syntax = "proto3";

package registry;
option go_package = "github.com/pomerium/pomerium/pkg/grpc/registry";

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

enum ServiceKind {
  UNDEFINED_DO_NOT_USE = 0;

  // databroker grpc service
  DATABROKER = 1;
  // authorize grpc service
  AUTHORIZE = 2;
  // authentication http(s) service
  AUTHENTICATE = 3;
  // proxy service
  PROXY = 4;
  // registry service
  REGISTRY = 5;
  // console grpc service
  CONSOLE = 6;
  // prometheus metrics compatible http endpoint
  PROMETHEUS_METRICS = 7;
}

message Service {
  // kind is service kind
  ServiceKind kind = 1 [ (validate.rules).enum = {not_in : [ 0 ]} ];
  // network endpoints this service may be reachable at
  string endpoint = 3 [ (validate.rules).string.uri = true ];
}

message RegisterRequest {
  // services this deployment runs
  repeated Service services = 1 [ (validate.rules).repeated .min_items = 1 ];

  // service may optionally provide certain metadata, such as
  // - build version
  // - startup time
  // - bootstrap configuration
  // - OS, OS version, OS hostname
  // - etc
  // this information is not distributed back to the inquiring nodes
  // and may also have a different storage and time to live
  map<string, google.protobuf.Any> metadata = 2;
}

message RegisterResponse {
  // indicates when to report back again
  google.protobuf.Duration call_back_after = 2;
}

message ListRequest { repeated ServiceKind kinds = 1; }

message ServiceRegistration {
  Service service = 1;
  google.protobuf.Timestamp expires_at = 2;
}

// RegistrationSnapshot represents the current state of the services
message ServiceList { repeated Service services = 1; }

// Registry is invoked by services to inform
service Registry {
  // Report is periodically sent by each service to confirm it is still serving
  // with the registry data is persisted with a certain TTL
  rpc Report(RegisterRequest) returns (RegisterResponse);
  // List returns current snapshot of the services known to the registry
  rpc List(ListRequest) returns (ServiceList);
  // Watch returns a stream of updates
  // for the simplicity of consumer its delivered as full snapshots
  // and is only sent when change is detected
  rpc Watch(ListRequest) returns (stream ServiceList);
}