overflow_probes/probe/probe.go

package probe

import (
	"context"
	"sync"

	cdr "git.loafle.net/commons_go/di/registry"
	"git.loafle.net/commons_go/logging"
	crr "git.loafle.net/commons_go/rpc/registry"
	oocmci "git.loafle.net/overflow/overflow_commons_go/modules/commons/interfaces"
	oocmp "git.loafle.net/overflow/overflow_commons_go/modules/probe"
	oocu "git.loafle.net/overflow/overflow_commons_go/util"
	oogwc "git.loafle.net/overflow/overflow_gateway_websocket/client"
	oopccd "git.loafle.net/overflow/overflow_probes/client/central/data"
	oopccp "git.loafle.net/overflow/overflow_probes/client/central/probe"
	oopca "git.loafle.net/overflow/overflow_probes/commons/annotation"
	"git.loafle.net/overflow/overflow_probes/service"
)

func New() ProbeManager {
	a := &probeManagers{}

	return a
}

type ProbeManager interface {
	oocmci.Starter
	oocmci.Stopper
}

type probeManagers struct {
	stopChan chan struct{}
	stopWg   sync.WaitGroup
}

func (pm *probeManagers) Start() error {
	if nil != pm.stopChan {
		logging.Logger().Panicf("Probe: already running. Stop it before starting it again")
	}

	service.InitService()

	probeRPCRegistry := crr.NewRPCRegistry()

	centralProbeClient := oopccp.New(probeRPCRegistry)
	centralDataClient := oopccd.New()
	centralClients := map[string]oogwc.Client{
		oocmp.HTTPEntry_Probe: centralProbeClient,
		oocmp.HTTPEntry_Data:  centralDataClient,
	}
	cdr.RegisterResource("CentralClients", centralClients)
	cdr.RegisterResource("ProbeRPCInvoker", probeRPCRegistry)

	var (
		services []interface{}
		err      error
	)

	services, err = cdr.GetInstancesByAnnotationName(oopca.ServiceTag)
	if nil != err {
		logging.Logger().Panicf("Probe: Cannot create instances of service %v", err)
	}

	for _, s := range services {
		probeRPCRegistry.RegisterService(s, "")
	}

	pm.stopChan = make(chan struct{})

	pm.stopWg.Add(1)
	go pm.handleProbe(services)

	return nil
}

func (pm *probeManagers) Stop(ctx context.Context) error {
	if pm.stopChan == nil {
		logging.Logger().Warnf("Probe: probe must be started before stopping it")
	}
	close(pm.stopChan)
	pm.stopWg.Wait()
	pm.stopChan = nil

	// pm.cClient.Close()

	logging.Logger().Infof("Probe: stopped")

	return nil
}

func (pm *probeManagers) handleProbe(services []interface{}) {
	var (
		err error
	)

	err = oocu.ExecuteStarters(services, service.ServicesToStartAndStop, false)
	if nil != err {
		logging.Logger().Panic(err)
	}

	defer func() {
		err = oocu.ExecuteStoppers(services, service.ServicesToStartAndStop, true)
		if nil != err {
			logging.Logger().Error(err)
		}

		pm.stopWg.Done()

		pm.Stop(nil)
	}()

	for {
		select {
		case <-pm.stopChan:
			return
		}
	}
}