📚 gron - Awesome Go Library for Job Scheduler
Define time-based tasks using a simple Go API and Gron’s scheduler will run them accordingly.
Detailed Description of gron
gron
Gron provides a clear syntax for writing and deploying cron jobs.
Goals
- Minimalist APIs for scheduling jobs.
- Thread safety.
- Customizable Job Type.
- Customizable Schedule.
Installation
$ go get github.com/roylee0704/gron
Usage
Create schedule.go
package main
import (
"fmt"
"time"
"github.com/roylee0704/gron"
)
func main() {
c := gron.New()
c.AddFunc(gron.Every(1*time.Hour), func() {
fmt.Println("runs every hour.")
})
c.Start()
}
Schedule Parameters
All scheduling is done in the machine's local time zone (as provided by the Go time package).
Setup basic periodic schedule with gron.Every()
.
gron.Every(1*time.Second)
gron.Every(1*time.Minute)
gron.Every(1*time.Hour)
Also support Day
, Week
by importing gron/xtime
:
import "github.com/roylee0704/gron/xtime"
gron.Every(1 * xtime.Day)
gron.Every(1 * xtime.Week)
Schedule to run at specific time with .At(hh:mm)
gron.Every(30 * xtime.Day).At("00:00")
gron.Every(1 * xtime.Week).At("23:59")
Custom Job Type
You may define custom job types by implementing gron.Job
interface: Run()
.
For example:
type Reminder struct {
Msg string
}
func (r Reminder) Run() {
fmt.Println(r.Msg)
}
After job has defined, instantiate it and schedule to run in Gron.
c := gron.New()
r := Reminder{ "Feed the baby!" }
c.Add(gron.Every(8*time.Hour), r)
c.Start()
Custom Job Func
You may register Funcs
to be executed on a given schedule. Gron will run them in their own goroutines, asynchronously.
c := gron.New()
c.AddFunc(gron.Every(1*time.Second), func() {
fmt.Println("runs every second")
})
c.Start()
Custom Schedule
Schedule is the interface that wraps the basic Next
method: Next(p time.Duration) time.Time
In gron
, the interface value Schedule
has the following concrete types:
- periodicSchedule. adds time instant t to underlying period p.
- atSchedule. reoccurs every period p, at time components(hh:mm).
For more info, checkout schedule.go
.
Full Example
package main
import (
"fmt"
"github.com/roylee0704/gron"
"github.com/roylee0704/gron/xtime"
)
type PrintJob struct{ Msg string }
func (p PrintJob) Run() {
fmt.Println(p.Msg)
}
func main() {
var (
// schedules
daily = gron.Every(1 * xtime.Day)
weekly = gron.Every(1 * xtime.Week)
monthly = gron.Every(30 * xtime.Day)
yearly = gron.Every(365 * xtime.Day)
// contrived jobs
purgeTask = func() { fmt.Println("purge aged records") }
printFoo = printJob{"Foo"}
printBar = printJob{"Bar"}
)
c := gron.New()
c.Add(daily.At("12:30"), printFoo)
c.AddFunc(weekly, func() { fmt.Println("Every week") })
c.Start()
// Jobs may also be added to a running Gron
c.Add(monthly, printBar)
c.AddFunc(yearly, purgeTask)
// Stop Gron (running jobs are not halted).
c.Stop()
}