I've implemented the most basic Reverse Proxy to pull a page and then add some content to the body. Unfortunately my attempt to add to the html isn't taking effect. The code below just shows the original page but without the "monkeys" I prepended to the response. What additional calls are needed to get this to work? I eventually want to use this to replace css for custom css.
package main
import (
"log"
"net/http"
"net/http/httputil"
"net/url"
"fmt"
"github.com/PuerkitoBio/goquery"
"bytes"
)
type Director func(*http.Request)
func (f Director) Then(g Director) Director {
return func(req *http.Request) {
f(req)
g(req)
}
}
func hostDirector(host string) Director {
return func(req *http.Request) {
req.Host = host
}
}
func UpdateResponse(r *http.Response) error {
doc, err := goquery.NewDocumentFromReader(r.Body)
if err != nil{
//log.New("Research")
log.Fatal("Bad doc %v", err)
return err
}
html, err := goquery.OuterHtml(doc.First())
if err != nil{
log.Fatal("Bad html %v", err)
return err
}
fmt.Printf("Body %v", html)
r.Write(bytes.NewBufferString("monkeys"+html))
return nil
}
func main() {
url, _ := url.Parse("http://cnn.com/")
proxy := httputil.NewSingleHostReverseProxy(url)
d := proxy.Director
// sequence the default director with our host director
proxy.Director = Director(d).Then(hostDirector(url.Hostname()))
proxy.ModifyResponse = UpdateResponse
http.Handle("/", proxy)
log.Fatal(http.ListenAndServe(":9090", nil))
}