// 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.config.metrics.v3;

import "envoy/config/core/v3/address.proto";
import "envoy/type/matcher/v3/string.proto";

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

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

option java_package = "io.envoyproxy.envoy.config.metrics.v3";
option java_outer_classname = "StatsProto";
option java_multiple_files = true;
option go_package = "github.com/envoyproxy/go-control-plane/envoy/config/metrics/v3;metricsv3";
option (udpa.annotations.file_status).package_version_status = ACTIVE;

// [#protodoc-title: Stats]
// Statistics :ref:`architecture overview <arch_overview_statistics>`.

// Configuration for pluggable stats sinks.
message StatsSink {
  option (udpa.annotations.versioning).previous_message_type = "envoy.config.metrics.v2.StatsSink";

  reserved 2;

  reserved "config";

  // The name of the stats sink to instantiate. The name must match a supported
  // stats sink.
  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.stats_sinks>` for the default list of available stats sink.
  // Sinks optionally support tagged/multiple dimensional metrics.
  string name = 1;

  // Stats sink specific configuration which depends on the sink being instantiated. See
  // :ref:`StatsdSink <envoy_v3_api_msg_config.metrics.v3.StatsdSink>` for an example.
  // [#extension-category: envoy.stats_sinks]
  oneof config_type {
    google.protobuf.Any typed_config = 3;
  }
}

// Statistics configuration such as tagging.
message StatsConfig {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.metrics.v2.StatsConfig";

  // Each stat name is independently processed through these tag specifiers. When a tag is
  // matched, the first capture group is not immediately removed from the name, so later
  // :ref:`TagSpecifiers <envoy_v3_api_msg_config.metrics.v3.TagSpecifier>` can also match that
  // same portion of the match. After all tag matching is complete, a tag-extracted version of
  // the name is produced and is used in stats sinks that represent tags, such as Prometheus.
  repeated TagSpecifier stats_tags = 1;

  // Use all default tag regexes specified in Envoy. These can be combined with
  // custom tags specified in :ref:`stats_tags
  // <envoy_v3_api_field_config.metrics.v3.StatsConfig.stats_tags>`. They will be processed before
  // the custom tags.
  //
  // .. note::
  //
  //   If any default tags are specified twice, the config will be considered
  //   invalid.
  //
  // See :repo:`well_known_names.h <source/common/config/well_known_names.h>` for a list of the
  // default tags in Envoy.
  //
  // If not provided, the value is assumed to be true.
  google.protobuf.BoolValue use_all_default_tags = 2;

  // Inclusion/exclusion matcher for stat name creation. If not provided, all stats are instantiated
  // as normal. Preventing the instantiation of certain families of stats can improve memory
  // performance for Envoys running especially large configs.
  //
  // .. warning::
  //   Excluding stats may affect Envoy's behavior in undocumented ways. See
  //   `issue #8771 <https://github.com/envoyproxy/envoy/issues/8771>`_ for more information.
  //   If any unexpected behavior changes are observed, please open a new issue immediately.
  StatsMatcher stats_matcher = 3;

  // Defines rules for setting the histogram buckets. Rules are evaluated in order, and the first
  // match is applied. If no match is found (or if no rules are set), the following default buckets
  // are used:
  //
  //   .. code-block:: json
  //
  //     [
  //       0.5,
  //       1,
  //       5,
  //       10,
  //       25,
  //       50,
  //       100,
  //       250,
  //       500,
  //       1000,
  //       2500,
  //       5000,
  //       10000,
  //       30000,
  //       60000,
  //       300000,
  //       600000,
  //       1800000,
  //       3600000
  //     ]
  repeated HistogramBucketSettings histogram_bucket_settings = 4;
}

// Configuration for disabling stat instantiation.
message StatsMatcher {
  // The instantiation of stats is unrestricted by default. If the goal is to configure Envoy to
  // instantiate all stats, there is no need to construct a StatsMatcher.
  //
  // However, StatsMatcher can be used to limit the creation of families of stats in order to
  // conserve memory. Stats can either be disabled entirely, or they can be
  // limited by either an exclusion or an inclusion list of :ref:`StringMatcher
  // <envoy_v3_api_msg_type.matcher.v3.StringMatcher>` protos:
  //
  // * If ``reject_all`` is set to ``true``, no stats will be instantiated. If ``reject_all`` is set to
  //   ``false``, all stats will be instantiated.
  //
  // * If an exclusion list is supplied, any stat name matching *any* of the StringMatchers in the
  //   list will not instantiate.
  //
  // * If an inclusion list is supplied, no stats will instantiate, except those matching *any* of
  //   the StringMatchers in the list.
  //
  //
  // A StringMatcher can be used to match against an exact string, a suffix / prefix, or a regex.
  // **NB:** For performance reasons, it is highly recommended to use a prefix- or suffix-based
  // matcher rather than a regex-based matcher.
  //
  // Example 1. Excluding all stats.
  //
  // .. code-block:: json
  //
  //   {
  //     "statsMatcher": {
  //       "rejectAll": "true"
  //     }
  //   }
  //
  // Example 2. Excluding all cluster-specific stats, but not cluster-manager stats:
  //
  // .. code-block:: json
  //
  //   {
  //     "statsMatcher": {
  //       "exclusionList": {
  //         "patterns": [
  //           {
  //             "prefix": "cluster."
  //           }
  //         ]
  //       }
  //     }
  //   }
  //
  // Example 3. Including only manager-related stats:
  //
  // .. code-block:: json
  //
  //   {
  //     "statsMatcher": {
  //       "inclusionList": {
  //         "patterns": [
  //           {
  //             "prefix": "cluster_manager."
  //           },
  //           {
  //             "prefix": "listener_manager."
  //           }
  //         ]
  //       }
  //     }
  //   }
  //

