syntax = "proto3";

package envoy.api.v2;

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

import "google/protobuf/duration.proto";

import "validate/validate.proto";
import "gogoproto/gogo.proto";

// [#protodoc-title: Configuration sources]

// API configuration source. This identifies the API type and cluster that Envoy
// will use to fetch an xDS API.
message ApiConfigSource {
  // APIs may be fetched via either REST or gRPC.
  enum ApiType {
    // REST-JSON legacy corresponds to the v1 API.
    REST_LEGACY = 0;
    // REST-JSON v2 API. The `canonical JSON encoding
    // <https://developers.google.com/protocol-buffers/docs/proto3#json>`_ for
    // the v2 protos is used.
    REST = 1;
    // gRPC v2 API.
    GRPC = 2;
  }
  ApiType api_type = 1 [(validate.rules).enum.defined_only = true];
  // Multiple cluster names may be provided for REST_LEGACY/REST. If > 1
  // cluster is defined, clusters will be cycled through if any kind of failure
  // occurs.
  //
  // .. note::
  //
  //  The cluster with name ``cluster_name`` must be statically defined and its
  //  type must not be ``EDS``.
  repeated string cluster_names = 2;

  // Multiple gRPC services be provided for GRPC. If > 1 cluster is defined,
  // services will be cycled through if any kind of failure occurs.
  //
  // .. note::
  //
  //  If a gRPC service points to a ``cluster_name``, it must be statically
  //  defined and its type must not be ``EDS``.
  repeated GrpcService grpc_services = 4;

  // For REST APIs, the delay between successive polls.
  google.protobuf.Duration refresh_delay = 3 [(gogoproto.stdduration) = true];
}

// Aggregated Discovery Service (ADS) options. This is currently empty, but when
// set in :ref:`ConfigSource <envoy_api_msg_ConfigSource>` can be used to
// specify that ADS is to be used.
message AggregatedConfigSource {
}

// Configuration for :ref:`listeners <config_listeners>`, :ref:`clusters
// <config_cluster_manager_cluster>`, :ref:`routes
// <config_http_conn_man_route_table>`, :ref:`endpoints
// <arch_overview_service_discovery>` etc. may either be sourced from the
// filesystem or from an xDS API source. Filesystem configs are watched with
// inotify for updates.
message ConfigSource {
  oneof config_source_specifier {
    option (validate.required) = true;
    // Path on the filesystem to source and watch for configuration updates.
    //
    // .. note::
    //
    //  The path to the source must exist at config load time.
    //
    // .. note::
    //
    //   Envoy will only watch the file path for *moves.* This is because in general only moves
    //   are atomic. The same method of swapping files as is demonstrated in the
    //   :ref:`runtime documentation <config_runtime_symbolic_link_swap>` can be used here also.
    string path = 1;
    // API configuration source.
    ApiConfigSource api_config_source = 2;
    // When set, ADS will be used to fetch resources. The ADS API configuration
    // source in the bootstrap configuration is used.
    AggregatedConfigSource ads = 3;
  }
}