https://github.com/qvl/gh-backup/issues/15

release.go

package main

import (
	"archive/zip"
	"fmt"
	"io"
	"os"
	"os/exec"
	"path/filepath"
)

const (
	binary    = "gh-backup"
	usage     = "Usage: go run release <version>"
	directory = "releases"
)

var releases = []struct{ tag, os, arch string }{
	{"Windows-64bit", "windows", "amd64"},
	{"MacOS-64bit", "darwin", "amd64"},
	{"Linux-64bit", "linux", "amd64"},
}

func main() {
	if len(os.Args) != 2 {
		fmt.Println(usage)
		os.Exit(1)
	}
	version := os.Args[1]

	// ensure directory
	fatal(os.MkdirAll(directory, os.ModePerm))

	for _, b := range releases {
		release(b.tag, b.os, b.arch, version)
	}
}

func release(tag, system, arch, version string) {
	target := binary + "-" + version + "-" + tag
	zipFile := filepath.Join(directory, target+".zip")

	print("Building %s", tag)
	build(system, arch)

	print("Creating zip file %s", zipFile)
	createZip(zipFile, target, "README.md", binary)

	fatal(os.Remove(binary))
}

func build(system, arch string) {
	cmd := exec.Command("go", "build", "-o="+binary)
	cmd.Env = []string{"GOOS=" + system, "GOARCH=" + arch}
	cmd.Stderr = os.Stderr
	err := cmd.Run()
	fatal(err)
}

func createZip(filename, target string, files ...string) {
	zipFile, err := os.Create(filename)
	fatal(err)
	defer func() {
		fatal(zipFile.Close())
	}()
	z := zip.NewWriter(zipFile)
	defer func() {
		fatal(z.Close())
	}()

	for _, f := range files {
		r, err := os.Open(f)
		fatal(err)
		w, err := z.Create(filepath.Join(target, f))
		fatal(err)
		_, err = io.Copy(w, r)
		fatal(err)
	}

}

func print(s string, args ...interface{}) {
	fmt.Fprintf(os.Stderr, s+"\n", args...)
}

func fatal(err error) {
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}