Using Goroutines to run a poor mans Cron Job

03 Nov, 2021

Lately, I wanted to push some stuff to a statsD server from within a golang application, without setting up a whole new init for a cron job.

Turns out, it's pretty easy when you're using goroutines to get that working.

func Start() chan bool {
    ticker := time.NewTicker(10 * time.Minute)
    quit := make(chan bool, 1)

    go func() {
    	for {
    		select {
    		case <-ticker.C:
    			report()
    		case <-quit:
    			ticker.Stop()
    		}
    	}
    }()

    return quit
}

func report() {
    // do your thing here
}

Explanation

• You'd initiate a Ticker first. Timers are for when you want to do something once in the future - _tickers_ are for when you want to do something repeatedly at regular intervals - GoByExample.
• You'd make a channel chan, that you can close() later on. This will help us stop the ticker gracefully when the main thread stops.
• Initiate your goroutine, as you'd do normally with go func()
• Use the for by select combo, which allows you to wait on multiple channel operations repeatedly.
  • ticker.C gives us a chan of time.Time
  • quit gives us a chan of bool
  • Using these two, we can invoke report() gracefully.

Sidenotes

• Don't forget to utilise the returning chan bool when you're calling Start() to gracefully shut down the ticker.

#programming #golang