feat: add vendor

vendor/github.com/envoyproxy/go-control-plane/pkg/server/rest/v3/server.go

@@ -0,0 +1,65 @@
+// Copyright 2020 Envoyproxy 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.
+
+// Package rest provides an implementation of REST-JSON part of XDS server
+package rest
+
+import (
+	"context"
+	"errors"
+
+	discovery "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v3"
+	"github.com/envoyproxy/go-control-plane/pkg/cache/v3"
+)
+
+type Server interface {
+	Fetch(context.Context, *discovery.DiscoveryRequest) (*discovery.DiscoveryResponse, error)
+}
+
+type Callbacks interface {
+	// OnFetchRequest is called for each Fetch request. Returning an error will end processing of the
+	// request and respond with an error.
+	OnFetchRequest(context.Context, *discovery.DiscoveryRequest) error
+	// OnFetchResponse is called immediately prior to sending a response.
+	OnFetchResponse(*discovery.DiscoveryRequest, *discovery.DiscoveryResponse)
+}
+
+func NewServer(config cache.ConfigFetcher, callbacks Callbacks) Server {
+	return &server{cache: config, callbacks: callbacks}
+}
+
+type server struct {
+	cache     cache.ConfigFetcher
+	callbacks Callbacks
+}
+
+func (s *server) Fetch(ctx context.Context, req *discovery.DiscoveryRequest) (*discovery.DiscoveryResponse, error) {
+	if s.callbacks != nil {
+		if err := s.callbacks.OnFetchRequest(ctx, req); err != nil {
+			return nil, err
+		}
+	}
+	resp, err := s.cache.Fetch(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	if resp == nil {
+		return nil, errors.New("missing response")
+	}
+	out, err := resp.GetDiscoveryResponse()
+	if s.callbacks != nil {
+		s.callbacks.OnFetchResponse(req, out)
+	}
+	return out, err
+}