func (f *Forwarder) ServeHTTP(w http.ResponseWriter, req *http.Request) {
start := time.Now().UTC()
response, err := f.roundTripper.RoundTrip(f.copyRequest(req, req.URL))
if err != nil {
f.log.Errorf("Error forwarding to %v, err: %v", req.URL, err)
f.errHandler.ServeHTTP(w, req, err)
return
}
if req.TLS != nil {
f.log.Infof("Round trip: %v, code: %v, duration: %v tls:version: %x, tls:resume:%t, tls:csuite:%x, tls:server:%v",
req.URL, response.StatusCode, time.Now().UTC().Sub(start),
req.TLS.Version,
req.TLS.DidResume,
req.TLS.CipherSuite,
req.TLS.ServerName)
} else {
f.log.Infof("Round trip: %v, code: %v, duration: %v",
req.URL, response.StatusCode, time.Now().UTC().Sub(start))
}
utils.CopyHeaders(w.Header(), response.Header)
w.WriteHeader(response.StatusCode)
written, _ := io.Copy(w, response.Body)
if written != 0 {
w.Header().Set(ContentLength, strconv.FormatInt(written, 10))
}
response.Body.Close()
}
func (f *Forwarder) copyRequest(req *http.Request, u *url.URL) *http.Request {
outReq := new(http.Request)
*outReq = *req // includes shallow copies of maps, but we handle this below
outReq.URL = utils.CopyURL(req.URL)
outReq.URL.Scheme = u.Scheme
outReq.URL.Host = u.Host
outReq.URL.Opaque = req.RequestURI
// raw query is already included in RequestURI, so ignore it to avoid dupes
outReq.URL.RawQuery = ""
// Do not pass client Host header unless optsetter PassHostHeader is set.
if f.passHost != true {
outReq.Host = u.Host
}
outReq.Proto = "HTTP/1.1"
outReq.ProtoMajor = 1
outReq.ProtoMinor = 1
// Overwrite close flag so we can keep persistent connection for the backend servers
outReq.Close = false
outReq.Header = make(http.Header)
utils.CopyHeaders(outReq.Header, req.Header)
if f.rewriter != nil {
f.rewriter.Rewrite(outReq)
}
return outReq
}
func (rw *rewriteHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
oldURL := rawURL(req)
// only continue if the Regexp param matches the URL
if !rw.regexp.MatchString(oldURL) {
rw.next.ServeHTTP(w, req)
return
}
// apply a rewrite regexp to the URL
newURL := rw.regexp.ReplaceAllString(oldURL, rw.replacement)
// replace any variables that may be in there
rewrittenURL := &bytes.Buffer{}
if err := ApplyString(newURL, rewrittenURL, req); err != nil {
rw.errHandler.ServeHTTP(w, req, err)
return
}
// parse the rewritten URL and replace request URL with it
parsedURL, err := url.Parse(rewrittenURL.String())
if err != nil {
rw.errHandler.ServeHTTP(w, req, err)
return
}
if rw.redirect && newURL != oldURL {
(&redirectHandler{u: parsedURL}).ServeHTTP(w, req)
return
}
req.URL = parsedURL
// make sure the request URI corresponds the rewritten URL
req.RequestURI = req.URL.RequestURI()
if !rw.rewriteBody {
rw.next.ServeHTTP(w, req)
return
}
bw := &bufferWriter{header: make(http.Header), buffer: &bytes.Buffer{}}
newBody := &bytes.Buffer{}
rw.next.ServeHTTP(bw, req)
if err := Apply(bw.buffer, newBody, req); err != nil {
log.Errorf("Failed to rewrite response body: %v", err)
return
}
utils.CopyHeaders(w.Header(), bw.Header())
w.Header().Set("Content-Length", strconv.Itoa(newBody.Len()))
w.WriteHeader(bw.code)
io.Copy(w, newBody)
}
func (s *Streamer) copyRequest(req *http.Request, body io.ReadCloser, bodySize int64) *http.Request {
o := *req
o.URL = utils.CopyURL(req.URL)
o.Header = make(http.Header)
utils.CopyHeaders(o.Header, req.Header)
o.ContentLength = bodySize
// remove TransferEncoding that could have been previously set because we have transformed the request from chunked encoding
o.TransferEncoding = []string{}
// http.Transport will close the request body on any error, we are controlling the close process ourselves, so we override the closer here
o.Body = ioutil.NopCloser(body)
return &o
}
func (s *Streamer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
if err := s.checkLimit(req); err != nil {
s.log.Infof("request body over limit: %v", err)
s.errHandler.ServeHTTP(w, req, err)
return
}
// Read the body while keeping limits in mind. This reader controls the maximum bytes
// to read into memory and disk. This reader returns an error if the total request size exceeds the
// prefefined MaxSizeBytes. This can occur if we got chunked request, in this case ContentLength would be set to -1
// and the reader would be unbounded bufio in the http.Server
body, err := multibuf.New(req.Body, multibuf.MaxBytes(s.maxRequestBodyBytes), multibuf.MemBytes(s.memRequestBodyBytes))
if err != nil || body == nil {
s.errHandler.ServeHTTP(w, req, err)
return
}
// Set request body to buffered reader that can replay the read and execute Seek
// Note that we don't change the original request body as it's handled by the http server
// and we don'w want to mess with standard library
defer body.Close()
// We need to set ContentLength based on known request size. The incoming request may have been
// set without content length or using chunked TransferEncoding
totalSize, err := body.Size()
if err != nil {
s.log.Errorf("failed to get size, err %v", err)
s.errHandler.ServeHTTP(w, req, err)
return
}
outreq := s.copyRequest(req, body, totalSize)
attempt := 1
for {
// We create a special writer that will limit the response size, buffer it to disk if necessary
writer, err := multibuf.NewWriterOnce(multibuf.MaxBytes(s.maxResponseBodyBytes), multibuf.MemBytes(s.memResponseBodyBytes))
if err != nil {
s.errHandler.ServeHTTP(w, req, err)
return
}
// We are mimicking http.ResponseWriter to replace writer with our special writer
b := &bufferWriter{
header: make(http.Header),
buffer: writer,
}
defer b.Close()
s.next.ServeHTTP(b, outreq)
var reader multibuf.MultiReader
if b.expectBody(outreq) {
rdr, err := writer.Reader()
if err != nil {
s.log.Errorf("failed to read response, err %v", err)
s.errHandler.ServeHTTP(w, req, err)
return
}
defer rdr.Close()
reader = rdr
}
if (s.retryPredicate == nil || attempt > DefaultMaxRetryAttempts) ||
!s.retryPredicate(&context{r: req, attempt: attempt, responseCode: b.code, log: s.log}) {
utils.CopyHeaders(w.Header(), b.Header())
w.WriteHeader(b.code)
if reader != nil {
io.Copy(w, reader)
}
return
}
attempt += 1
if _, err := body.Seek(0, 0); err != nil {
s.log.Errorf("Failed to rewind: error: %v", err)
s.errHandler.ServeHTTP(w, req, err)
return
}
outreq = s.copyRequest(req, body, totalSize)
s.log.Infof("retry Request(%v %v) attempt %v", req.Method, req.URL, attempt)
}
}