Sending POST request in Golang with header
<p>I create my form like this:</p>

<pre><code>form := url.Values{}
form.Add("region", "San Francisco")
if len(params) &gt; 0 { 
    for i := 0; i &lt; len(params); i += 2 { 
        form.Add(params[i], params[i+1])
    }
    testLog.Infof("form %v", form)
</code></pre>

<p>Now if I use</p>

<pre><code>resp, err = http.PostForm(address+r.Path, form)
</code></pre>

<p>then everything works fine, I get back a response with an expected cookie.  </p>

<p>However, I would like to to add a header in which case I can't use <code>PostForm</code> hence I created my <code>POST request</code> manually like:</p>

<pre><code>req, err := http.NewRequest("POST", address+r.Path, strings.NewReader(form.Encode()))
</code></pre>

<p>Then I add stuff to the header and send the request</p>

<pre><code>req.Header.Add("region", "San Francisco") 
resp, err = http.DefaultClient.Do(req)
</code></pre>

<p>But the form is not received and my response does not contain any cookie.</p>

<p>When I print the <code>req</code>, it looks like the form is <code>nil</code>:</p>

<pre><code>&amp;{POST http://localhost:8081/login HTTP/1.1 1 1 map[Region:[San Francisco]] {0xc420553600} 78 [] false localhost:8081 map[] map[] &lt;nil&gt; map[]   &lt;nil&gt; &lt;nil&gt; &lt;nil&gt; &lt;nil&gt;}
</code></pre>