Better token refresher

timer.go

package main

import (
	"log"
	"math/rand"
	"time"

	"github.com/google/uuid"
)

var token string

func main() {
	log.Println("Starting token worker")
	tokenReceiver := make(chan string)
	go tokenWorker(tokenReceiver)
	for {
		select {
		case val := <-tokenReceiver:
			log.Println("Received new AccessToken:", val)
			token = val
		}
	}
}

func tokenWorker(tokenReceiver chan string) {
	at := GetAccessToken()
	log.Println("Sending new token to receiver")
	tokenReceiver <- at.Token
	log.Println("Sleeping for", at.ExpiresIn)
	time.Sleep(at.ExpiresIn)
	go tokenWorker(tokenReceiver)
}

// GetAccessToken creates a stub AccessToken
func GetAccessToken() *AccessToken {
	u, _ := uuid.NewRandom()
	return &AccessToken{
		Token:     u.String(),
		ExpiresIn: time.Duration(rand.Int63n(5)) * time.Second,
	}
}

// AccessToken represents a token that can be used to authenticate with a REST API
type AccessToken struct {
	Token     string
	ExpiresIn time.Duration
}