1 // Copyright 2018 The etcd Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 // Copyright 2015 The Go Authors. All rights reserved. 16 // Use of this source code is governed by a BSD-style 17 // license that can be found in the LICENSE file. 18 19 // Package httputil provides HTTP utility functions. 20 package httputil 21 22 import ( 23 "io" 24 "io/ioutil" 25 "net" 26 "net/http" 27 ) 28 29 // GracefulClose drains http.Response.Body until it hits EOF 30 // and closes it. This prevents TCP/TLS connections from closing, 31 // therefore available for reuse. 32 // Borrowed from golang/net/context/ctxhttp/cancelreq.go. 33 func GracefulClose(resp *http.Response) { 34 io.Copy(ioutil.Discard, resp.Body) 35 resp.Body.Close() 36 } 37 38 // GetHostname returns the hostname from request Host field. 39 // It returns empty string, if Host field contains invalid 40 // value (e.g. "localhost:::" with too many colons). 41 func GetHostname(req *http.Request) string { 42 if req == nil { 43 return "" 44 } 45 h, _, err := net.SplitHostPort(req.Host) 46 if err != nil { 47 return req.Host 48 } 49 return h 50 } 51