Golang: how to read response body of ReverseProxy?

Question

package main

import (
    \"net/http\"
    \"net/http/httputil\"
    \"net/url\"
)

func main() {
    target := &url.URL{Scheme: \"http\", Host: \"www.google.com\"}         


        

Answer 1

From source code httptest.ResponseRecorder is use for get the response from the handler

func TestModifyResponseClosesBody(t *testing.T) {
    req, _ := http.NewRequest("GET", "http://foo.tld/", nil)
    req.RemoteAddr = "1.2.3.4:56789"
    closeCheck := new(checkCloser)
    logBuf := new(bytes.Buffer)
    outErr := errors.New("ModifyResponse error")
    rp := &ReverseProxy{
        Director: func(req *http.Request) {},
        Transport: &staticTransport{&http.Response{
            StatusCode: 200,
            Body:       closeCheck,
        }},
        ErrorLog: log.New(logBuf, "", 0),
        ModifyResponse: func(*http.Response) error {
            return outErr
        },
    }
    rec := httptest.NewRecorder()
    rp.ServeHTTP(rec, req)
    res := rec.Result()
    if g, e := res.StatusCode, http.StatusBadGateway; g != e {
        t.Errorf("got res.StatusCode %d; expected %d", g, e)
    }
    if !closeCheck.closed {
        t.Errorf("body should have been closed")
    }
    if g, e := logBuf.String(), outErr.Error(); !strings.Contains(g, e) {
        t.Errorf("ErrorLog %q does not contain %q", g, e)
    }
}