rtds: Runtime Discovery Service implementation. (#7251)

Fixes #6708.

Risk level: Low
Testing: Unit and integration tests added.

Signed-off-by: Harvey Tuch <htuch@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 07da3346bee84a7762052d9ce9f343a009ae994f

docs/BUILD

@@ -89,6 +89,7 @@ proto_library(
         "//envoy/service/auth/v2:attribute_context",
         "//envoy/service/auth/v2:external_auth",
         "//envoy/service/discovery/v2:ads",
+        "//envoy/service/discovery/v2:rtds",
         "//envoy/service/load_stats/v2:lrs",
         "//envoy/service/metrics/v2:metrics_service",
         "//envoy/service/ratelimit/v2:rls",

envoy/config/bootstrap/v2/bootstrap.proto

@@ -237,13 +237,6 @@ message Runtime {
 }
 
 message RuntimeLayer {
-  // :ref:`Static runtime <config_runtime_bootstrap>` layer.
-  message StaticLayer {
-    // This follows the :ref:`runtime protobuf JSON representation encoding
-    // <config_runtime_proto_json>`.
-    google.protobuf.Struct value = 1;
-  }
-
   // :ref:`Disk runtime <config_runtime_local_disk>` layer.
   message DiskLayer {
     // The implementation assumes that the file system tree is accessed via a
@@ -264,27 +257,28 @@ message RuntimeLayer {
   message AdminLayer {
   }
 
-  // [#not-implemented-hide:]
+  // :ref:`Runtime Discovery Service (RTDS) <config_runtime_rtds>` layer.
-  message TdsLayer {
+  message RtdsLayer {
-    // Resource to subscribe to at *tds_config* for the TDS layer.
+    // Resource to subscribe to at *rtds_config* for the RTDS layer.
     string name = 1;
 
-    // TDS configuration source.
+    // RTDS configuration source.
-    envoy.api.v2.core.ConfigSource tds_config = 2;
+    envoy.api.v2.core.ConfigSource rtds_config = 2;
   }
 
   // Descriptive name for the runtime layer. This is only used for the runtime
   // :http:get:`/runtime` output.
-  string name = 1;
+  string name = 1 [(validate.rules).string.min_bytes = 1];
 
   oneof layer_specifier {
-    // Unlike static xDS resources, this static layer is overridable by later
+    // :ref:`Static runtime <config_runtime_bootstrap>` layer.
-    // layers in the runtime virtual filesystem.
+    // This follows the :ref:`runtime protobuf JSON representation encoding
+    // <config_runtime_proto_json>`. Unlike static xDS resources, this static
+    // layer is overridable by later layers in the runtime virtual filesystem.
     google.protobuf.Struct static_layer = 2;
     DiskLayer disk_layer = 3;
     AdminLayer admin_layer = 4;
-    // [#not-implemented-hide:]
+    RtdsLayer rtds_layer = 5;
-    TdsLayer tds_layer = 5;
   }
 }
 

envoy/service/discovery/v2/BUILD

@@ -58,8 +58,8 @@ api_go_grpc_library(
 )
 
 api_proto_library_internal(
-    name = "tds",
+    name = "rtds",
-    srcs = ["tds.proto"],
+    srcs = ["rtds.proto"],
     has_services = 1,
     deps = [
         "//envoy/api/v2:discovery",
@@ -67,8 +67,8 @@ api_proto_library_internal(
 )
 
 api_go_grpc_library(
-    name = "tds",
+    name = "rtds",
-    proto = ":tds",
+    proto = ":rtds",
     deps = [
         "//envoy/api/v2:discovery_go_proto",
     ],

envoy/service/discovery/v2/rtds.proto

@@ -2,7 +2,7 @@ syntax = "proto3";
 
 package envoy.service.discovery.v2;
 
-option java_outer_classname = "TdsProto";
+option java_outer_classname = "RtdsProto";
 option java_multiple_files = true;
 option java_package = "io.envoyproxy.envoy.service.discovery.v2";
 option java_generic_services = true;
@@ -12,18 +12,26 @@ import "envoy/api/v2/discovery.proto";
 import "google/api/annotations.proto";
 import "google/protobuf/struct.proto";
 
+import "validate/validate.proto";
+
+// [#protodoc-title: runTime Discovery Service (RTDS)]
+// RTDS :ref:`configuration overview <config_runtime_rtds>`
+
 // [#not-implemented-hide:] Not configuration. Workaround c++ protobuf issue with importing
 // services: https://github.com/google/protobuf/issues/4221
-message TdsDummy {
+message RtdsDummy {
 }
 
 // Discovery service for Runtime resources.
-// [#not-implemented-hide:]
 service RuntimeDiscoveryService {
   rpc StreamRuntime(stream envoy.api.v2.DiscoveryRequest)
       returns (stream envoy.api.v2.DiscoveryResponse) {
   }
 
+  rpc DeltaRuntime(stream envoy.api.v2.DeltaDiscoveryRequest)
+      returns (stream envoy.api.v2.DeltaDiscoveryResponse) {
+  }
+
   rpc FetchRuntime(envoy.api.v2.DiscoveryRequest) returns (envoy.api.v2.DiscoveryResponse) {
     option (google.api.http) = {
       post: "/v2/discovery:runtime"
@@ -32,8 +40,10 @@ service RuntimeDiscoveryService {
   }
 }
 
-// TDS resource type. This describes a layer in the runtime virtual filesystem.
+// RTDS resource type. This describes a layer in the runtime virtual filesystem.
-// [#not-implemented-hide:]
 message Runtime {
-  google.protobuf.Struct layer = 1;
+  // Runtime resource name. This makes the Runtime a self-describing xDS
+  // resource.
+  string name = 1 [(validate.rules).string.min_bytes = 1];
+  google.protobuf.Struct layer = 2;
 }

test/build/BUILD

@@ -13,7 +13,7 @@ api_cc_test(
         "//envoy/service/accesslog/v2:als",
         "//envoy/service/discovery/v2:ads",
         "//envoy/service/discovery/v2:hds",
-        "//envoy/service/discovery/v2:tds",
+        "//envoy/service/discovery/v2:rtds",
         "//envoy/service/metrics/v2:metrics_service",
         "//envoy/service/ratelimit/v2:rls",
     ],

xds_protocol.rst

@@ -60,6 +60,7 @@ correspondence between an xDS API and a resource type. That is:
 -  CDS: :ref:`envoy.api.v2.Cluster <envoy_api_msg_Cluster>`
 -  EDS: :ref:`envoy.api.v2.ClusterLoadAssignment <envoy_api_msg_ClusterLoadAssignment>`
 -  SDS: :ref:`envoy.api.v2.Auth.Secret <envoy_api_msg_Auth.Secret>`
+-  RTDS: :ref:`envoy.service.discovery.v2.Runtime <envoy_api_msg_service.discovery.v2.Runtime>`
 
 The concept of `type URLs <https://developers.google.com/protocol-buffers/docs/proto3#any>`_ appears below, and takes the form
 `type.googleapis.com/<resource type>`, e.g.