How to Generate a UUID in Go

Using uuid Package

install

Use the following command to download the repository to the local file system.

Note that since Go 1.17 installing packages with go get is deprecated:

uuid Usage

The uuid package generates and inspects UUIDs based on RFC 4122 and DCE 1.1: Authentication and Security Services.

See the following example:

package main

import (
  "fmt"

  "github.com/google/uuid"
)

func main() {
  u := uuid.New()
  fmt.Println(u.String())
}

69b03ce1-ad12-4c98-a66d-861cc240f382

Using uuidgen Command

If you are on linux or mac, you can alternatively call /usr/bin/uuidgen.

The uuidgen program creates (and prints) a new universally unique identifier (UUID) using the libuuid(3) library.

For example,

package main

import (
  "fmt"
  "os/exec"
)

func main() {
  o, err := exec.Command("uuidgen").Output()
  if err != nil {
    // panic()
  }
  fmt.Printf("%s\n", o)
}

7b8cc5a3-f183-44b1-acb7-217eca047d43

Using uuid File

On Linux, you can read from /proc/sys/kernel/random/uuid:

package main

import (
  "fmt"
  "io/ioutil"
)

func main() {
  b, _ := ioutil.ReadFile("/proc/sys/kernel/random/uuid")
  fmt.Println(string(b))
}

051c9f24-afac-4d53-8aa5-64602a6c89bb

Using crypto Package

crypto/rand pkg implements a cryptographically secure random number generator. This doesn't comply to any standard 2.

Note: NOT RFC4122 compliant.

package main

import (
  "crypto/rand"
  "fmt"
)

// Note - NOT RFC4122 compliant
func uuid() string {
  b := make([]byte, 16)
  _, err := rand.Read(b)
  if err != nil {
    // panic()
    return ""
  }

  return fmt.Sprintf("%04x-%04x-%04x-%04x-%04x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:])
}

func main() {

  s := uuid()
  fmt.Println(s)
}

043ca19e-a8e7-b0f5-070f-8d7dbb240a19