cml04-mediciones-service/internal/app/app.go

package app

import (
	"context"
	"flag"
	"os"
	"os/signal"
	"syscall"

	cml04eventer "git.espin.casa/albert/cml04-eventer"
	"git.espin.casa/albert/cml04-mediciones-service/internal/logging"
	"git.espin.casa/albert/cml04-mediciones-service/internal/server"
	"git.espin.casa/albert/cml04-mediciones-service/internal/service"
	"git.espin.casa/albert/cml04-mediciones-service/internal/storage"
	"git.espin.casa/albert/logger"
)

const (
	Topic string = "SAP-IN"
)

func Run() error {
	// flags
	bindAddr := flag.String("bind-addr", ":3000", "http rest api bind address")
	dbUser := flag.String("db-user", "mediciones", "database username")
	dbPass := flag.String("db-user-pass", "mediciones", "database user password")
	dbHost := flag.String("db-host", "10.1.152.13", "database host server")
	dbPort := flag.String("db-port", "3308", "database host port")
	dbName := flag.String("db-name", "mediciones", "database name")
	nsqHost := flag.String("nsq-host", "10.1.152.13", "NSQ host")
	nsqPort := flag.Int("nsq-port", 4150, "NSQ port")
	logLevel := flag.String("level", "debug", "Log level")
	// parse flags
	flag.Parse()
	// log fields
	logFields := logger.LogFields{
		"bind_address": *bindAddr,
		"log_level":    *logLevel,
		"db_host":      *dbHost,
		"db_port":      *dbPort,
		"db_name":      *dbName,
		"nsq_host":     *nsqHost,
		"nsq_port":     *nsqPort,
	}
	// setup logger
	log := logger.New(os.Stdout, *logLevel)
	// create storage
	storage, err := storage.NewStorage(&storage.StorageConfig{
		User:   *dbUser,
		Pass:   *dbPass,
		Host:   *dbHost,
		Port:   *dbPort,
		DBName: *dbName,
	})
	if err != nil {
		log.Error("create storage failed", err, logFields)
		return err
	}
	// create subscriber
	subscriber, err := cml04eventer.NewSubscriber(&cml04eventer.SubscriberConfig{
		NSQAddress:  *nsqHost,
		NSQPort:     *nsqPort,
		Unmarshaler: cml04eventer.JSONMarshaler{},
		Channel:     "CML04-MEDICIONES",
	}, log)
	// handle error
	if err != nil {
		log.Error("create subscriber failed", err, logFields)
		return err
	}
	// close subscriber graceful
	defer subscriber.Close()
	// create service
	svc := service.NewService(storage)
	// create logging service
	svc = logging.NewLoggingService(log, svc)
	// create server
	server := server.NewServer(*bindAddr, svc)
	// create context
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	// subscribe event bus
	eventChann, err := subscriber.SubscribeEvent(ctx, Topic)
	// handle error
	if err != nil {
		log.Error("subscribe event failed", err, logFields)
		return err
	}
	// process incoming events
	go func() {
		for event := range eventChann {
			if err := svc.ProcessEvent(ctx, event); err != nil {
				log.Error("process event has been failed", err, logFields)
				continue
			}
		}
	}()
	// start server
	server.Start()
	// info banner
	log.Info("started cml04-mediciones-service *", logFields)
	// wait signal to finish
	signal := WaitSignal()
	log.Info("signal received", logFields.Add(logger.LogFields.Add(logFields, logger.LogFields{
		"signal": signal,
	})))
	return nil
}

// WaitSignal catching exit signal
func WaitSignal() os.Signal {
	ch := make(chan os.Signal, 2)
	signal.Notify(
		ch,
		syscall.SIGINT,
		syscall.SIGQUIT,
		syscall.SIGTERM,
	)
	for {
		sig := <-ch
		switch sig {
		case syscall.SIGINT, syscall.SIGQUIT, syscall.SIGTERM:
			return sig
		}
	}
}