oauth2_proxy/logging_handler.go

169 lines
4.4 KiB
Go

// largely adapted from https://github.com/gorilla/handlers/blob/master/handlers.go
// to add logging of request duration as last value (and drop referrer)
package main
import (
"fmt"
"io"
"net"
"net/http"
"net/url"
"text/template"
"time"
)
const (
defaultRequestLoggingFormat = "{{.Client}} - {{.Username}} [{{.Timestamp}}] {{.Host}} {{.RequestMethod}} {{.Upstream}} {{.RequestURI}} {{.Protocol}} {{.UserAgent}} {{.StatusCode}} {{.ResponseSize}} {{.RequestDuration}}"
)
// responseLogger is wrapper of http.ResponseWriter that keeps track of its HTTP status
// code and body size
type responseLogger struct {
w http.ResponseWriter
status int
size int
upstream string
authInfo string
}
// Header returns the ResponseWriter's Header
func (l *responseLogger) Header() http.Header {
return l.w.Header()
}
// ExtractGAPMetadata extracts and removes GAP headers from the ResponseWriter's
// Header
func (l *responseLogger) ExtractGAPMetadata() {
upstream := l.w.Header().Get("GAP-Upstream-Address")
if upstream != "" {
l.upstream = upstream
l.w.Header().Del("GAP-Upstream-Address")
}
authInfo := l.w.Header().Get("GAP-Auth")
if authInfo != "" {
l.authInfo = authInfo
l.w.Header().Del("GAP-Auth")
}
}
// Write writes the response using the ResponseWriter
func (l *responseLogger) Write(b []byte) (int, error) {
if l.status == 0 {
// The status will be StatusOK if WriteHeader has not been called yet
l.status = http.StatusOK
}
l.ExtractGAPMetadata()
size, err := l.w.Write(b)
l.size += size
return size, err
}
// WriteHeader writes the status code for the Response
func (l *responseLogger) WriteHeader(s int) {
l.ExtractGAPMetadata()
l.w.WriteHeader(s)
l.status = s
}
// Status returns the response status code
func (l *responseLogger) Status() int {
return l.status
}
// Size returns teh response size
func (l *responseLogger) Size() int {
return l.size
}
// logMessageData is the container for all values that are available as variables in the request logging format.
// All values are pre-formatted strings so it is easy to use them in the format string.
type logMessageData struct {
Client,
Host,
Protocol,
RequestDuration,
RequestMethod,
RequestURI,
ResponseSize,
StatusCode,
Timestamp,
Upstream,
UserAgent,
Username string
}
// loggingHandler is the http.Handler implementation for LoggingHandlerTo and its friends
type loggingHandler struct {
writer io.Writer
handler http.Handler
enabled bool
logTemplate *template.Template
}
// LoggingHandler provides an http.Handler which logs requests to the HTTP server
func LoggingHandler(out io.Writer, h http.Handler, v bool, requestLoggingTpl string) http.Handler {
return loggingHandler{
writer: out,
handler: h,
enabled: v,
logTemplate: template.Must(template.New("request-log").Parse(requestLoggingTpl)),
}
}
func (h loggingHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
t := time.Now()
url := *req.URL
logger := &responseLogger{w: w}
h.handler.ServeHTTP(logger, req)
if !h.enabled {
return
}
h.writeLogLine(logger.authInfo, logger.upstream, req, url, t, logger.Status(), logger.Size())
}
// Log entry for req similar to Apache Common Log Format.
// ts is the timestamp with which the entry should be logged.
// status, size are used to provide the response HTTP status and size.
func (h loggingHandler) writeLogLine(username, upstream string, req *http.Request, url url.URL, ts time.Time, status int, size int) {
if username == "" {
username = "-"
}
if upstream == "" {
upstream = "-"
}
if url.User != nil && username == "-" {
if name := url.User.Username(); name != "" {
username = name
}
}
client := req.Header.Get("X-Real-IP")
if client == "" {
client = req.RemoteAddr
}
if c, _, err := net.SplitHostPort(client); err == nil {
client = c
}
duration := float64(time.Now().Sub(ts)) / float64(time.Second)
h.logTemplate.Execute(h.writer, logMessageData{
Client: client,
Host: req.Host,
Protocol: req.Proto,
RequestDuration: fmt.Sprintf("%0.3f", duration),
RequestMethod: req.Method,
RequestURI: fmt.Sprintf("%q", url.RequestURI()),
ResponseSize: fmt.Sprintf("%d", size),
StatusCode: fmt.Sprintf("%d", status),
Timestamp: ts.Format("02/Jan/2006:15:04:05 -0700"),
Upstream: upstream,
UserAgent: fmt.Sprintf("%q", req.UserAgent()),
Username: username,
})
h.writer.Write([]byte("\n"))
}