An example of how to make a POST request using Go

post_example.go

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"strings"
)

func main() {
	dest := "http://example.com/createItem"
	form := url.Values{}
	form.Add("name", "some_name")
	form.Add("mode", "com.cloudbees.hudson.plugins.folder.Folder")

	req, err := http.NewRequest("POST", dest, strings.NewReader(form.Encode()))

	if err != nil {
		// handle error encoding form values and building the request
	}

	// Add headers. I don't know what was in the #{jenkins_crumb} so I'm assuming it's a token of some kind.
	req.Header.Add("Authorization", "Bearer token=\"token\"")
	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

	// Actually Make the request
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		// handle error from performing the request
	}

	defer res.Body.Close()
	body, _ := ioutil.ReadAll(res.Body)
	fmt.Println(body)
}