// [#protodoc-title: Tracing]
// Tracing :ref:`architecture overview <arch_overview_tracing>`.

syntax = "proto3";

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

import "envoy/api/v2/grpc_service.proto";

import "google/protobuf/struct.proto";

import "validate/validate.proto";

// The tracing configuration specifies global
// settings for the HTTP tracer used by Envoy. The configuration is defined by
// the :ref:`Bootstrap <envoy_api_msg_config.bootstrap.v2.Bootstrap>` :ref:`tracing
// <envoy_api_field_config.bootstrap.v2.Bootstrap.tracing>` field. Envoy may support other tracers
// in the future, but right now the HTTP tracer is the only one supported.
message Tracing {
  message Http {
    // The name of the HTTP trace driver to instantiate. The name must match a
    // supported HTTP trace driver. *envoy.lightstep*, *envoy.zipkin*, and
    // *envoy.dynamic.ot* are built-in trace drivers.
    string name = 1 [(validate.rules).string.min_bytes = 1];

    // Trace driver specific configuration which depends on the driver being
    // instantiated. See the :ref:`LightstepConfig
    // <envoy_api_msg_config.trace.v2.LightstepConfig>`, :ref:`ZipkinConfig
    // <envoy_api_msg_config.trace.v2.ZipkinConfig>`, and :ref:`DynamicOtConfig
    // <envoy_api_msg_config.trace.v2.DynamicOtConfig>` trace drivers for examples.
    google.protobuf.Struct config = 2;
  }
  // Provides configuration for the HTTP tracer.
  Http http = 1;
}

// Configuration for the LightStep tracer.
message LightstepConfig {
  // The cluster manager cluster that hosts the LightStep collectors.
  string collector_cluster = 1 [(validate.rules).string.min_bytes = 1];

  // File containing the access token to the `LightStep
  // <http://lightstep.com/>`_ API.
  string access_token_file = 2 [(validate.rules).string.min_bytes = 1];
}

message ZipkinConfig {
  // The cluster manager cluster that hosts the Zipkin collectors. Note that the
  // Zipkin cluster must be defined in the :ref:`Bootstrap static cluster
  // resources <envoy_api_field_config.bootstrap.v2.Bootstrap.StaticResources.clusters>`.
  string collector_cluster = 1 [(validate.rules).string.min_bytes = 1];

  // The API endpoint of the Zipkin service where the spans will be sent. When
  // using a standard Zipkin installation, the API endpoint is typically
  // /api/v1/spans, which is the default value.
  string collector_endpoint = 2 [(validate.rules).string.min_bytes = 1];
}

// DynamicOtConfig is used to dynamically load a tracer from a shared library
// that implements the `OpenTracing dynamic loading API
// <https://github.com/opentracing/opentracing-cpp>`_.
message DynamicOtConfig {
  // Dynamic library implementing the `OpenTracing API
  // <https://github.com/opentracing/opentracing-cpp>`_.
  string library = 1 [(validate.rules).string.min_bytes = 1];

  // The configuration to use when creating a tracer from the given dynamic
  // library.
  google.protobuf.Struct config = 2;
}

// Configuration structure.
message TraceServiceConfig {
  // The upstream gRPC cluster that hosts the metrics service.
  envoy.api.v2.GrpcService grpc_service = 1 [(validate.rules).message.required = true];
}