  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.metrics.v2.StatsMatcher";

  oneof stats_matcher {
    option (validate.required) = true;

    // If ``reject_all`` is true, then all stats are disabled. If ``reject_all`` is false, then all
    // stats are enabled.
    bool reject_all = 1;

    // Exclusive match. All stats are enabled except for those matching one of the supplied
    // StringMatcher protos.
    type.matcher.v3.ListStringMatcher exclusion_list = 2;

    // Inclusive match. No stats are enabled except for those matching one of the supplied
    // StringMatcher protos.
    type.matcher.v3.ListStringMatcher inclusion_list = 3;
  }
}

// Designates a tag name and value pair. The value may be either a fixed value
// or a regex providing the value via capture groups. The specified tag will be
// unconditionally set if a fixed value, otherwise it will only be set if one
// or more capture groups in the regex match.
message TagSpecifier {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.metrics.v2.TagSpecifier";

  // Attaches an identifier to the tag values to identify the tag being in the
  // sink. Envoy has a set of default names and regexes to extract dynamic
  // portions of existing stats, which can be found in :repo:`well_known_names.h
  // <source/common/config/well_known_names.h>` in the Envoy repository. If a :ref:`tag_name
  // <envoy_v3_api_field_config.metrics.v3.TagSpecifier.tag_name>` is provided in the config and
  // neither :ref:`regex <envoy_v3_api_field_config.metrics.v3.TagSpecifier.regex>` or
  // :ref:`fixed_value <envoy_v3_api_field_config.metrics.v3.TagSpecifier.fixed_value>` were specified,
  // Envoy will attempt to find that name in its set of defaults and use the accompanying regex.
  //
  // .. note::
  //
  //   A stat name may be spelled in such a way that it matches two different
  //   tag extractors for the same tag name. In that case, all but one of the
  //   tag values will be dropped. It is not specified which tag value will be
  //   retained. The extraction will only occur for one of the extractors, and
  //   only the matched extraction will be removed from the tag name.
  string tag_name = 1;

  oneof tag_value {
    // Designates a tag to strip from the tag extracted name and provide as a named
    // tag value for all statistics. This will only occur if any part of the name
    // matches the regex provided with one or more capture groups.
    //
    // The first capture group identifies the portion of the name to remove. The
    // second capture group (which will normally be nested inside the first) will
    // designate the value of the tag for the statistic. If no second capture
    // group is provided, the first will also be used to set the value of the tag.
    // All other capture groups will be ignored.
    //
    // Example 1. a stat name ``cluster.foo_cluster.upstream_rq_timeout`` and
    // one tag specifier:
    //
    // .. code-block:: json
    //
    //   {
    //     "tag_name": "envoy.cluster_name",
    //     "regex": "^cluster\\.((.+?)\\.)"
    //   }
    //
    // Note that the regex will remove ``foo_cluster.`` making the tag extracted
    // name ``cluster.upstream_rq_timeout`` and the tag value for
    // ``envoy.cluster_name`` will be ``foo_cluster`` (note: there will be no
    // ``.`` character because of the second capture group).
    //
    // Example 2. a stat name
    // ``http.connection_manager_1.user_agent.ios.downstream_cx_total`` and two
    // tag specifiers:
    //
    // .. code-block:: json
    //
    //   [
    //     {
    //       "tag_name": "envoy.http_user_agent",
    //       "regex": "^http(?=\\.).*?\\.user_agent\\.((.+?)\\.)\\w+?$"
    //     },
    //     {
    //       "tag_name": "envoy.http_conn_manager_prefix",
    //       "regex": "^http\\.((.*?)\\.)"
    //     }
    //   ]
    //
    // The two regexes of the specifiers will be processed from the elaborated
    // stat name.
    //
    // The first regex will save ``ios.`` as the tag value for ``envoy.http_user_agent``. It will
    // leave it in the name for potential matching with additional tag specifiers. After all tag
    // specifiers are processed the tags will be removed from the name.
    //
    // The second regex will populate tag ``envoy.http_conn_manager_prefix`` with value
    // ``connection_manager_1.``, based on the original stat name.
    //
    // As a final step, the matched tags are removed, leaving
    // ``http.user_agent.downstream_cx_total`` as the tag extracted name.
    string regex = 2 [(validate.rules).string = {max_bytes: 1024}];

