Add Trace Service Support.

api/BUILD

@@ -324,6 +324,18 @@ api_go_proto_library(
     ],
 )
 
+api_proto_library(
+    name = "trace_service",
+    srcs = ["trace_service.proto"],
+    has_services = 1,
+    require_py = 0,
+    deps = [
+        ":base",
+        ":grpc_service",
+        "@io_opencensus_trace//:trace_model",
+    ],
+)
+
 # TODO(htuch): Grow this to cover everything we want to generate docs for, so we can just invoke
 # bazel build //api --aspects tools/protodoc/protodoc.bzl%proto_doc_aspect  --output_groups=rst
 proto_library(

api/trace_service.proto

@@ -0,0 +1,47 @@
+syntax = "proto3";
+
+// [#proto-status: draft]
+
+package envoy.api.v2;
+
+import "api/base.proto";
+import "api/grpc_service.proto";
+import "trace.proto";
+
+import "google/api/annotations.proto";
+
+import "validate/validate.proto";
+
+// Service for streaming traces to server that consumes the trace data. It
+// uses OpenCensus data model as a standard to represent trace information.
+service TraceService {
+  // Envoy will connect and send StreamTracesMessage messages forever. It does
+  // not expect any response to be sent as nothing would be done in the case
+  // of failure.
+  rpc StreamTraces(stream StreamTracesMessage) returns (StreamTracesResponse) {
+  }
+}
+
+message StreamTracesResponse {
+}
+
+message StreamTracesMessage {
+  message Identifier {
+    // The node sending the access log messages over the stream.
+    Node node = 1 [(validate.rules).message.required = true];
+  }
+
+  // Identifier data effectively is a structured metadata.
+  // As a performance optimization this will only be sent in the first message
+  // on the stream.
+  Identifier identifier = 1;
+
+  // A list of Span entries
+  repeated opencensus.proto.trace.Span spans = 2;
+}
+
+// Configuration structure.
+message TraceServiceConfig {
+  // The upstream gRPC cluster that hosts the metrics service.
+  GrpcService grpc_service = 1 [(validate.rules).message.required = true];
+}

bazel/repositories.bzl

@@ -1,6 +1,7 @@
 GOOGLEAPIS_SHA = "5c6df0cd18c6a429eab739fb711c27f6e1393366" # May 14, 2017
 GOGOPROTO_SHA = "342cbe0a04158f6dcb03ca0079991a51a4248c02" # Oct 7, 2017
 PROMETHEUS_SHA = "6f3806018612930941127f2a7c6c453ba2c527d2" # Nov 02, 2017
+OPENCENSUS_SHA = "993c711ba22a5f08c1d4de58a3c07466995ed962" # Dec 13, 2017
 
 PGV_GIT_SHA = "bd6d057e957fe184dfe76805951803af153be497"
 
@@ -200,3 +201,21 @@ api_proto_library(
 )
         """,
     )
+
+    native.new_http_archive(
+        name = "io_opencensus_trace",
+        strip_prefix = "opencensus-proto-" + OPENCENSUS_SHA + "/opencensus/proto/trace",
+        url = "https://github.com/census-instrumentation/opencensus-proto/archive/" + OPENCENSUS_SHA + ".tar.gz",
+        build_file_content = """
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_library")
+
+api_proto_library(
+    name = "trace_model",
+    srcs = [
+        "trace.proto",
+    ],
+)
+        """,
+    )
+
+