caddy/caddyhttp/httpserver/replacer.go
M-A 8464020f7c Add {whenISO} to record timestamp in ISO 8601 format in UTC. (#1353)
* Add {whenISO} to record timestamp in ISO 8601 format in UTC.

ISO 8601 is the standard time format and is easy to parse.

This change assumes users desiring ISO 8016 generally prefer UTC for simplicity.
This results in {whenISO} to be significantly shorter than {when}:
{when}    = "02/Jan/2006:15:04:05 +0000"
{whenISO} = "2006-01-02T15:04:12Z"

Add unit test to verify both, as there was no unit test for {when}.

* Rename {whenISO} to {when_iso}
2017-01-14 15:54:27 -07:00

325 lines
7.6 KiB
Go

package httpserver
import (
"bytes"
"io"
"io/ioutil"
"net"
"net/http"
"net/http/httputil"
"net/url"
"os"
"path"
"strconv"
"strings"
"time"
)
// requestReplacer is a strings.Replacer which is used to
// encode literal \r and \n characters and keep everything
// on one line
var requestReplacer = strings.NewReplacer(
"\r", "\\r",
"\n", "\\n",
)
var now = time.Now
// Replacer is a type which can replace placeholder
// substrings in a string with actual values from a
// http.Request and ResponseRecorder. Always use
// NewReplacer to get one of these. Any placeholders
// made with Set() should overwrite existing values if
// the key is already used.
type Replacer interface {
Replace(string) string
Set(key, value string)
}
// replacer implements Replacer. customReplacements
// is used to store custom replacements created with
// Set() until the time of replacement, at which point
// they will be used to overwrite other replacements
// if there is a name conflict.
type replacer struct {
customReplacements map[string]string
emptyValue string
responseRecorder *ResponseRecorder
request *http.Request
requestBody *limitWriter
}
type limitWriter struct {
w bytes.Buffer
remain int
}
func newLimitWriter(max int) *limitWriter {
return &limitWriter{
w: bytes.Buffer{},
remain: max,
}
}
func (lw *limitWriter) Write(p []byte) (int, error) {
// skip if we are full
if lw.remain <= 0 {
return len(p), nil
}
if n := len(p); n > lw.remain {
p = p[:lw.remain]
}
n, err := lw.w.Write(p)
lw.remain -= n
return n, err
}
func (lw *limitWriter) String() string {
return lw.w.String()
}
// NewReplacer makes a new replacer based on r and rr which
// are used for request and response placeholders, respectively.
// Request placeholders are created immediately, whereas
// response placeholders are not created until Replace()
// is invoked. rr may be nil if it is not available.
// emptyValue should be the string that is used in place
// of empty string (can still be empty string).
func NewReplacer(r *http.Request, rr *ResponseRecorder, emptyValue string) Replacer {
rb := newLimitWriter(MaxLogBodySize)
if r.Body != nil {
r.Body = struct {
io.Reader
io.Closer
}{io.TeeReader(r.Body, rb), io.Closer(r.Body)}
}
return &replacer{
request: r,
requestBody: rb,
responseRecorder: rr,
customReplacements: make(map[string]string),
emptyValue: emptyValue,
}
}
func canLogRequest(r *http.Request) bool {
if r.Method == "POST" || r.Method == "PUT" {
for _, cType := range r.Header[headerContentType] {
// the cType could have charset and other info
if strings.Contains(cType, contentTypeJSON) || strings.Contains(cType, contentTypeXML) {
return true
}
}
}
return false
}
// Replace performs a replacement of values on s and returns
// the string with the replaced values.
func (r *replacer) Replace(s string) string {
// Do not attempt replacements if no placeholder is found.
if !strings.ContainsAny(s, "{}") {
return s
}
result := ""
for {
idxStart := strings.Index(s, "{")
if idxStart == -1 {
// no placeholder anymore
break
}
idxEnd := strings.Index(s[idxStart:], "}")
if idxEnd == -1 {
// unpaired placeholder
break
}
idxEnd += idxStart
// get a replacement
placeholder := s[idxStart : idxEnd+1]
replacement := r.getSubstitution(placeholder)
// append prefix + replacement
result += s[:idxStart] + replacement
// strip out scanned parts
