lmyzzu / gocron

A Golang Job Scheduling Package.

This package is currently looking for new maintainers (cause @jasonlvhit is in ICU). Please message @jasonlvhit if you are interested.

goCron: A Golang Job Scheduling Package.

goCron is a Golang job scheduling package which lets you run Go functions periodically at pre-determined interval using a simple, human-friendly syntax.

goCron is a Golang implementation of Ruby module clockwork and Python job scheduling package schedule, and personally, this package is my first Golang program, just for fun and practice.

See also this two great articles:

• Rethinking Cron
• Replace Cron with Clockwork

Back to this package, you could just use this simple API as below, to run a cron scheduler.

package main

import (
	"fmt"
	"github.com/jasonlvhit/gocron"
)

func task() {
	fmt.Println("I am runnning task.")
}

func taskWithParams(a int, b string) {
	fmt.Println(a, b)
}

func main() {
	// Do jobs with params
	gocron.Every(1).Second().Do(taskWithParams, 1, "hello")
	
	// Do jobs safely, preventing an unexpected panic from bubbling up
	gocron.Every(1).Second().DoSafely(taskWithParams, 1, "hello")

	// Do jobs without params
	gocron.Every(1).Second().Do(task)
	gocron.Every(2).Seconds().Do(task)
	gocron.Every(1).Minute().Do(task)
	gocron.Every(2).Minutes().Do(task)
	gocron.Every(1).Hour().Do(task)
	gocron.Every(2).Hours().Do(task)
	gocron.Every(1).Day().Do(task)
	gocron.Every(2).Days().Do(task)

	// Do jobs on specific weekday
	gocron.Every(1).Monday().Do(task)
	gocron.Every(1).Thursday().Do(task)

	// function At() take a string like 'hour:min'
	gocron.Every(1).Day().At("10:30").Do(task)
	gocron.Every(1).Monday().At("18:30").Do(task)

	// remove, clear and next_run
	_, time := gocron.NextRun()
	fmt.Println(time)

	gocron.Remove(task)
	gocron.Clear()

	// function Start start all the pending jobs
	<- gocron.Start()

	// also, you can create a new scheduler
	// to run two schedulers concurrently
	s := gocron.NewScheduler()
	s.Every(3).Seconds().Do(task)
	<- s.Start()
}

and full test cases and document will be coming soon (help is wanted! If you want to contribute, pull requests are welcome).

If you need to prevent a job from running at the same time from multiple cron instances (like running a cron app from multiple servers), you can provide a Locker implementation and lock the required jobs.

gocron.SetLocker(lockerImplementation)
gocron.Every(1).Hour().Lock().Do(task)

Once again, thanks to the great works of Ruby clockwork and Python schedule package. BSD license is used, see the file License for detail.

Have fun!