Function Example_cronJob

example_cron_job_test.go:34–89

Example_cronJob demonstrates how to create a cron job with a more complex schedule using a third party cron package to parse more elaborate crontab syntax.

()

// schedule using a third party cron package to parse more elaborate crontab
// syntax.
func Example_cronJob() {
	ctx := context.Background()

	dbPool, err := pgxpool.New(ctx, riversharedtest.TestDatabaseURL())
	if err != nil {
		panic(err)
	}
	defer dbPool.Close()

	workers := river.NewWorkers()
	river.AddWorker(workers, &CronJobWorker{})

	schedule, err := cron.ParseStandard("30 * * * *") // every hour on the half hour
	if err != nil {
		panic(err)
	}

	riverClient, err := river.NewClient(riverpgxv5.New(dbPool), initTestConfig(ctx, dbPool, &river.Config{
		PeriodicJobs: []*river.PeriodicJob{
			river.NewPeriodicJob(
				schedule,
				func() (river.JobArgs, *river.InsertOpts) {
					return CronJobArgs{}, nil
				},
				&river.PeriodicJobOpts{RunOnStart: true},
			),
		},
		Queues: map[string]river.QueueConfig{
			river.QueueDefault: {MaxWorkers: 100},
		},
		Workers: workers,
	}))
	if err != nil {
		panic(err)
	}

	// Out of example scope, but used to wait until a job is worked.
	subscribeChan, subscribeCancel := riverClient.Subscribe(river.EventKindJobCompleted)
	defer subscribeCancel()

	// There's no need to explicitly insert a periodic job. One will be inserted
	// (and worked soon after) as the client starts up.
	if err := riverClient.Start(ctx); err != nil {
		panic(err)
	}

	// Wait for jobs to complete. Only needed for purposes of the example test.
	riversharedtest.WaitOrTimeoutN(testutil.PanicTB(), subscribeChan, 1)

	if err := riverClient.Stop(ctx); err != nil {
		panic(err)
	}

	// Output:
	// This job will run once immediately then every hour on the half hour
}