traefik/pkg/server/service/proxy.go
2020-04-27 18:12:04 +02:00

118 lines
3.8 KiB
Go

package service
import (
"context"
"fmt"
"io"
"net"
"net/http"
"net/http/httputil"
"net/url"
"time"
"github.com/containous/traefik/v2/pkg/config/dynamic"
"github.com/containous/traefik/v2/pkg/log"
"github.com/containous/traefik/v2/pkg/types"
)
// StatusClientClosedRequest non-standard HTTP status code for client disconnection
const StatusClientClosedRequest = 499
// StatusClientClosedRequestText non-standard HTTP status for client disconnection
const StatusClientClosedRequestText = "Client Closed Request"
func buildProxy(passHostHeader *bool, responseForwarding *dynamic.ResponseForwarding, defaultRoundTripper http.RoundTripper, bufferPool httputil.BufferPool, responseModifier func(*http.Response) error) (http.Handler, error) {
var flushInterval types.Duration
if responseForwarding != nil {
err := flushInterval.Set(responseForwarding.FlushInterval)
if err != nil {
return nil, fmt.Errorf("error creating flush interval: %v", err)
}
}
if flushInterval == 0 {
flushInterval = types.Duration(100 * time.Millisecond)
}
proxy := &httputil.ReverseProxy{
Director: func(outReq *http.Request) {
u := outReq.URL
if outReq.RequestURI != "" {
parsedURL, err := url.ParseRequestURI(outReq.RequestURI)
if err == nil {
u = parsedURL
}
}
outReq.URL.Path = u.Path
outReq.URL.RawPath = u.RawPath
outReq.URL.RawQuery = u.RawQuery
outReq.RequestURI = "" // Outgoing request should not have RequestURI
outReq.Proto = "HTTP/1.1"
outReq.ProtoMajor = 1
outReq.ProtoMinor = 1
if _, ok := outReq.Header["User-Agent"]; !ok {
outReq.Header.Set("User-Agent", "")
}
// Do not pass client Host header unless optsetter PassHostHeader is set.
if passHostHeader != nil && !*passHostHeader {
outReq.Host = outReq.URL.Host
}
// Even if the websocket RFC says that headers should be case-insensitive,
// some servers need Sec-WebSocket-Key, Sec-WebSocket-Extensions, Sec-WebSocket-Accept,
// Sec-WebSocket-Protocol and Sec-WebSocket-Version to be case-sensitive.
// https://tools.ietf.org/html/rfc6455#page-20
outReq.Header["Sec-WebSocket-Key"] = outReq.Header["Sec-Websocket-Key"]
outReq.Header["Sec-WebSocket-Extensions"] = outReq.Header["Sec-Websocket-Extensions"]
outReq.Header["Sec-WebSocket-Accept"] = outReq.Header["Sec-Websocket-Accept"]
outReq.Header["Sec-WebSocket-Protocol"] = outReq.Header["Sec-Websocket-Protocol"]
outReq.Header["Sec-WebSocket-Version"] = outReq.Header["Sec-Websocket-Version"]
delete(outReq.Header, "Sec-Websocket-Key")
delete(outReq.Header, "Sec-Websocket-Extensions")
delete(outReq.Header, "Sec-Websocket-Accept")
delete(outReq.Header, "Sec-Websocket-Protocol")
delete(outReq.Header, "Sec-Websocket-Version")
},
Transport: defaultRoundTripper,
FlushInterval: time.Duration(flushInterval),
ModifyResponse: responseModifier,
BufferPool: bufferPool,
ErrorHandler: func(w http.ResponseWriter, request *http.Request, err error) {
statusCode := http.StatusInternalServerError
switch {
case err == io.EOF:
statusCode = http.StatusBadGateway
case err == context.Canceled:
statusCode = StatusClientClosedRequest
default:
if e, ok := err.(net.Error); ok {
if e.Timeout() {
statusCode = http.StatusGatewayTimeout
} else {
statusCode = http.StatusBadGateway
}
}
}
log.Debugf("'%d %s' caused by: %v", statusCode, statusText(statusCode), err)
w.WriteHeader(statusCode)
_, werr := w.Write([]byte(statusText(statusCode)))
if werr != nil {
log.Debugf("Error while writing status code", werr)
}
},
}
return proxy, nil
}
func statusText(statusCode int) string {
if statusCode == StatusClientClosedRequest {
return StatusClientClosedRequestText
}
return http.StatusText(statusCode)
}