Square Connect item image upload in Golang

upload.go

package main

import (
	"bytes"
	"fmt"
	"io"
	"log"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
)

// Creates a new file upload http request with optional extra params
func newfileUploadRequest(uri string, token string, paramName, path string) (*http.Request, error) {
	file, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile(paramName, filepath.Base(path))
	if err != nil {
		return nil, err
	}
	_, err = io.Copy(part, file)

	err = writer.Close()
	if err != nil {
		return nil, err
	}

	req, err := http.NewRequest("POST", uri, body)
	if err != nil {
		return nil, err
	}
	req.Header.Add("Authorization", "Bearer "+token)
	req.Header.Add("Content-Type", writer.FormDataContentType())

	return req, nil
}

func main() {
	uri := "https://connect.squareup.com/v1/me/items/THE-ITEM-ID/image"
	path, _ := os.Getwd()
	path += "/THE-FILE-NAME"
	token := "YOUR-ACCESS-TOKEN"
	request, err := newfileUploadRequest(uri, token, "image_data", path)
	if err != nil {
		log.Fatal(err)
	}
	client := &http.Client{}
	resp, err := client.Do(request)
	if err != nil {
		log.Fatal(err)
	} else {
		body := &bytes.Buffer{}
		_, err := body.ReadFrom(resp.Body)
		if err != nil {
			log.Fatal(err)
		}
		resp.Body.Close()
		fmt.Println(resp.StatusCode)
		fmt.Println(resp.Header)
		fmt.Println(body)
	}
}