app/task/task.go

package task

import (
	"fmt"
	"time"

	cron "github.com/robfig/cron/v3"
	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"
)

var l zerolog.Logger
var clog = mylogger{}
var c *cron.Cron

func init() {
	// viper.Set("task.runner", 5)
}

func Init() {
	l = log.With().Str("mod", "task").Logger()
	c = cron.New(
		cron.WithLogger(&clog),
		cron.WithChain(func(j cron.Job) cron.Job {
			t, ok := j.(*_task)
			if ok {
				l.Debug().Str("taskid", t.Task.ID).Msg("")
			}
			return j
		}),
		cron.WithLocation(time.Local))
}

type Task struct {
	ID          string
	Description string
	Group       string

	// Func is the stored function that will be called with the args,
	// and a interface to carry value will be provided as the first argument
	// args will be passed after carry, in order to normalize,
	// it is suggested to use strings or other simple types
	Func func(c *interface{}, args ...interface{}) error `json:"-"`
}

type _task struct {
	Task *Task
	name string
	id   cron.EntryID
	args []interface{}
	spec string
	once bool
	// carry value to the next run. Should be modified from the Task.Func
	carry *interface{}
}

func (t *_task) Run() {
	if t.carry == nil {
		t.carry = new(interface{})
	}
	defer func() {
		if err := recover(); err != nil {
			l.Error().Str("error", fmt.Sprint(err)).Msg("")
		} else if t.once {
			c.Remove(t.id)
		}
	}()
	l.Info().Str("task_id", t.Task.ID).
		Str("task name", t.name).
		Msg("task started.")
	err := t.Task.Func(t.carry, t.args...)
	if err != nil {
		l.Error().Err(err).Str("task_id", t.Task.ID).
			Str("task name", t.name).Msg("task error")
	}
	Reporter <- &Report{
		Entry:       t.id,
		ID:          t.Task.ID,
		Description: t.Task.Description,
		Group:       t.Task.Group,
		Name:        t.name,
		Spec:        t.spec,
		Once:        t.once,
		Args:        t.args,
		Carry:       t.carry,
		Error:       err,
	}

}

func Start() {
	if len(started) == 1 {
		return
	}
	started <- struct{}{}
	c.Start()
	go func() {
		for {
			select {
			case r := <-Reporter:
				wg.Add(1)
				ReportReceiver(r)
				wg.Done()
			case <-quit:
				<-started
				return
			}
		}
	}()
}

func Stop() {
	if len(started) == 0 {
		return
	}
	quit <- struct{}{}
	<-c.Stop().Done()
	wg.Wait()
}