/*
* Minio Cloud Storage, (C) 2017 Minio, Inc.
*
* 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 handlers
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"net/http"
"reflect"
"runtime"
"strings"
"time"
)
// recordRequest - records the first recLen bytes
// of a given io.Reader
type recordRequest struct {
// Data source to record
io.Reader
// Response body should be logged
logBody bool
// Internal recording buffer
buf bytes.Buffer
}
func (r *recordRequest) Read(p []byte) (n int, err error) {
n, err = r.Reader.Read(p)
if r.logBody {
r.buf.Write(p[:n])
}
if err != nil {
return n, err
}
return n, err
}
// Return the bytes that were recorded.
func (r *recordRequest) Data() []byte {
return r.buf.Bytes()
}
// recordResponseWriter - records the first recLen bytes
// of a given http.ResponseWriter
type recordResponseWriter struct {
// Data source to record
http.ResponseWriter
// Response body should be logged
logBody bool
// Internal recording buffer
headers bytes.Buffer
body bytes.Buffer
// The status code of the current HTTP request
statusCode int
// Indicate if headers are written in the log
headersLogged bool
}
// Write the headers into the given buffer
func writeHeaders(w io.Writer, statusCode int, headers http.Header) {
fmt.Fprintf(w, "%d %s\n", statusCode, http.StatusText(statusCode))
for k, v := range headers {
fmt.Fprintf(w, "%s: %s\n", k, v[0])
}
}
// Record the headers.
func (r *recordResponseWriter) WriteHeader(i int) {
r.statusCode = i
if !r.headersLogged {
writeHeaders(&r.headers, i, r.ResponseWriter.Header())
r.headersLogged = true
}
r.ResponseWriter.WriteHeader(i)
}
func (r *recordResponseWriter) Write(p []byte) (n int, err error) {
n, err = r.ResponseWriter.Write(p)
if !r.headersLogged {
// We assume the response code to be '200 OK' when WriteHeader() is not called,
// that way following Golang HTTP response behavior.
writeHeaders(&r.headers, http.StatusOK, r.ResponseWriter.Header())
r.headersLogged = true
}
if (r.statusCode != http.StatusOK && r.statusCode != http.StatusPartialContent && r.statusCode != 0) || r.logBody {
// Always logging error responses.
r.body.Write(p)
}
return n, err
}
// Calls the underlying Flush.
func (r *recordResponseWriter) Flush() {
r.ResponseWriter.(http.Flusher).Flush()
}
// Return response headers.
func (r *recordResponseWriter) Headers() []byte {
return r.headers.Bytes()
}
// Return response body.
func (r *recordResponseWriter) Body() []byte {
return r.body.Bytes()
}
// TraceReqHandlerFunc logs request/response headers and body.
func TraceReqHandlerFunc(f http.HandlerFunc, output io.Writer, logBody bool) http.HandlerFunc {
name := runtime.FuncForPC(reflect.ValueOf(f).Pointer()).Name()
name = strings.TrimPrefix(name, "github.com/minio/minio/cmd.")
bodyPlaceHolder := []byte("<BODY>")
return func(w http.ResponseWriter, r *http.Request) {
const timeFormat = "2006-01-02 15:04:05 -0700"
var reqBodyRecorder *recordRequest
// Generate short random request ID
reqID := fmt.Sprintf("%f", float64(time.Now().UnixNano())/1e10)
reqBodyRecorder = &recordRequest{Reader: r.Body, logBody: logBody}
r.Body = ioutil.NopCloser(reqBodyRecorder)
// Setup a http response body recorder
respBodyRecorder := &recordResponseWriter{ResponseWriter: w, logBody: logBody}
b := bytes.NewBuffer(nil)
fmt.Fprintf(b, "[REQUEST %s] [%s] [%s]\n", name, reqID, time.Now().Format(timeFormat))
f(respBodyRecorder, r)
// Build request log and write it to log file
fmt.Fprintf(b, "%s %s", r.Method, r.URL.Path)
if r.URL.RawQuery != "" {
fmt.Fprintf(b, "?%s", r.URL.RawQuery)
}
fmt.Fprintf(b, "\n")
fmt.Fprintf(b, "Host: %s\n", r.Host)
for k, v := range r.Header {
fmt.Fprintf(b, "%s: %s\n", k, v[0])
}
fmt.Fprintf(b, "\n")
if logBody {
bodyContents := reqBodyRecorder.Data()
if bodyContents != nil {
// If body logging is disabled then we print <BODY> as a placeholder
// for the actual body.
b.Write(bodyContents)
fmt.Fprintf(b, "\n")
}
} else {
b.Write(bodyPlaceHolder)
fmt.Fprintf(b, "\n")
}
fmt.Fprintf(b, "\n")
// Build response log and write it to log file
fmt.Fprintf(b, "[RESPONSE] [%s] [%s]\n", reqID, time.Now().Format(timeFormat))
b.Write(respBodyRecorder.Headers())
fmt.Fprintf(b, "\n")
// recordResponseWriter{} is configured to record only
// responses with http code != 200 & != 206, we don't
// have to check for logBody value here.
bodyContents := respBodyRecorder.Body()
if bodyContents != nil {
b.Write(bodyContents)
fmt.Fprintf(b, "\n")
} else {
if !logBody {
// If there was no error response and body logging is disabled
// then we print <BODY> as a placeholder for the actual body.
b.Write(bodyPlaceHolder)
fmt.Fprintf(b, "\n")
}
}
fmt.Fprintf(b, "\n")
// Write the contents in one shot so that logs don't get interspersed.
output.Write(b.Bytes())
}
}