forked from codegangsta/gin
/
proxy.go
99 lines (87 loc) · 1.91 KB
/
proxy.go
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package gin
import (
"fmt"
"io"
"net"
"net/http"
"net/http/httputil"
"net/url"
"strings"
)
type Proxy struct {
listener net.Listener
proxy *httputil.ReverseProxy
builder Builder
runner Runner
to *url.URL
}
func NewProxy(builder Builder, runner Runner) *Proxy {
return &Proxy{
builder: builder,
runner: runner,
}
}
func (p *Proxy) Run(config *Config) error {
// create our reverse proxy
url, err := url.Parse(config.ProxyTo)
if err != nil {
return err
}
p.proxy = httputil.NewSingleHostReverseProxy(url)
p.to = url
p.listener, err = net.Listen("tcp", fmt.Sprintf(":%d", config.Port))
if err != nil {
return err
}
go http.Serve(p.listener, http.HandlerFunc(p.defaultHandler))
return nil
}
func (p *Proxy) Close() error {
return p.listener.Close()
}
func (p *Proxy) defaultHandler(res http.ResponseWriter, req *http.Request) {
errors := p.builder.Errors()
if len(errors) > 0 {
res.Write([]byte(errors))
} else {
p.runner.Run()
if strings.ToLower(req.Header.Get("Upgrade")) == "websocket" || strings.ToLower(req.Header.Get("Accept")) == "text/event-stream" {
proxyWebsocket(res, req, p.to)
} else {
p.proxy.ServeHTTP(res, req)
}
}
}
func proxyWebsocket(w http.ResponseWriter, r *http.Request, host *url.URL) {
d, err := net.Dial("tcp", host.Host)
if err != nil {
http.Error(w, "Error contacting backend server.", 500)
fmt.Errorf("Error dialing websocket backend %s: %v", host, err)
return
}
hj, ok := w.(http.Hijacker)
if !ok {
http.Error(w, "Not a hijacker?", 500)
return
}
nc, _, err := hj.Hijack()
if err != nil {
fmt.Errorf("Hijack error: %v", err)
return
}
defer nc.Close()
defer d.Close()
err = r.Write(d)
if err != nil {
fmt.Errorf("Error copying request to target: %v", err)
return
}
errc := make(chan error, 2)
cp := func(dst io.Writer, src io.Reader) {
_, err := io.Copy(dst, src)
errc <- err
}
go cp(d, nc)
go cp(nc, d)
<-errc
}