Buildbot build json grpc endpoint

milo/api/proto/buildbot.proto

 // Copyright 2016 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 syntax = "proto3";
 
 package milo;
 
 import "google/protobuf/timestamp.proto";
 
 // The buildbot service definition.
 service Buildbot {
   rpc GetCompressedMasterJSON(MasterRequest) returns (CompressedMasterJSON) {}
+  rpc GetBuildbotBuildJSON(BuildbotBuildRequest) returns (BuildbotBuildJSON) {}
 }
 
 // The request containing the name of the master.
 message MasterRequest {
   string name = 1;
 }
 
 // The response message containing master information.
 message CompressedMasterJSON {
   // Whether the master is internal or not.
   bool internal = 1;
 
   // Timestamp of the freshness of the master data.
   google.protobuf.Timestamp modified = 2;
 
   // Gzipped json data of the master.
   bytes data = 3;
 }
+
+// The request for a specific build.
+message BuildbotBuildRequest {
+  string master = 1;
+  string builder = 2;
+  int64 build_num = 3;
+}
+
+// The response message for a specific build.
+message BuildbotBuildJSON {
+  // Json data of the build.
+  bytes data = 1;
+}