[go-nuts] httputils.ReverseProxy and api.github.com

I'd compare raw requests produced by curl and your program e.g. using
ngrep(8).

You need to set the Host field on the http.Request too. (Also, a
ReverseProxy is a handler, so you can get rid of the HandleFunc)

director := func(req *http.Request) {
req.URL.Scheme = "https"
req.URL.Host = "api.github.com"
req.Host = "api.github.com"

log.Println(req.Method, req.URL.String())
log.Println(req.UserAgent())
}
proxy := &httputil.ReverseProxy{
Director: director,
}

log.Fatal(http.ListenAndServe(":8181", proxy))

Hey James,

This did not do the trick (note i'm setting the req.Host):

http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
director := func(req *http.Request) {
req = r
req.URL.Scheme = "https"
req.URL.Host = "api.github.com"
req.Host = "api.github.com"
}

proxy := &httputil.ReverseProxy{Director: director}
proxy.ServeHTTP(w, r)
})

log.Fatal(http.ListenAndServe(":8181", nil))

This didn't do the trick either (not including the req.Host):
director := func(req *http.Request) {
req.URL.Scheme = "https"
req.URL.Host = "api.github.com"
}

proxy := &httputil.ReverseProxy{Director: director}

log.Fatal(http.ListenAndServe(":8181", proxy))

But you're suggestion works:

director := func(req *http.Request) {
req.URL.Scheme = "https"
req.URL.Host = "api.github.com"
req.Host = "api.github.com"
}

proxy := &httputil.ReverseProxy{Director: director}

log.Fatal(http.ListenAndServe(":8181", proxy))

It seems like the extra HandleFunc also influenced the unexpected
behaviour, do you have any hints why this would be?

Don't assign r to req, it's already a copy of r. They're both pointers, so
you're reassigning the address of "r", which is is the original request,
to the proxy's request, so you're no longer modifying the request that's
being sent.

It would also work if you did

     *req = *r

but that's already done for you in the ReverseProxy.


You are also creating a new proxy for each request, which is unneeded.

Thanks James, makes sense - I just copied this snipped for reproducing the
problem - apparently it was a crappy to begin with