golang download parsing netrc

main.go

package main

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

func main() {
	downloadFile("https://github.com/sighupio/furyctl-provisioners/archive/vsphere.zip", "/tmp/vsphere.zip", "/Users/angelbarrerasanchez-sighup/work/sighup/furyctl/demo/bootstrap/configuration/.netrc")
}

func downloadFile(fileURL string, filepath string, netrcfile string) error {
	data, err := ioutil.ReadFile(netrcfile)
	authMap := parseNetrc(string(data))
	u, err := url.Parse(fileURL)
	if err != nil {
		panic(err)
	}
	// Looking for the right user and password
	auth := authMap[u.Host]

	client := &http.Client{}

	req, err := http.NewRequest("GET", fileURL, nil)
	req.SetBasicAuth(auth.login, auth.password)
	resp, err := client.Do(req)

	// // Get the data
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	// Create the file
	out, err := os.Create(filepath)
	if err != nil {
		return err
	}
	defer out.Close()

	// Write the body to file
	_, err = io.Copy(out, resp.Body)
	return err
}

// The following functions were extracted from src/cmd/go/internal/web2/web.go
// as of https://golang.org/cl/161698.

type netrcLine struct {
	machine  string
	login    string
	password string
}

func parseNetrc(data string) map[string]netrcLine {
	// See https://www.gnu.org/software/inetutils/manual/html_node/The-_002enetrc-file.html
	// for documentation on the .netrc format.
	m := make(map[string]netrcLine)
	var l netrcLine
	inMacro := false
	for _, line := range strings.Split(data, "\n") {
		if inMacro {
			if line == "" {
				inMacro = false
			}
			continue
		}

		f := strings.Fields(line)
		i := 0
		for ; i < len(f)-1; i += 2 {
			// Reset at each "machine" token.
			// “The auto-login process searches the .netrc file for a machine token
			// that matches […]. Once a match is made, the subsequent .netrc tokens
			// are processed, stopping when the end of file is reached or another
			// machine or a default token is encountered.”
			switch f[i] {
			case "machine":
				l = netrcLine{machine: f[i+1]}
			case "default":
				break
			case "login":
				l.login = f[i+1]
			case "password":
				l.password = f[i+1]
			case "macdef":
				// “A macro is defined with the specified name; its contents begin with
				// the next .netrc line and continue until a null line (consecutive
				// new-line characters) is encountered.”
				inMacro = true
			}
			if l.machine != "" && l.login != "" && l.password != "" {
				m[l.machine] = l
				l = netrcLine{}
			}
		}

		if i < len(f) && f[i] == "default" {
			// “There can be only one default token, and it must be after all machine tokens.”
			break
		}
	}

	return m
}