Task scheduling

// routes/schedule.go, passed to vukem.WithSchedule by bootstrap
func Schedule(s *schedule.Schedule, app *vukem.App) {
	s.Command("reports:send", "--daily").DailyAt("08:00").WithoutOverlapping()
	s.Job(jobs.PruneSessions{}).Hourly()
	s.Func("ping", func(ctx context.Context) error { ... }).EveryFiveMinutes()
	s.Func("invoices", sendInvoices).Cron("30 9 1 * *").In(saoPaulo)
}

Frequencies#

Cron expressions support *, values, ranges, steps (*/15, 10-50/20), lists, JAN/MON names and @hourly, @daily, @weekly, @monthly, @yearly. When both day fields are set, a day matches either (Vixie cron). A bad expression panics at boot; the parser is fuzzed.

Time zones and overlap#

• SCHEDULE_TIMEZONE (IANA name, default UTC) applies to every task; .In(loc) overrides one. The zone database is embedded, so it works on Windows hosts without one.
• WithoutOverlapping() skips a run while the previous one still holds its lock (released when it ends, or after 24h). Locks use app.Cache(): set CACHE_STORE=database or use Redis when several servers run the schedule.

Running it#

vukem schedule:work    # in process: ticks at the start of every minute
vukem schedule:list    # each task and its next run

Or one crontab entry calling schedule:run every minute:

* * * * * cd /srv/app && ./app schedule:run

Tasks due at the same minute run concurrently; failures and panics are logged and do not stop the others. Command tasks run in the same process through app.Call.