Login via POST does not yield valid session - node.js

Question

I am currently trying to convert a smallish app from nodejs to golang (hence the two tags) but I'm running into a bit of trouble in doing so.
Essentially it is a very simple http POST login which I can't seem to realise. The background is that my university provides a calendar export function and I would like to provide this calendar as a feed that could be added to Google Cal.
Now the thing is that I have the whole thing working in node, but I would really like to be able realise it in go aswell.
The important bit of node code would be
var query = url.parse(req.url, true).query;
var data = {
u: query.user, // Username
p: query.password, // Password
};
needle.post(LOGIN_URL, data, {}, function (error, response) {
//extract cookies etc.
});
which is working like a charm but if I try to do the same in go
import "github.com/parnurzeal/gorequest"
//...
resp, body, err := gorequest.New().Post(LOGIN_URL).Send("u=user&p=pass").End()
//extract cookies etc.
I end up an invalid (timed out) session. I already tried using just net/http in go, which doesn't seem to change anything.
The result the POST request yields is a 302 redirect to an overview page (Btw: it is ASP based). Could it be that this is what's causing the problem, since gorequest then fetches that overview page without the cookies returned in resp, effectively creating a new session that isn't authorized, or am I overlooking something terribly simple?

Answer 1

So it seems that I found the answer myself by following your advice and using "net/http" and digging a little deeper into what the http.Client actually does. To anyone who might encounter similar problems, here is my solution:
http.Client automatically redirects if it receives a 30x response by the server see documentation. Although one can override the redirect policy, I was unable to prevent redirection entirely.
Additionally it seems as if the client has a bug (what I would call it at least), as it drops all header upon redirect see the issue or in the source where new headers are created.
While searching around in net/http I found http.DefaultTransport which is used by http.Client and does not redirect. It seems somewhat lower level and exactly what I was after. The following piece of code demonstrates how I replaced the line realised with gorequest from above:
data := url.Values{"u": {USER}, "p": {PASS}}
req, err := http.NewRequest("POST", LOGIN_URL, bytes.NewBufferString(data.Encode()))
//I needed quite some time to figure out that I needed to set the content type accordingly
req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
//...
resp, err := http.DefaultTransport.RoundTrip(req)
//...
//resp.Header["Set-Cookie"] now contains the login/session cookies
Although I need to extract cookies myself and set a few header values, the solution works perfectly and I am quite happy with it. If anybody has some improvements to my solution or any other advice I am glad to hear it. And thanks to JimB and Volker :).