io - Reading from a Reader multiple times -

i'm building simple caching proxy intercepts http requests, grabs content in response.body, writes client. problem is, read response.body, write client contains empty body (everything else, headers, written expected).

here's current code:

func requesthandler(w http.responsewriter, r *http.request) {     client := &http.client{}     r.requesturi = ""     response, err := client.do(r)     defer response.body.close()     if err != nil {         log.fatal(err)     }     content, _ := ioutil.readall(response.body)     cachepage(response.request.url.string(), content)     response.write(w) } 

if remove content, _ , cachepage lines, works fine. lines included, requests return , empty body. idea how can just body of http.response , still write out response in full http.responsewriter?

you not need read response second time. have data in hand , can write directly response writer.

the call

response.write(w) 

writes response in wire format server's response body. not want proxy. need copy headers, status , body server response individually.

i have noted other issues in code comments below.

i recommend using standard library's reverseproxy or copying , modifying meet needs.

func requesthandler(w http.responsewriter, r *http.request) {      // no need make client, use default     // client := &http.client{}       r.requesturi = ""     response, err := http.defaultclient.do(r)      // response can nil, close after error check     // defer response.body.close()       if err != nil {         log.fatal(err)     }     defer response.body.close()       // check errors! always.     // content, _ := ioutil.readall(response.body)     content, err := ioutil.readall(response.body)     if err != nil {          // handle error     }     cachepage(response.request.url.string(), content)      // write method writes response in wire format w.     // because server handles wire format, need     // copy individual pieces.     // response.write(w)      // copy headers     k, v := range response.header {        w.header()[k] = v     }     // copy status code     w.writeheader(response.statuscode)      // write response body.     w.write(content) }