// 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.service.metrics.v3;

import "envoy/config/core/v3/base.proto";

import "io/prometheus/client/metrics.proto";

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

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

// [#protodoc-title: Metrics service]

// Service for streaming metrics to server that consumes the metrics data. It uses Prometheus metric
// data model as a standard to represent metrics information.
service MetricsService {
  // Envoy will connect and send StreamMetricsMessage messages forever. It does not expect any
  // response to be sent as nothing would be done in the case of failure.
  rpc StreamMetrics(stream StreamMetricsMessage) returns (StreamMetricsResponse) {
  }
}

message StreamMetricsResponse {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.service.metrics.v2.StreamMetricsResponse";
}

message StreamMetricsMessage {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.service.metrics.v2.StreamMetricsMessage";

  message Identifier {
    option (udpa.annotations.versioning).previous_message_type =
        "envoy.service.metrics.v2.StreamMetricsMessage.Identifier";

    // The node sending metrics over the stream.
    config.core.v3.Node node = 1 [(validate.rules).message = {required: true}];
  }

  // Identifier data effectively is a structured metadata. As a performance optimization this will
  // only be sent in the first message on the stream.
  Identifier identifier = 1;

  // A list of metric entries
  repeated io.prometheus.client.MetricFamily envoy_metrics = 2;
}
