Steal vtadmin.proto from #7187

Signed-off-by: Sara Bee <855595+doeg@users.noreply.github.com>

proto/vtadmin.proto

@@ -0,0 +1,100 @@
+/*
+Copyright 2020 The Vitess Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// This package contains the types used by VTAdmin (and later an RPC service).
+
+syntax = "proto3";
+option go_package = "vitess.io/vitess/go/vt/proto/vtadmin";
+
+package vtadmin;
+
+import "topodata.proto";
+
+/* Services */
+
+// VTAdmin is the Vitess Admin API service. It provides RPCs that operate on
+// across a range of Vitess clusters.
+service VTAdmin {
+    // GetGates returns all gates across all the specified clusters.
+    rpc GetGates(GetGatesRequest) returns (GetGatesResponse) {};
+    // GetTablet looks up a tablet by hostname across all clusters and returns
+    // the result.
+    rpc GetTablet(GetTabletRequest) returns (Tablet) {};
+    // GetTablets returns all tablets across all the specified clusters.
+    rpc GetTablets(GetTabletsRequest) returns (GetTabletsResponse) {};
+}
+
+/* Data types */
+
+// Cluster represents information about a Vitess cluster.
+message Cluster {
+    string id = 1;
+    string name = 2;
+}
+
+// Tablet groups the topo information of a tablet together with the Vitess
+// cluster it belongs to.
+message Tablet {
+    Cluster cluster = 1;
+    topodata.Tablet tablet = 2;
+
+    enum ServingState {
+        UNKNOWN = 0;
+        SERVING = 1;
+        NOT_SERVING = 2;
+    }
+
+    ServingState state = 3;
+}
+
+// VTGate represents information about a single VTGate host.
+message VTGate {
+    // Hostname is the shortname of the VTGate.
+    string hostname = 1;
+    // Pool is group the VTGate serves queries for. Some deployments segment
+    // VTGates into groups or pools, based on the workloads they serve queries
+    // for. Use of this field is optional.
+    string pool = 2;
+    // Cell is the topology cell the VTGate is in.
+    string cell = 3;
+    // Cluster is the name of the cluster the VTGate serves.
+    string cluster = 4;
+    // Keyspaces is the list of keyspaces-to-watch for the VTGate.
+    repeated string keyspaces = 5;
+}
+
+/* Request/Response types */
+
+message GetGatesRequest {
+    repeated string cluster_ids = 1;
+}
+
+message GetGatesResponse {
+    repeated VTGate gates = 1;
+}
+
+message GetTabletRequest {
+    string hostname = 1;
+    // ClusterIDs is an optional parameter to narrow the scope of the search, if
+    // the caller knows which cluster the tablet may be in, or, to disamiguate if
+    // multiple clusters have a tablet with the same hostname.
+    repeated string cluster_ids = 2;
+}
+
+message GetTabletsRequest {
+    repeated string cluster_ids = 1;
+}
+
+message GetTabletsResponse {
+    repeated Tablet tablets = 1;
+}