// Copyright 2020 The gRPC 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.

// Local copy of Envoy xDS proto file, used for testing only.

syntax = "proto3";

package envoy.service.discovery.v3;

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

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

message Status {
  // The status code, which should be an enum value of [google.rpc.Code][].
  int32 code = 1;

  // A developer-facing error message, which should be in English. Any
  // user-facing error message should be localized and sent in the
  // [google.rpc.Status.details][] field, or localized by the client.
  string message = 2;

  // A list of messages that carry the error details.  There is a common set of
  // message types for APIs to use.
  repeated google.protobuf.Any details = 3;
}

// [#protodoc-title: Common discovery API components]

// A DiscoveryRequest requests a set of versioned resources of the same type for
// a given Envoy node on some API.
// [#next-free-field: 7]
message DiscoveryRequest {
  // The version_info provided in the request messages will be the version_info
  // received with the most recent successfully processed response or empty on
  // the first request. It is expected that no new request is sent after a
  // response is received until the Envoy instance is ready to ACK/NACK the new
  // configuration. ACK/NACK takes place by returning the new API config version
  // as applied or the previous API config version respectively. Each type_url
  // (see below) has an independent version associated with it.
  string version_info = 1;

  // The node making the request.
  config.core.v3.Node node = 2;

  // List of resources to subscribe to, e.g. list of cluster names or a route
  // configuration name. If this is empty, all resources for the API are
  // returned. LDS/CDS may have empty resource_names, which will cause all
  // resources for the Envoy instance to be returned. The LDS and CDS responses
  // will then imply a number of resources that need to be fetched via EDS/RDS,
  // which will be explicitly enumerated in resource_names.
  repeated string resource_names = 3;

  // Type of the resource that is being requested, e.g.
  // "type.googleapis.com/envoy.api.v2.ClusterLoadAssignment". This is implicit
  // in requests made via singleton xDS APIs such as CDS, LDS, etc. but is
  // required for ADS.
  string type_url = 4;

  // nonce corresponding to DiscoveryResponse being ACK/NACKed. See above
  // discussion on version_info and the DiscoveryResponse nonce comment. This
  // may be empty only if 1) this is a non-persistent-stream xDS such as HTTP,
  // or 2) the client has not yet accepted an update in this xDS stream (unlike
  // delta, where it is populated only for new explicit ACKs).
  string response_nonce = 5;

  // This is populated when the previous :ref:`DiscoveryResponse <envoy_api_msg_service.discovery.v3.DiscoveryResponse>`
  // failed to update configuration. The *message* field in *error_details* provides the Envoy
  // internal exception related to the failure. It is only intended for consumption during manual
  // debugging, the string provided is not guaranteed to be stable across Envoy versions.
  Status error_detail = 6;
}

// [#next-free-field: 7]
message DiscoveryResponse {
  // The version of the response data.
  string version_info = 1;

  // The response resources. These resources are typed and depend on the API being called.
  repeated google.protobuf.Any resources = 2;

  // [#not-implemented-hide:]
  // Canary is used to support two Envoy command line flags:
  //
  // * --terminate-on-canary-transition-failure. When set, Envoy is able to
  //   terminate if it detects that configuration is stuck at canary. Consider
  //   this example sequence of updates:
  //   - Management server applies a canary config successfully.
  //   - Management server rolls back to a production config.
  //   - Envoy rejects the new production config.
  //   Since there is no sensible way to continue receiving configuration
  //   updates, Envoy will then terminate and apply production config from a
  //   clean slate.
  // * --dry-run-canary. When set, a canary response will never be applied, only
  //   validated via a dry run.
  bool canary = 3;

  // Type URL for resources. Identifies the xDS API when muxing over ADS.
  // Must be consistent with the type_url in the 'resources' repeated Any (if non-empty).
  string type_url = 4;

  // For gRPC based subscriptions, the nonce provides a way to explicitly ack a
  // specific DiscoveryResponse in a following DiscoveryRequest. Additional
  // messages may have been sent by Envoy to the management server for the
  // previous version on the stream prior to this DiscoveryResponse, that were
  // unprocessed at response send time. The nonce allows the management server
  // to ignore any further DiscoveryRequests for the previous version until a
  // DiscoveryRequest bearing the nonce. The nonce is optional and is not
  // required for non-stream based xDS implementations.
  string nonce = 5;
}

// [#next-free-field: 8]
message Resource {
  // Cache control properties for the resource.
  // [#not-implemented-hide:]
  message CacheControl {
    // If true, xDS proxies may not cache this resource.
    // Note that this does not apply to clients other than xDS proxies, which must cache resources
    // for their own use, regardless of the value of this field.
    bool do_not_cache = 1;
  }

  // The resource's name, to distinguish it from others of the same type of resource.
  string name = 3;

  // The aliases are a list of other names that this resource can go by.
  repeated string aliases = 4;

  // The resource level version. It allows xDS to track the state of individual
  // resources.
  string version = 1;

  // The resource being tracked.
  google.protobuf.Any resource = 2;

  // Time-to-live value for the resource. For each resource, a timer is started. The timer is
  // reset each time the resource is received with a new TTL. If the resource is received with
  // no TTL set, the timer is removed for the resource. Upon expiration of the timer, the
  // configuration for the resource will be removed.
  //
  // The TTL can be refreshed or changed by sending a response that doesn't change the resource
  // version. In this case the resource field does not need to be populated, which allows for
  // light-weight "heartbeat" updates to keep a resource with a TTL alive.
  //
  // The TTL feature is meant to support configurations that should be removed in the event of
  // a management server failure. For example, the feature may be used for fault injection
  // testing where the fault injection should be terminated in the event that Envoy loses contact
  // with the management server.
  google.protobuf.Duration ttl = 6;

  // Cache control properties for the resource.
  // [#not-implemented-hide:]
  CacheControl cache_control = 7;
}