproxy.envoy.extensions.filters.http.router.v3";
option java_outer_classname = "RouterProto";
option java_multiple_files = true;
option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/http/router/v3;routerv3";
option (udpa.annotations.file_status).package_version_status = ACTIVE;

// [#protodoc-title: Router]
// Router :ref:`configuration overview <config_http_filters_router>`.
// [#extension: envoy.filters.http.router]

// [#next-free-field: 10]
message Router {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.filter.http.router.v2.Router";

  message UpstreamAccessLogOptions {
    // If set to true, an upstream access log will be recorded when an upstream stream is
    // associated to an http request. Note: Each HTTP request received for an already established
    // connection will result in an upstream access log record. This includes, for example,
    // consecutive HTTP requests over the same connection or a request that is retried.
    // In case a retry is applied, an upstream access log will be recorded for each retry.
    bool flush_upstream_log_on_upstream_stream = 1;

    // The interval to flush the upstream access logs. By default, the router will flush an upstream
    // access log on stream close, when the HTTP request is complete. If this field is set, the router
    // will flush access logs periodically at the specified interval. This is especially useful in the
    // case of long-lived requests, such as CONNECT and Websockets.
    // The interval must be at least 1 millisecond.
    google.protobuf.Duration upstream_log_flush_interval = 2
        [(validate.rules).duration = {gte {nanos: 1000000}}];
  }

  // Whether the router generates dynamic cluster statistics. Defaults to
  // true. Can be disabled in high performance scenarios.
  google.protobuf.BoolValue dynamic_stats = 1;

  // Whether to start a child span for egress routed calls. This can be
  // useful in scenarios where other filters (auth, ratelimit, etc.) make
  // outbound calls and have child spans rooted at the same ingress
  // parent. Defaults to false.
  //
  // .. attention::
  //   This field is deprecated by the
  //   :ref:`spawn_upstream_span <envoy_v3_api_field_extensions.filters.network.http_connection_manager.v3.HttpConnectionManager.Tracing.spawn_upstream_span>`.
  //   Please use that ``spawn_upstream_span`` field to control the span creation.
  bool start_child_span = 2
      [deprecated = true, (envoy.annotations.deprecated_at_minor_version) = "3.0"];

  // Configuration for HTTP upstream logs emitted by the router. Upstream logs
  // are configured in the same way as access logs, but each log entry represents
  // an upstream request. Presuming retries are configured, multiple upstream
  // requests may be made for each downstream (inbound) request.
  repeated config.accesslog.v3.AccessLog upstream_log = 3;

  // Additional upstream access log options.
  UpstreamAccessLogOptions upstream_log_options = 9;

  // Do not add any additional ``x-envoy-`` headers to requests or responses. This
  // only affects the :ref:`router filter generated x-envoy- headers
  // <config_http_filters_router_headers_set>`, other Envoy filters and the HTTP
  // connection manager may continue to set ``x-envoy-`` headers.
  bool suppress_envoy_headers = 4;

  // Specifies a list of HTTP headers to strictly validate. Envoy will reject a
  // request and respond with HTTP status 400 if the request contains an invalid
  // value for any of the headers listed in this field. Strict header checking
  // is only supported for the following headers:
  //
  // Value must be a ','-delimited list (i.e. no spaces) of supported retry
  // policy values:
  //
  // * :ref:`config_http_filters_router_x-envoy-retry-grpc-on`
  // * :ref:`config_http_filters_router_x-envoy-retry-on`
  //
  // Value must be an integer:
  //
  // * :ref:`config_http_filters_router_x-envoy-max-retries`
  // * :ref:`config_http_filters_router_x-envoy-upstream-rq-timeout-ms`
  // * :ref:`config_http_filters_router_x-envoy-upstream-rq-per-try-timeout-ms`
  repeated string strict_check_headers = 5 [(validate.rules).repeated = {
    items {
      string {
        in: "x-envoy-upstream-rq-timeout-ms"
        in: "x-envoy-upstream-rq-per-try-timeout-ms"
        in: "x-envoy-max-retries"
        in: "x-envoy-retry-grpc-on"
        in: "x-envoy-retry-on"
      }
    }
  }];

  // If not set, ingress Envoy will ignore
  // :ref:`config_http_filters_router_x-envoy-expected-rq-timeout-ms` header, populated by egress
  // Envoy, when deriving timeout for upstream cluster.
  bool respect_expected_rq_timeout = 6;

  // If set, Envoy will avoid incrementing HTTP failure code stats
  // on gRPC requests. This includes the individual status code value
  // (e.g. upstream_rq_504) and group stats (e.g. upstream_rq_5xx).
  // This field is useful if interested in relying only on the gRPC
  // stats filter to define success and failure metrics for gRPC requests
  // as not all failed gRPC requests charge HTTP status code metrics. See
  // :ref:`gRPC stats filter<config_http_filters_grpc_stats>` documentation
  // for more details.
  bool suppress_grpc_request_failure_code_stats = 7;

  // Optional HTTP filters for the upstream HTTP filter chain.
  //
  // .. note::
  //   Upstream HTTP filters are currently in alpha.
  //
  // These filters will be applied for all requests that pass through the router.
  // They will also be applied to shadowed requests.
  // Upstream HTTP filters cannot change route or cluster.
  // Upstream HTTP filters specified on the cluster will override these filters.
  //
  // If using upstream HTTP filters, please be aware that local errors sent by
  // upstream HTTP filters will not trigger retries, and local errors sent by
  // upstream HTTP filters will count as a final response if hedging is configured.
  // [#extension-category: envoy.filters.http.upstream]
  repeated network.http_connection_manager.v3.HttpFilter upstream_http_filters = 8;
}
