Chronos - scheduled tasks for golang

Chronos is a library for scheduling tasks under a given scheduling plan. It supports scheduling of monthly, weekly, daily tasks or at a specific date or after a given duration. It is similar to the cron service on linux.

Usage

Notes:

• The task's Start() function is non blocking.
• The defined action is executed in a separate goroutine.

Schedule

Daily:

// each day on 4:30, 10:45, 12:30
plan := NewDailySchedulingPlan([]DayTime{
   {4, 20, 0}, 
   {10, 45, 0}, 
   {12, 30},
})

task := NewScheduledTask(func() {
      ...
}, plan)
defer task.Stop()

// start the task
task.Start()

Weekly:

// on monday at 12, on friday twice at 9 am and 3 pm, once at sunday at 7 pm
plan := NewWeeklySchedulingPlan([]DayTime{
      {Day: time.Monday, At: DayTime{12, 0, 0},
      {Day: time.Friday, At: DayTime{9, 0, 0},
      {Day: time.Friday, At: DayTime{15, 0, 0},
      {Day: time.Sunday, At: DayTime{19, 0, 0},
})

task := NewScheduledTask(func() {
      ...
}, plan)
defer task.Stop()

// start the task
task.Start()

Monthly:

// on the 12th at 4:30 pm, 20th at 6 pm and 9 pm, 31th on 9 am
// NOTE: the 31th auto. shrinks to 28, 29 (February with leap year) or 30
plan := NewMonthlySchedulingPlan([]MonthDay{
      {Day: 12, At: DayTime{16, 30, 0},
      {Day: 20, At: DayTime{18, 0, 0},
      {Day: 20, At: DayTime{21, 0, 0},
      {Day: 31, At: DayTime{9, 0, 0},
})

task := NewScheduledTask(func() {
      ...
}, plan)
defer task.Stop()

// start the task
task.Start()

Once

at a given date:

// once on the 29th of November at 3 pm
plan := NewOnceAtDatePlan(time.Date(2017, time.November, 29, 15, 0, 0, 0, time.Local))

task := NewScheduledTask(func() {
      ...
}, plan)
defer task.Stop()

// start the task
task.Start()

after a given duration (essentially the same as doing time.After(d time.Duration)):

// once after 5 seconds
plan := NewOnceAfterDuration(time.Duration(5) * time.Second)

task := NewScheduledTask(func() {
      ...
}, plan)
defer task.Stop()

// start the task
task.Start()

Persistence

Use the simple FileStorage to save the schedule to disk and to initialize the task back on startup.

storage := NewFileStorage("./", "schedule.json")
planFromDisk, err := storage.LoadSchedule()
if err != nil {
    ...
}

// re-create the task with the plan loaded from disk
task := NewScheduledTask(func(){
    ...
}, planFromDisk)