1// Copyright 2017 Google Inc. All Rights Reserved. 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 15package main 16 17import ( 18 "bytes" 19 "fmt" 20 "io" 21 "io/ioutil" 22 "net/http" 23 "os" 24) 25 26type logTransport struct { 27 rt http.RoundTripper 28} 29 30func (t *logTransport) RoundTrip(req *http.Request) (*http.Response, error) { 31 var buf bytes.Buffer 32 33 os.Stdout.Write([]byte("\n[request]\n")) 34 if req.Body != nil { 35 req.Body = ioutil.NopCloser(&readButCopy{req.Body, &buf}) 36 } 37 req.Write(os.Stdout) 38 if req.Body != nil { 39 req.Body = ioutil.NopCloser(&buf) 40 } 41 os.Stdout.Write([]byte("\n[/request]\n")) 42 43 res, err := t.rt.RoundTrip(req) 44 45 fmt.Printf("[response]\n") 46 if err != nil { 47 fmt.Printf("ERROR: %v", err) 48 } else { 49 body := res.Body 50 res.Body = nil 51 res.Write(os.Stdout) 52 if body != nil { 53 res.Body = ioutil.NopCloser(&echoAsRead{body}) 54 } 55 } 56 57 return res, err 58} 59 60type echoAsRead struct { 61 src io.Reader 62} 63 64func (r *echoAsRead) Read(p []byte) (int, error) { 65 n, err := r.src.Read(p) 66 if n > 0 { 67 os.Stdout.Write(p[:n]) 68 } 69 if err == io.EOF { 70 fmt.Printf("\n[/response]\n") 71 } 72 return n, err 73} 74 75type readButCopy struct { 76 src io.Reader 77 dst io.Writer 78} 79 80func (r *readButCopy) Read(p []byte) (int, error) { 81 n, err := r.src.Read(p) 82 if n > 0 { 83 r.dst.Write(p[:n]) 84 } 85 return n, err 86} 87