    // Specifies a fixed tag value for the ``tag_name``.
    string fixed_value = 3;
  }
}

// Specifies a matcher for stats and the buckets that matching stats should use.
message HistogramBucketSettings {
  // The stats that this rule applies to. The match is applied to the original stat name
  // before tag-extraction, for example ``cluster.exampleclustername.upstream_cx_length_ms``.
  type.matcher.v3.StringMatcher match = 1 [(validate.rules).message = {required: true}];

  // Each value is the upper bound of a bucket. Each bucket must be greater than 0 and unique.
  // The order of the buckets does not matter.
  repeated double buckets = 2 [(validate.rules).repeated = {
    min_items: 1
    unique: true
    items {double {gt: 0.0}}
  }];
}

// Stats configuration proto schema for built-in ``envoy.stat_sinks.statsd`` sink. This sink does not support
// tagged metrics.
// [#extension: envoy.stat_sinks.statsd]
message StatsdSink {
  option (udpa.annotations.versioning).previous_message_type = "envoy.config.metrics.v2.StatsdSink";

  oneof statsd_specifier {
    option (validate.required) = true;

    // The UDP address of a running `statsd <https://github.com/etsy/statsd>`_
    // compliant listener. If specified, statistics will be flushed to this
    // address.
    core.v3.Address address = 1;

    // The name of a cluster that is running a TCP `statsd
    // <https://github.com/etsy/statsd>`_ compliant listener. If specified,
    // Envoy will connect to this cluster to flush statistics.
    string tcp_cluster_name = 2;
  }

  // Optional custom prefix for StatsdSink. If
  // specified, this will override the default prefix.
  // For example:
  //
  // .. code-block:: json
  //
  //   {
  //     "prefix" : "envoy-prod"
  //   }
  //
  // will change emitted stats to
  //
  // .. code-block:: cpp
  //
  //   envoy-prod.test_counter:1|c
  //   envoy-prod.test_timer:5|ms
  //
  // Note that the default prefix, "envoy", will be used if a prefix is not
  // specified.
  //
  // Stats with default prefix:
  //
  // .. code-block:: cpp
  //
  //   envoy.test_counter:1|c
  //   envoy.test_timer:5|ms
  string prefix = 3;
}

// Stats configuration proto schema for built-in ``envoy.stat_sinks.dog_statsd`` sink.
// The sink emits stats with `DogStatsD <https://docs.datadoghq.com/guides/dogstatsd/>`_
// compatible tags. Tags are configurable via :ref:`StatsConfig
// <envoy_v3_api_msg_config.metrics.v3.StatsConfig>`.
// [#extension: envoy.stat_sinks.dog_statsd]
message DogStatsdSink {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.metrics.v2.DogStatsdSink";

  reserved 2;

  oneof dog_statsd_specifier {
    option (validate.required) = true;

    // The UDP address of a running DogStatsD compliant listener. If specified,
    // statistics will be flushed to this address.
    core.v3.Address address = 1;
  }

  // Optional custom metric name prefix. See :ref:`StatsdSink's prefix field
  // <envoy_v3_api_field_config.metrics.v3.StatsdSink.prefix>` for more details.
  string prefix = 3;

  // Optional max datagram size to use when sending UDP messages. By default Envoy
  // will emit one metric per datagram. By specifying a max-size larger than a single
  // metric, Envoy will emit multiple, new-line separated metrics. The max datagram
  // size should not exceed your network's MTU.
  //
  // Note that this value may not be respected if smaller than a single metric.
  google.protobuf.UInt64Value max_bytes_per_datagram = 4 [(validate.rules).uint64 = {gt: 0}];
}

// Stats configuration proto schema for built-in ``envoy.stat_sinks.hystrix`` sink.
// The sink emits stats in `text/event-stream
// <https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events>`_
// formatted stream for use by `Hystrix dashboard
// <https://github.com/Netflix-Skunkworks/hystrix-dashboard/wiki>`_.
//
// Note that only a single HystrixSink should be configured.
//
// Streaming is started through an admin endpoint :http:get:`/hystrix_event_stream`.
// [#extension: envoy.stat_sinks.hystrix]
message HystrixSink {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.metrics.v2.HystrixSink";

  // The number of buckets the rolling statistical window is divided into.
  //
  // Each time the sink is flushed, all relevant Envoy statistics are sampled and
  // added to the rolling window (removing the oldest samples in the window
  // in the process). The sink then outputs the aggregate statistics across the
  // current rolling window to the event stream(s).
  //
  // ``rolling_window(ms)`` = ``stats_flush_interval(ms)`` * ``num_of_buckets``
  //
  // More detailed explanation can be found in `Hystrix wiki
  // <https://github.com/Netflix/Hystrix/wiki/Metrics-and-Monitoring#hystrixrollingnumber>`_.
  int64 num_buckets = 1;
}
