1syntax = "proto3";
2
3package envoy.service.discovery.v2;
4
5import "envoy/api/v2/core/base.proto";
6import "envoy/api/v2/core/health_check.proto";
7import "envoy/api/v2/endpoint/endpoint_components.proto";
8
9import "google/api/annotations.proto";
10import "google/protobuf/duration.proto";
11
12import "udpa/annotations/migrate.proto";
13import "udpa/annotations/status.proto";
14
15option java_package = "io.envoyproxy.envoy.service.discovery.v2";
16option java_outer_classname = "HdsProto";
17option java_multiple_files = true;
18option go_package = "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v2;discoveryv2";
19option java_generic_services = true;
20option (udpa.annotations.file_migrate).move_to_package = "envoy.service.health.v3";
21option (udpa.annotations.file_status).package_version_status = FROZEN;
22
23// [#protodoc-title: Health Discovery Service (HDS)]
24
25// HDS is Health Discovery Service. It compliments Envoy’s health checking
26// service by designating this Envoy to be a healthchecker for a subset of hosts
27// in the cluster. The status of these health checks will be reported to the
28// management server, where it can be aggregated etc and redistributed back to
29// Envoy through EDS.
30service HealthDiscoveryService {
31 // 1. Envoy starts up and if its can_healthcheck option in the static
32 // bootstrap config is enabled, sends HealthCheckRequest to the management
33 // server. It supplies its capabilities (which protocol it can health check
34 // with, what zone it resides in, etc.).
35 // 2. In response to (1), the management server designates this Envoy as a
36 // healthchecker to health check a subset of all upstream hosts for a given
37 // cluster (for example upstream Host 1 and Host 2). It streams
38 // HealthCheckSpecifier messages with cluster related configuration for all
39 // clusters this Envoy is designated to health check. Subsequent
40 // HealthCheckSpecifier message will be sent on changes to:
41 // a. Endpoints to health checks
42 // b. Per cluster configuration change
43 // 3. Envoy creates a health probe based on the HealthCheck config and sends
44 // it to endpoint(ip:port) of Host 1 and 2. Based on the HealthCheck
45 // configuration Envoy waits upon the arrival of the probe response and
46 // looks at the content of the response to decide whether the endpoint is
47 // healthy or not. If a response hasn't been received within the timeout
48 // interval, the endpoint health status is considered TIMEOUT.
49 // 4. Envoy reports results back in an EndpointHealthResponse message.
50 // Envoy streams responses as often as the interval configured by the
51 // management server in HealthCheckSpecifier.
52 // 5. The management Server collects health statuses for all endpoints in the
53 // cluster (for all clusters) and uses this information to construct
54 // EndpointDiscoveryResponse messages.
55 // 6. Once Envoy has a list of upstream endpoints to send traffic to, it load
56 // balances traffic to them without additional health checking. It may
57 // use inline healthcheck (i.e. consider endpoint UNHEALTHY if connection
58 // failed to a particular endpoint to account for health status propagation
59 // delay between HDS and EDS).
60 // By default, can_healthcheck is true. If can_healthcheck is false, Cluster
61 // configuration may not contain HealthCheck message.
62 // TODO(htuch): How is can_healthcheck communicated to CDS to ensure the above
63 // invariant?
64 // TODO(htuch): Add @amb67's diagram.
65 rpc StreamHealthCheck(stream HealthCheckRequestOrEndpointHealthResponse)
66 returns (stream HealthCheckSpecifier) {
67 }
68
69 // TODO(htuch): Unlike the gRPC version, there is no stream-based binding of
70 // request/response. Should we add an identifier to the HealthCheckSpecifier
71 // to bind with the response?
72 rpc FetchHealthCheck(HealthCheckRequestOrEndpointHealthResponse) returns (HealthCheckSpecifier) {
73 option (google.api.http).post = "/v2/discovery:health_check";
74 option (google.api.http).body = "*";
75 }
76}
77
78// Defines supported protocols etc, so the management server can assign proper
79// endpoints to healthcheck.
80message Capability {
81 // Different Envoy instances may have different capabilities (e.g. Redis)
82 // and/or have ports enabled for different protocols.
83 enum Protocol {
84 HTTP = 0;
85 TCP = 1;
86 REDIS = 2;
87 }
88
89 repeated Protocol health_check_protocols = 1;
90}
91
92message HealthCheckRequest {
93 api.v2.core.Node node = 1;
94
95 Capability capability = 2;
96}
97
98message EndpointHealth {
99 api.v2.endpoint.Endpoint endpoint = 1;
100
101 api.v2.core.HealthStatus health_status = 2;
102}
103
104message EndpointHealthResponse {
105 repeated EndpointHealth endpoints_health = 1;
106}
107
108message HealthCheckRequestOrEndpointHealthResponse {
109 oneof request_type {
110 HealthCheckRequest health_check_request = 1;
111
112 EndpointHealthResponse endpoint_health_response = 2;
113 }
114}
115
116message LocalityEndpoints {
117 api.v2.core.Locality locality = 1;
118
119 repeated api.v2.endpoint.Endpoint endpoints = 2;
120}
121
122// The cluster name and locality is provided to Envoy for the endpoints that it
123// health checks to support statistics reporting, logging and debugging by the
124// Envoy instance (outside of HDS). For maximum usefulness, it should match the
125// same cluster structure as that provided by EDS.
126message ClusterHealthCheck {
127 string cluster_name = 1;
128
129 repeated api.v2.core.HealthCheck health_checks = 2;
130
131 repeated LocalityEndpoints locality_endpoints = 3;
132}
133
134message HealthCheckSpecifier {
135 repeated ClusterHealthCheck cluster_health_checks = 1;
136
137 // The default is 1 second.
138 google.protobuf.Duration interval = 2;
139}
View as plain text