s = s[idxEnd+1:]
}
// append unscanned parts
return result + s
}
func roundDuration(d time.Duration) time.Duration {
if d >= time.Millisecond {
return round(d, time.Millisecond)
} else if d >= time.Microsecond {
return round(d, time.Microsecond)
}
return d
}
// round rounds d to the nearest r
func round(d, r time.Duration) time.Duration {
if r <= 0 {
return d
}
neg := d < 0
if neg {
d = -d
}
if m := d % r; m+m < r {
d = d - m
} else {
d = d + r - m
}
if neg {
return -d
}
return d
}
// getSubstitution retrieves value from corresponding key
func (r *replacer) getSubstitution(key string) string {
// search custom replacements first
if value, ok := r.customReplacements[key]; ok {
return value
}
// search request headers then
if key[1] == '>' {
want := key[2 : len(key)-1]
for key, values := range r.request.Header {
// Header placeholders (case-insensitive)
if strings.EqualFold(key, want) {
return strings.Join(values, ",")
}
}
}
// search default replacements in the end
switch key {
case "{method}":
return r.request.Method
case "{scheme}":
if r.request.TLS != nil {
return "https"
}
return "http"
case "{hostname}":
name, err := os.Hostname()
if err != nil {
return r.emptyValue
}
return name
case "{host}":
return r.request.Host
case "{hostonly}":
host, _, err := net.SplitHostPort(r.request.Host)
if err != nil {
return r.request.Host
}
return host
case "{path}":
return r.request.URL.Path
case "{path_escaped}":
return url.QueryEscape(r.request.URL.Path)
case "{query}":
return r.request.URL.RawQuery
case "{query_escaped}":
return url.QueryEscape(r.request.URL.RawQuery)
case "{fragment}":
return r.request.URL.Fragment
case "{proto}":
return r.request.Proto
case "{remote}":
host, _, err := net.SplitHostPort(r.request.RemoteAddr)
if err != nil {
return r.request.RemoteAddr
}
return host
case "{port}":
_, port, err := net.SplitHostPort(r.request.RemoteAddr)
if err != nil {
return r.emptyValue
}
return port
case "{uri}":
return r.request.URL.RequestURI()
case "{uri_escaped}":
return url.QueryEscape(r.request.URL.RequestURI())
case "{when}":
return now().Format(timeFormat)
case "{when_iso}":
return now().UTC().Format(timeFormatISOUTC)
case "{file}":
_, file := path.Split(r.request.URL.Path)
return file
case "{dir}":
dir, _ := path.Split(r.request.URL.Path)
return dir
case "{request}":
dump, err := httputil.DumpRequest(r.request, false)
if err != nil {
return r.emptyValue
}
return requestReplacer.Replace(string(dump))
case "{request_body}":
if !canLogRequest(r.request) {
return r.emptyValue
}
_, err := ioutil.ReadAll(r.request.Body)
if err != nil {
if _, ok := err.(MaxBytesExceeded); ok {
return r.emptyValue
}
}
return requestReplacer.Replace(r.requestBody.String())
case "{status}":
if r.responseRecorder == nil {
return r.emptyValue
}
return strconv.Itoa(r.responseRecorder.status)
case "{size}":
if r.responseRecorder == nil {
return r.emptyValue
}
return strconv.Itoa(r.responseRecorder.size)
case "{latency}":
if r.responseRecorder == nil {
return r.emptyValue
}
return roundDuration(time.Since(r.responseRecorder.start)).String()
case "{latency_ms}":
if r.responseRecorder == nil {
return r.emptyValue
}
elapsedDuration := time.Since(r.responseRecorder.start)
return strconv.FormatInt(convertToMilliseconds(elapsedDuration), 10)
}
return r.emptyValue
}
//convertToMilliseconds returns the number of milliseconds in the given duration
func convertToMilliseconds(d time.Duration) int64 {
return d.Nanoseconds() / 1e6
}
// Set sets key to value in the r.customReplacements map.
func (r *replacer) Set(key, value string) {
r.customReplacements["{"+key+"}"] = value
}
const (
timeFormat = "02/Jan/2006:15:04:05 -0700"
timeFormatISOUTC = "2006-01-02T15:04:05Z" // ISO 8601 with timezone to be assumed as UTC
headerContentType = "Content-Type"
contentTypeJSON = "application/json"
contentTypeXML = "application/xml"
// MaxLogBodySize limits the size of logged request's body
MaxLogBodySize = 100 * 1024
)