traefik/middlewares/accesslog/logger.go
2018-03-23 09:28:03 +01:00

292 lines
7.4 KiB
Go

package accesslog
import (
"context"
"fmt"
"net"
"net/http"
"net/url"
"os"
"path/filepath"
"sync"
"sync/atomic"
"time"
"github.com/containous/traefik/log"
"github.com/containous/traefik/types"
"github.com/sirupsen/logrus"
)
type key string
const (
// DataTableKey is the key within the request context used to
// store the Log Data Table
DataTableKey key = "LogDataTable"
// CommonFormat is the common logging format (CLF)
CommonFormat = "common"
// JSONFormat is the JSON logging format
JSONFormat = "json"
)
// LogHandler will write each request and its response to the access log.
type LogHandler struct {
config *types.AccessLog
logger *logrus.Logger
file *os.File
mu sync.Mutex
httpCodeRanges types.HTTPCodeRanges
}
// NewLogHandler creates a new LogHandler
func NewLogHandler(config *types.AccessLog) (*LogHandler, error) {
file := os.Stdout
if len(config.FilePath) > 0 {
f, err := openAccessLogFile(config.FilePath)
if err != nil {
return nil, fmt.Errorf("error opening access log file: %s", err)
}
file = f
}
var formatter logrus.Formatter
switch config.Format {
case CommonFormat:
formatter = new(CommonLogFormatter)
case JSONFormat:
formatter = new(logrus.JSONFormatter)
default:
return nil, fmt.Errorf("unsupported access log format: %s", config.Format)
}
logger := &logrus.Logger{
Out: file,
Formatter: formatter,
Hooks: make(logrus.LevelHooks),
Level: logrus.InfoLevel,
}
logHandler := &LogHandler{
config: config,
logger: logger,
file: file,
}
if config.Filters != nil {
if httpCodeRanges, err := types.NewHTTPCodeRanges(config.Filters.StatusCodes); err != nil {
log.Errorf("Failed to create new HTTP code ranges: %s", err)
} else {
logHandler.httpCodeRanges = httpCodeRanges
}
}
return logHandler, nil
}
func openAccessLogFile(filePath string) (*os.File, error) {
dir := filepath.Dir(filePath)
if err := os.MkdirAll(dir, 0755); err != nil {
return nil, fmt.Errorf("failed to create log path %s: %s", dir, err)
}
file, err := os.OpenFile(filePath, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0664)
if err != nil {
return nil, fmt.Errorf("error opening file %s: %s", filePath, err)
}
return file, nil
}
// GetLogDataTable gets the request context object that contains logging data. This accretes
// data as the request passes through the middleware chain.
func GetLogDataTable(req *http.Request) *LogData {
return req.Context().Value(DataTableKey).(*LogData)
}
func (l *LogHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request, next http.HandlerFunc) {
now := time.Now().UTC()
core := make(CoreLogData)
logDataTable := &LogData{Core: core, Request: req.Header}
core[StartUTC] = now
core[StartLocal] = now.Local()
reqWithDataTable := req.WithContext(context.WithValue(req.Context(), DataTableKey, logDataTable))
var crr *captureRequestReader
if req.Body != nil {
crr = &captureRequestReader{source: req.Body, count: 0}
reqWithDataTable.Body = crr
}
core[RequestCount] = nextRequestCount()
if req.Host != "" {
core[RequestAddr] = req.Host
core[RequestHost], core[RequestPort] = silentSplitHostPort(req.Host)
}
// copy the URL without the scheme, hostname etc
urlCopy := &url.URL{
Path: req.URL.Path,
RawPath: req.URL.RawPath,
RawQuery: req.URL.RawQuery,
ForceQuery: req.URL.ForceQuery,
Fragment: req.URL.Fragment,
}
urlCopyString := urlCopy.String()
core[RequestMethod] = req.Method
core[RequestPath] = urlCopyString
core[RequestProtocol] = req.Proto
core[RequestLine] = fmt.Sprintf("%s %s %s", req.Method, urlCopyString, req.Proto)
core[ClientAddr] = req.RemoteAddr
core[ClientHost], core[ClientPort] = silentSplitHostPort(req.RemoteAddr)
if forwardedFor := req.Header.Get("X-Forwarded-For"); forwardedFor != "" {
core[ClientHost] = forwardedFor
}
crw := &captureResponseWriter{rw: rw}
next.ServeHTTP(crw, reqWithDataTable)
core[ClientUsername] = usernameIfPresent(reqWithDataTable.URL)
logDataTable.DownstreamResponse = crw.Header()
l.logTheRoundTrip(logDataTable, crr, crw)
}
// Close closes the Logger (i.e. the file etc).
