add scheduler

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

pkg/config/config.go

@@ -22,9 +22,10 @@ type Service struct {
 }
 
 type Check struct {
-	Name    string         `json:"name,omitempty" yaml:"name,omitempty"`
-	Data    string         `json:"data,omitempty" yaml:"data,omitempty"`
-	Timeout mtime.Duration `json:"timeout,omitempty" yaml:"timeout,omitempty"`
+	Name     string         `json:"name,omitempty" yaml:"name,omitempty"`
+	Data     string         `json:"data,omitempty" yaml:"data,omitempty"`
+	Timeout  mtime.Duration `json:"timeout,omitempty" yaml:"timeout,omitempty"`
+	Interval mtime.Duration `json:"interval,omitempty" yaml:"interval,omitempty"`
 }
 
 func (cfg *Config) Parse(r io.Reader) error {

pkg/scheduler/scheduler.go

@@ -0,0 +1,93 @@
+package scheduler
+
+import (
+	"time"
+
+	cron "github.com/go-co-op/gocron/v2"
+)
+
+type Task func()
+
+type Scheduler interface {
+	Start() error
+	Stop() error
+	Jobs() []Job
+	NewJob(td time.Duration, fn any, args ...any) (Job, error)
+}
+
+type Job interface {
+	ID() string
+	LastRun() (time.Time, error)
+	Name() string
+	NextRun() (time.Time, error)
+	NextRuns(int) ([]time.Time, error)
+}
+
+type Options struct{}
+
+type Option func(*Options) error
+
+type scheduler struct {
+	scheduler cron.Scheduler
+}
+
+func NewScheduler(opts ...Option) (Scheduler, error) {
+	s, err := cron.NewScheduler()
+	if err != nil {
+		return nil, err
+	}
+	return &scheduler{scheduler: s}, nil
+}
+
+func (s *scheduler) Start() error {
+	s.scheduler.Start()
+	return nil
+}
+
+func (s *scheduler) Stop() error {
+	if err := s.scheduler.Shutdown(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (s *scheduler) NewJob(td time.Duration, fn any, args ...any) (Job, error) {
+	j, err := s.scheduler.NewJob(cron.DurationJob(td), cron.NewTask(fn, args...))
+	if err != nil {
+		return nil, err
+	}
+	return &job{job: j}, nil
+}
+
+func (s *scheduler) Jobs() []Job {
+	jobs := s.scheduler.Jobs()
+	ret := make([]Job, len(jobs))
+	for idx := range jobs {
+		ret[idx] = &job{job: jobs[idx]}
+	}
+	return ret
+}
+
+type job struct {
+	job cron.Job
+}
+
+func (j *job) ID() string {
+	return j.job.ID().String()
+}
+
+func (j *job) LastRun() (time.Time, error) {
+	return j.job.LastRun()
+}
+
+func (j *job) Name() string {
+	return j.job.Name()
+}
+
+func (j *job) NextRun() (time.Time, error) {
+	return j.job.NextRun()
+}
+
+func (j *job) NextRuns(n int) ([]time.Time, error) {
+	return j.job.NextRuns(n)
+}