func (p *ReverseProxy) doRequestFor(rw http.ResponseWriter, req *http.Request, upstream types.Upstream) (*http.Response, error) {
outreq, err := p.getOutRequest(rw, req, upstream)
if err != nil {
return nil, err
}
return upstream.RoundTrip(outreq)
}
func (p *ReverseProxy) getOutRequest(rw http.ResponseWriter, req *http.Request, upstream types.Upstream) (*http.Request, error) {
outreq := new(http.Request)
*outreq = *req
url := *req.URL
outreq.URL = &url
outreq.Header = http.Header{}
httputils.CopyHeadersWithout(req.Header, outreq.Header, hopHeaders...)
outreq.Header.Set("User-Agent", p.Settings.UserAgent) // If we don't set it, Go sets it for us to something stupid...
outreq.Proto = "HTTP/1.1"
outreq.ProtoMajor = 1
outreq.ProtoMinor = 1
outreq.Close = false
upAddr, err := upstream.GetAddress(p.Settings.UpstreamHashPrefix + req.URL.RequestURI())
if err != nil {
return nil, fmt.Errorf("[%p] Proxy handler could not get an upstream address: %v", req, err)
}
p.Logger.Debugf("[%p] Using upstream %s (%s) to proxy request", req, upAddr, upAddr.OriginalURL)
outreq.URL.Scheme = upAddr.Scheme
outreq.URL.Host = upAddr.Host
// Set the correct host
if p.Settings.HostHeader != "" {
outreq.Host = p.Settings.HostHeader
} else if p.Settings.HostHeaderKeepOriginal {
if req.Host != "" {
outreq.Host = req.Host
} else {
outreq.Host = req.URL.Host
}
} else {
outreq.Host = upAddr.OriginalURL.Host
}
if closeNotifier, ok := rw.(http.CloseNotifier); ok {
reqDone := make(chan struct{})
defer close(reqDone)
clientGone := closeNotifier.CloseNotify()
outreq.Body = struct {
io.Reader
io.Closer
}{
Reader: &runOnFirstRead{
Reader: outreq.Body,
fn: func() {
go func() {
select {
case <-clientGone:
upstream.CancelRequest(outreq)
case <-reqDone:
}
}()
},
},
Closer: outreq.Body,
}
}
if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
// If we aren't the first proxy retain prior
// X-Forwarded-For information as a comma+space
// separated list and fold multiple headers into one.
if prior, ok := outreq.Header["X-Forwarded-For"]; ok {
clientIP = strings.Join(prior, ", ") + ", " + clientIP
}
outreq.Header.Set("X-Forwarded-For", clientIP)
}
return outreq, nil
}