generalize trigger kinds

daemon/job/trigger/periodic.go

@@ -0,0 +1,33 @@
+package trigger
+
+import (
+	"context"
+	"time"
+)
+
+type Periodic struct {
+	interval time.Duration
+}
+
+var _ Trigger = &Periodic{}
+
+func NewPeriodic(interval time.Duration) *Periodic {
+	return &Periodic{
+		interval: interval,
+	}
+}
+
+func (p *Periodic) ID() string { return "periodic" }
+
+func (p *Periodic) run(ctx context.Context, signal chan<- struct{}) {
+	t := time.NewTicker(p.interval)
+	defer t.Stop()
+	for {
+		select {
+		case <-t.C:
+			signal <- struct{}{}
+		case <-ctx.Done():
+			return
+		}
+	}
+}