func (l *LogHandler) Close() error {
return l.file.Close()
}
// Rotate closes and reopens the log file to allow for rotation
// by an external source.
func (l *LogHandler) Rotate() error {
var err error
if l.file != nil {
defer func(f *os.File) {
f.Close()
}(l.file)
}
l.file, err = os.OpenFile(l.config.FilePath, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0664)
if err != nil {
return err
}
l.mu.Lock()
defer l.mu.Unlock()
l.logger.Out = l.file
return nil
}
func silentSplitHostPort(value string) (host string, port string) {
host, port, err := net.SplitHostPort(value)
if err != nil {
return value, "-"
}
return host, port
}
func usernameIfPresent(theURL *url.URL) string {
username := "-"
if theURL.User != nil {
if name := theURL.User.Username(); name != "" {
username = name
}
}
return username
}
// Logging handler to log frontend name, backend name, and elapsed time
func (l *LogHandler) logTheRoundTrip(logDataTable *LogData, crr *captureRequestReader, crw *captureResponseWriter) {
core := logDataTable.Core
retryAttempts, ok := core[RetryAttempts].(int)
if !ok {
retryAttempts = 0
}
core[RetryAttempts] = retryAttempts
if crr != nil {
core[RequestContentSize] = crr.count
}
core[DownstreamStatus] = crw.Status()
if l.keepAccessLog(crw.Status(), retryAttempts) {
core[DownstreamStatusLine] = fmt.Sprintf("%03d %s", crw.Status(), http.StatusText(crw.Status()))
core[DownstreamContentSize] = crw.Size()
if original, ok := core[OriginContentSize]; ok {
o64 := original.(int64)
if o64 != crw.Size() && 0 != crw.Size() {
core[GzipRatio] = float64(o64) / float64(crw.Size())
}
}
// n.b. take care to perform time arithmetic using UTC to avoid errors at DST boundaries
total := time.Now().UTC().Sub(core[StartUTC].(time.Time))
core[Duration] = total
core[Overhead] = total
if origin, ok := core[OriginDuration]; ok {
core[Overhead] = total - origin.(time.Duration)
}
fields := logrus.Fields{}
for k, v := range logDataTable.Core {
if l.config.Fields.Keep(k) {
fields[k] = v
}
}
l.redactHeaders(logDataTable.Request, fields, "request_")
l.redactHeaders(logDataTable.OriginResponse, fields, "origin_")
l.redactHeaders(logDataTable.DownstreamResponse, fields, "downstream_")
l.mu.Lock()
defer l.mu.Unlock()
l.logger.WithFields(fields).Println()
}
}
func (l *LogHandler) redactHeaders(headers http.Header, fields logrus.Fields, prefix string) {
for k := range headers {
v := l.config.Fields.KeepHeader(k)
if v == types.AccessLogKeep {
fields[prefix+k] = headers.Get(k)
} else if v == types.AccessLogRedact {
fields[prefix+k] = "REDACTED"
}
}
}
func (l *LogHandler) keepAccessLog(statusCode, retryAttempts int) bool {
switch {
case l.config.Filters == nil:
// no filters were specified
return true
case len(l.httpCodeRanges) == 0 && l.config.Filters.RetryAttempts == false:
// empty filters were specified, e.g. by passing --accessLog.filters only (without other filter options)
return true
case l.httpCodeRanges.Contains(statusCode):
return true
case l.config.Filters.RetryAttempts == true && retryAttempts > 0:
return true
default:
return false
}
}
//-------------------------------------------------------------------------------------------------
var requestCounter uint64 // Request ID
func nextRequestCount() uint64 {
return atomic.AddUint64(&requestCounter, 1)
}