tsk-3: Create async loop (#4)

Closes #3

Reviewed-on: #4
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

Makefile

@@ -6,16 +6,17 @@ GO_VERSION ?= $(shell go version | awk '{print $$3}')
 .PHONY: build
 build:
 	go build -ldflags="\
-		-X 'git.kundeng.us/phoenix/catapult/version.Version=$(VERSION)' \
-		-X 'git.kundeng.us/phoenix/catapult/version.BuildTime=$(BUILD_TIME)' \
-		-X 'git.kundeng.us/phoenix/catapult/version.Commit=$(COMMIT)' \
-		-X 'git.kundeng.us/phoenix/catapult/version.GoVersion=$(GO_VERSION)'" \
-		-o catapult main.go
+		-X 'git.kundeng.us/phoenix/catapult/internal/version.Version=$(VERSION)' \
+		-X 'git.kundeng.us/phoenix/catapult/internal/version.BuildTime=$(BUILD_TIME)' \
+		-X 'git.kundeng.us/phoenix/catapult/internal/version.Commit=$(COMMIT)' \
+		-X 'git.kundeng.us/phoenix/catapult/internal/version.GoVersion=$(GO_VERSION)'" \
+		-o catapult cmd/catapult/main.go
 
 .PHONY: install
 install:
 	go install -ldflags="\
-		-X 'git.kundeng.us/phoenix/catapult/version.Version=$(VERSION)' \
-		-X 'git.kundeng.us/phoenix/catapult/version.BuildTime=$(BUILD_TIME)' \
-		-X 'git.kundeng.us/phoenix/catapult/version.Commit=$(COMMIT)' \
-		-X 'git.kundeng.us/phoenix/catapult/version.GoVersion=$(GO_VERSION)'"
+		-X 'git.kundeng.us/phoenix/catapult/internal/version.Version=$(VERSION)' \
+		-X 'git.kundeng.us/phoenix/catapult/internal/version.BuildTime=$(BUILD_TIME)' \
+		-X 'git.kundeng.us/phoenix/catapult/internal/version.Commit=$(COMMIT)' \
+		-X 'git.kundeng.us/phoenix/catapult/internal/version.GoVersion=$(GO_VERSION)'"
+		-o catapult cmd/catapult/main.go

cmd/catapult/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"git.kundeng.us/phoenix/catapult/internal/config"
+	"git.kundeng.us/phoenix/catapult/internal/version"
+)
+
+func main() {
+	fmt.Println(config.App_Name)
+
+	versionFlag := config.CheckVersionFlag()
+	if *versionFlag {
+		fmt.Println(version.String())
+		return
+	}
+
+	service := config.NewService()
+
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+
+	service.Start()
+
+	<-sigChan
+	service.Stop()
+}

internal/config/config.go

@@ -0,0 +1,102 @@
+package config
+
+import (
+	"context"
+	"flag"
+	"log"
+	"sync"
+	"time"
+)
+
+const App_Name = "catapult"
+
+func CheckVersionFlag() *bool {
+	versionFlag := flag.Bool("version", false, "Print version information")
+	flag.Parse()
+
+	return versionFlag
+}
+
+type Service struct {
+	wg     sync.WaitGroup
+	ctx    context.Context
+	cancel context.CancelFunc
+}
+
+func NewService() *Service {
+	ctx, cancel := context.WithCancel(context.Background())
+	return &Service{
+		ctx:    ctx,
+		cancel: cancel,
+	}
+}
+
+func (s *Service) Start() {
+	log.Println("Starting service...")
+
+	// Start multiple background workers
+	s.wg.Add(3)
+	go s.worker1()
+	go s.worker2()
+	go s.healthChecker()
+}
+
+func (s *Service) worker1() {
+	defer s.wg.Done()
+
+	ticker := time.NewTicker(5 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-s.ctx.Done():
+			log.Println("Worker 1 shutting down...")
+			return
+		case <-ticker.C:
+			// Do some work
+			log.Println("Worker 1: Processing...")
+		}
+	}
+}
+
+func (s *Service) worker2() {
+	defer s.wg.Done()
+
+	ticker := time.NewTicker(10 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-s.ctx.Done():
+			log.Println("Worker 2 shutting down...")
+			return
+		case <-ticker.C:
+			// Do some work
+			log.Println("Worker 2: Processing...")
+		}
+	}
+}
+
+func (s *Service) healthChecker() {
+	defer s.wg.Done()
+
+	ticker := time.NewTicker(30 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-s.ctx.Done():
+			log.Println("Health checker shutting down...")
+			return
+		case <-ticker.C:
+			log.Println("Health check: Service is healthy")
+		}
+	}
+}
+
+func (s *Service) Stop() {
+	log.Println("Shutting down service...")
+	s.cancel()
+	s.wg.Wait()
+	log.Println("Service stopped gracefully")
+}

main.go

@@ -1,22 +0,0 @@
-package main
-
-import (
-	"flag"
-	"fmt"
-
-	"git.kundeng.us/phoenix/catapult/internal/version"
-)
-
-const App_Name = "catapult"
-
-func main() {
-	fmt.Println(App_Name)
-
-	versionFlag := flag.Bool("version", false, "Print version information")
-	flag.Parse()
-
-	if *versionFlag {
-		fmt.Println(version.String())
-		return
-	}
-}