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

syntax = "proto3";

package envoy.config.metrics.v2;
option go_package = "v2";

import "envoy/api/v2/core/address.proto";

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

import "validate/validate.proto";

// Configuration for pluggable stats sinks.
message StatsSink {
  // The name of the stats sink to instantiate. The name must match a supported
  // stats sink. The built-in stats sinks are:
  //
  // * :ref:`envoy.statsd <envoy_api_msg_config.metrics.v2.StatsdSink>`
  // * :ref:`envoy.dog_statsd <envoy_api_msg_config.metrics.v2.DogStatsdSink>`
  // * :ref:`envoy.metrics_service <envoy_api_msg_config.metrics.v2.MetricsServiceConfig>`
  // * :ref:`envoy.stat_sinks.hystrix <envoy_api_msg_config.metrics.v2.HystrixSink>`
  //
  // 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_api_msg_config.metrics.v2.StatsdSink>` for an
  // example.
  google.protobuf.Struct config = 2;
}

// Statistics configuration such as tagging.
message StatsConfig {
  // Each stat name is iteratively processed through these tag specifiers.
  // When a tag is matched, the first capture group is removed from the name so
  // later :ref:`TagSpecifiers <envoy_api_msg_config.metrics.v2.TagSpecifier>` cannot match that
  // same portion of the match.
  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_api_field_config.metrics.v2.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 `well_known_names.h
  // <https://github.com/envoyproxy/envoy/blob/master/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;
}

// 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 {
  // 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 `well_known_names.h
  // <https://github.com/envoyproxy/envoy/blob/master/source/common/config/well_known_names.h>`_
  // in the Envoy repository. If a :ref:`tag_name
  // <envoy_api_field_config.metrics.v2.TagSpecifier.tag_name>` is provided in the config and
  // neither :ref:`regex <envoy_api_field_config.metrics.v2.TagSpecifier.regex>` or
  // :ref:`fixed_value <envoy_api_field_config.metrics.v2.TagSpecifier.fixed_value>` were specified,
  // Envoy will attempt to find that name in its set of defaults and use the accompanying regex.
  //
  // .. note::
  //
  //   It is invalid to specify the same tag name twice in a config.
  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 in the definition order.
    //
    // The first regex will remove ``ios.``, leaving the tag extracted name
    // ``http.connection_manager_1.user_agent.downstream_cx_total``. The tag
    // ``envoy.http_user_agent`` will be added with tag value ``ios``.
    //
    // The second regex will remove ``connection_manager_1.`` from the tag
    // extracted name produced by the first regex
    // ``http.connection_manager_1.user_agent.downstream_cx_total``, leaving
    // ``http.user_agent.downstream_cx_total`` as the tag extracted name. The tag
    // ``envoy.http_conn_manager_prefix`` will be added with the tag value
    // ``connection_manager_1``.
    string regex = 2 [(validate.rules).string.max_bytes = 1024];

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

// Stats configuration proto schema for built-in *envoy.statsd* sink. This sink does not support
// tagged metrics.
message 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.
    envoy.api.v2.core.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.dog_statsd* sink.
// The sink emits stats with `DogStatsD <https://docs.datadoghq.com/guides/dogstatsd/>`_
// compatible tags. Tags are configurable via :ref:`StatsConfig
// <envoy_api_msg_config.metrics.v2.StatsConfig>`.
// [#comment:next free field: 3]
message DogStatsdSink {
  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.
    envoy.api.v2.core.Address address = 1;
  }

  reserved 2;
}

// 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`.
message 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 `Hystix wiki
  // <https://github.com/Netflix/Hystrix/wiki/Metrics-and-Monitoring#hystrixrollingnumber>`_.
  int64 num_buckets = 1;
}