open-consul/proto/pbsubscribe/subscribe.proto

133 lines
5.5 KiB
Protocol Buffer

/*
Package event provides a service for subscribing to state change events.
*/
syntax = "proto3";
package subscribe;
option go_package = "github.com/hashicorp/consul/proto/pbsubscribe";
import "proto/pbservice/node.proto";
// StateChangeSubscription service allows consumers to subscribe to topics of
// state change events. Events are streamed as they happen.
service StateChangeSubscription {
// Subscribe to a topic to receive events when there are changes to the topic.
//
// If SubscribeRequest.Index is 0 the event stream will start with one or
// more snapshot events, followed by an EndOfSnapshot event. Subsequent
// events will be a live stream of events as they happen.
//
// If SubscribeRequest.Index is > 0 it is assumed the client already has a
// snapshot, and is trying to resume a stream that was disconnected. The
// client will either receive a NewSnapshotToFollow event, indicating the
// client view is stale and it must reset its view and prepare for a new
// snapshot. Or, if no NewSnapshotToFollow event is received, the client
// view is still fresh, and all events will be the live stream.
//
// Subscribe may return a gRPC status error with codes.ABORTED to indicate
// the client view is now stale due to a change on the server. The client
// must reset its view and issue a new Subscribe call to restart the stream.
// This error is used when the server can no longer correctly maintain the
// stream, for example because the ACL permissions for the token changed, or
// because the server state was restored from a snapshot.
rpc Subscribe(SubscribeRequest) returns (stream Event) {}
}
// Topic enumerates the supported event topics.
enum Topic {
Unknown = 0;
// ServiceHealth topic contains events for any changes to service health.
ServiceHealth = 1;
// ServiceHealthConnect topic contains events for any changes to service
// health for connect-enabled services.
ServiceHealthConnect = 2;
}
// SubscribeRequest used to subscribe to a topic.
message SubscribeRequest {
// Topic identifies the set of events the subscriber is interested in.
Topic Topic = 1;
// Key is a topic-specific identifier that restricts the scope of the
// subscription to only events pertaining to that identifier. For example,
// to receive events for a single service, the service's name is
// specified as the key. An empty key indicates that all events in the topic
// are of interest.
string Key = 2;
// Token is the ACL token to authenticate the request. The token must have
// sufficient privileges to read the requested information otherwise events
// will be filtered, possibly resulting in an empty snapshot and no further
// updates sent.
string Token = 3;
// Index is the raft index the subscriber has already observed up to. This
// is zero on an initial streaming call, but then can be provided by a
// client on subsequent re-connections such that the full snapshot doesn't
// need to be resent if the client is up to date.
uint64 Index = 4;
// Datacenter specifies the Consul datacenter the request is targeted at.
// If it's not the local DC the server will forward the request to
// the remote DC and proxy the results back to the subscriber. An empty
// string defaults to the local datacenter.
string Datacenter = 5;
// Namespace which contains the resources. If Namespace is not specified the
// default namespace will be used.
//
// Namespace is an enterprise-only feature.
string Namespace = 6;
}
// Event describes a streaming update on a subscription. Events are used both to
// describe the current "snapshot" of the result as well as ongoing mutations to
// that snapshot.
message Event {
// Index is the raft index at which the mutation took place. At the top
// level of a subscription there will always be at most one Event per index.
// If multiple events are published to the same topic in a single raft
// transaction then the batch of events will be encoded inside a single
// top-level event to ensure they are delivered atomically to clients.
uint64 Index = 1;
// Payload is the actual event content.
oneof Payload {
// EndOfSnapshot indicates the event stream for the initial snapshot has
// ended. Subsequent Events delivered will be mutations to that result.
bool EndOfSnapshot = 2;
// NewSnapshotToFollow indicates that the client view is stale. The client
// must reset its view before handing any more events. Subsequent events
// in the stream will be for a new snapshot until an EndOfSnapshot event
// is received.
bool NewSnapshotToFollow = 3;
// EventBatch is a set of events. This is typically used as the payload
// type where multiple events are emitted in a single topic and raft
// index (e.g. transactional updates). In this case the Topic and Index
// values of all events will match and the whole set should be delivered
// and consumed atomically.
EventBatch EventBatch = 4;
// ServiceHealth is used for ServiceHealth and ServiceHealthConnect
// topics.
ServiceHealthUpdate ServiceHealth = 10;
}
}
message EventBatch {
repeated Event Events = 1;
}
enum CatalogOp {
Register = 0;
Deregister = 1;
}
message ServiceHealthUpdate {
CatalogOp Op = 1;
pbservice.CheckServiceNode CheckServiceNode = 2;
}