Go Language

Golang Cron Schedular Example

scheduler is a job scheduling package for Go. It provides a way to schedule the execution of the go function

Published · Dec 5 2019

Scheduler
scheduler is a job scheduling package for Go. It provides a simple, humans-friendly way to schedule the execution of the go function and includes delay and periodic.
Inspired by Linux cron and Python schedule.
Features
Delay execution, accurate to a second
Periodic execution, accurate to a second, like the cron style but more flexible
Cancel job
Failure retry
Installation
go get github.com/prprprus/scheduler

Example
job function
func task1(name string, age int) {
	fmt.Printf("run task1, with arguments: %s, %d\n", name, age)
}

func task2() {
	fmt.Println("run task2, without arguments")
}

Delay
Delayed supports four modes: seconds, minutes, hours, and days.
As a special case, the task will be executed immediately via s.Delay().Do(task) .
package main

import (
    "fmt"

    "github.com/prprprus/scheduler"
)

func main() {
	s, err := scheduler.NewScheduler(1000)
	if err != nil {
		panic(err) // just example
	}

	// delay with 1 second, job function with arguments
	s.Delay().Second(1).Do(task1, "prprprus", 23)

	// delay with 1 minute, job function without arguments
	s.Delay().Minute(1).Do(task2)

	// delay with 1 hour
	s.Delay().Hour(1).Do(task2)

	// special: execute immediately
	s.Delay().Do(task2)

	// cancel job
	jobID := s.Delay().Day(1).Do(task2)
	err = s.CancelJob(jobID)
	if err != nil {
		panic(err)
	} else {
		fmt.Println("cancel delay job success")
	}
}

Every
Like the cron style, it also includes seconds, minutes, hours, days, weekday, and months, but the order and number are not fixed. You can freely arrange and combine them according to your own preferences. For example, the effects of Second(3).Minute(35).Day(6) and Minute(35).Day(6).Second(3) are the same. No need to remember the format! 🎉👏

But for the readability, recommend the chronological order from small to large (or large to small).

Note: Day() and Weekday() avoid simultaneous occurrences unless you know that the day is the day of the week.

As a special case, the task will be executed once per second via s.Every().Do(task).
package main

import (
    "fmt"

    "github.com/prprprus/scheduler"
)

func main() {
	s, err := scheduler.NewScheduler(1000)
	if err != nil {
		panic(err)
	}

	// Specifies time to execute periodically
	s.Every().Second(45).Minute(20).Hour(13).Day(23).Weekday(3).Month(6).Do(task1, "prprprus", 23)
	s.Every().Second(15).Minute(40).Hour(16).Weekday(4).Do(task2)
	s.Every().Second(1).Do(task1, "prprprus", 23)

	// special: executed once per second
	s.Every().Do(task2)

	// cancel job
	jobID := s.Every().Second(1).Minute(1).Hour(1).Do(task2)
	err = s.CancelJob(jobID)
	if err != nil {
		panic(err)
	} else {
		fmt.Println("cancel periodically job success")
	}
}