UUID without dependencies in Go

Today I saw that the size of my vendor/ folder in Golang project is around 150M. I am using glide there and there are 24 dependencies (it’s a program with multiple data storage connectors, notifications, etc.), so I decided to review it and reduce the amount of 3rd party libraries.

First of all I have checked glide-report and removed 2 unused packages. Then I noticed gouuid and decided to re-implement it internally.

package main

import (
	"crypto/rand"
	"fmt"
)

func main() {
	fmt.Println(uuid())
	fmt.Println(uuid())
	fmt.Println(uuid())
}

func uuid() (string, error) {
	b := make([]byte, 16)
	_, err := rand.Read(b)

	if err != nil {
		return "", err
	}

	return fmt.Sprintf("%X-%X-%X-%X-%X", b[0:4], b[4:6], b[6:8], b[8:10], b[10:]), nil
}

Let’s run it:

go run test.go
2E395F0E-F422-1BD1-608F-C686D39A7DA1 <nil>
1C692140-0E15-8BCD-0738-1583115216A5 <nil>
652ED449-5085-BB13-0905-C5BD859E18A2 <nil>

I am satisfied of this result, though it’s a pseudo-uuid. Also benchmark result of this solution wins 3rd party dependency.

Think twice before go get!