Content-Length header is not set in Golang http client request using PUT method

Question

I'm using Golang 1.4.2 (built from source) and when I try to make an HTTP PUT request via http.Client.Do() the Content-Length header is missing from the request. All my other headers are sent... Am I doing something wrong? When I make the same request via CURL the content-length header is sent. My requests are being made to etcd server, which is setting all my keys to empty values. While this is somewhat novel, it is hardly useful. :)

http://play.golang.org/p/pIoB--bXUT

package main

import (
    "bytes"
    "fmt"
    "net/http"
    "net/http/httputil"
    "net/url"
    "strconv"
)

func main() {
    put := url.Values{}
    put.Set("value", "WHOAH here is my stuff")
    put.Add("ttl","")
    encode := put.Encode()
    req, _ := http.NewRequest("PUT", "http://localhost:2379/v2/keys/somekey", bytes.NewBufferString(encode))
    req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
    req.Header.Add("Content-Length", strconv.Itoa(len(encode)))
    req.Header.Add("X-Content-Length", strconv.Itoa(len(encode)))
    dump, _ := httputil.DumpRequest(req, true)
    fmt.Println(string(dump))
}

yields

PUT /v2/keys/somekey HTTP/1.1
Host: localhost
Content-Type: application/x-www-form-urlencoded
X-Content-Length: 33

ttl=&value=WHOAH+here+is+my+stuff

Answer 1

I was incorrect about Content-Length not being sent, I just wasn't seeing it when using httputil.DumpRequest.

Solution here was to use httputil.DumpRequestOut which properly shows the Content-Length header (and others). It means there is something else going on with my program that is causing etcd to set empty values. If I figure that out I'll update with that solution as well.