version/main.go

package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
)

const warning = "//WARNING! DO NOT EDIT THIS FILE BY HAND. IT IS AUTO GENERATED.\n"

const header = "package main\nconst gitVersion = \""

const code = `
import (
	"fmt"
	"os"
)

func init() {
	for _, arg := range os.Args {
        if arg == "-v" || arg == "--version" {
            fmt.Println(gitVersion)
            os.Exit(0)
        }
    }
}
`

func main() {
	cmd := exec.Command("git", "describe", "--tags", "--abbrev=0")
	out, err := cmd.Output()
	if err != nil {
		fmt.Println(err)
		os.Exit(0)
	}
	version := string(out)
	version = version[:len(version)-1]
	content := warning + header + version + "\"" + code

	ioutil.WriteFile("version.go", []byte(content), 0644)
}