consul/vendor/github.com/envoyproxy/go-control-plane/pkg/server/gateway.go

96 lines
2.6 KiB
Go

// Copyright 2018 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 server
import (
"bytes"
"io/ioutil"
"net/http"
"path"
"github.com/gogo/protobuf/jsonpb"
"github.com/envoyproxy/go-control-plane/envoy/api/v2"
"github.com/envoyproxy/go-control-plane/pkg/cache"
"github.com/envoyproxy/go-control-plane/pkg/log"
)
// HTTPGateway is a custom implementation of [gRPC gateway](https://github.com/grpc-ecosystem/grpc-gateway)
// specialized to Envoy xDS API.
type HTTPGateway struct {
// Log is an optional log for errors in response write
Log log.Logger
// Server is the underlying gRPC server
Server Server
}
func (h *HTTPGateway) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
p := path.Clean(req.URL.Path)
typeURL := ""
switch p {
case "/v2/discovery:endpoints":
typeURL = cache.EndpointType
case "/v2/discovery:clusters":
typeURL = cache.ClusterType
case "/v2/discovery:listeners":
typeURL = cache.ListenerType
case "/v2/discovery:routes":
typeURL = cache.RouteType
default:
http.Error(resp, "no endpoint", http.StatusNotFound)
return
}
if req.Body == nil {
http.Error(resp, "empty body", http.StatusBadRequest)
return
}
body, err := ioutil.ReadAll(req.Body)
if err != nil {
http.Error(resp, "cannot read body", http.StatusBadRequest)
return
}
// parse as JSON
out := &v2.DiscoveryRequest{}
err = jsonpb.UnmarshalString(string(body), out)
if err != nil {
http.Error(resp, "cannot parse JSON body: "+err.Error(), http.StatusBadRequest)
return
}
out.TypeUrl = typeURL
// fetch results
res, err := h.Server.Fetch(req.Context(), out)
if err != nil {
// Note that this is treated as internal error. We may want to use another code for
// the latest version fetch request.
http.Error(resp, "fetch error: "+err.Error(), http.StatusInternalServerError)
return
}
buf := &bytes.Buffer{}
if err := (&jsonpb.Marshaler{OrigName: true}).Marshal(buf, res); err != nil {
http.Error(resp, "marshal error: "+err.Error(), http.StatusInternalServerError)
}
if _, err = resp.Write(buf.Bytes()); err != nil && h.Log != nil {
h.Log.Errorf("gateway error: %v", err)
}
}