diff --git a/coolDns.go b/coolDns.go
index c129870..b891d69 100644
--- a/coolDns.go
+++ b/coolDns.go
@@ -76,6 +76,47 @@ var anyRecordTypes = []uint16{
 	dns.TypeCAA,
 }
 
+func start(configPath string) {
+	config, err := loadConfig(configPath)
+	if err != nil {
+		log.Fatalf("Failed to load config: %s\n", err.Error())
+	}
+
+	err = os.Chdir(filepath.Dir(configPath))
+	if err != nil {
+		log.Fatalf("Failed to goto config dir: %s", err.Error())
+	}
+
+	zones, err := loadZones(config.Zones)
+	if err != nil {
+		log.Fatalf("Failed to load zones: %s\n", err.Error())
+	}
+
+	aclList, err := createACLList(config.ACL)
+	if err != nil {
+		log.Fatalf("Failed to parse ACL rules: %s\n", err.Error())
+	}
+
+	blacklist := loadBlacklist(config.Blacklist)
+
+	var acmeMap *legoMap
+	if config.Lego.Enable {
+		acmeMap = startLEGOWebSever(config.Lego)
+	}
+
+	server := createServer(zones, *config, aclList, blacklist, acmeMap)
+
+	listenAndServer(server, config.Address)
+
+	if config.TLS.Enable {
+		listenAndServerTLS(server, config.TLS.Address, config.TLS.Cert, config.TLS.Key)
+
+		log.Printf("Start listening on tcp %s for tls", config.TLS.Address)
+	}
+
+	log.Printf("Start listening on udp %s and tcp %s\n", config.Address, config.Address)
+}
+
 func loadConfig(configPath string) (*config, error) {
 	file, err := ioutil.ReadFile(configPath)
 	if err != nil {
@@ -384,44 +425,7 @@ func main() {
 	configPath := flag.String("c", "/etc/cool-dns/config.yaml", "path to the config file")
 	flag.Parse()
 
-	config, err := loadConfig(*configPath)
-	if err != nil {
-		log.Fatalf("Failed to load config: %s\n", err.Error())
-	}
-
-	err = os.Chdir(filepath.Dir(*configPath))
-	if err != nil {
-		log.Fatalf("Failed to goto config dir: %s", err.Error())
-	}
-
-	zones, err := loadZones(config.Zones)
-	if err != nil {
-		log.Fatalf("Failed to load zones: %s\n", err.Error())
-	}
-
-	aclList, err := createACLList(config.ACL)
-	if err != nil {
-		log.Fatalf("Failed to parse ACL rules: %s\n", err.Error())
-	}
-
-	blacklist := loadBlacklist(config.Blacklist)
-
-	var acmeMap *legoMap
-	if config.Lego.Enable {
-		acmeMap = startLEGOWebSever(config.Lego)
-	}
-
-	server := createServer(zones, *config, aclList, blacklist, acmeMap)
-
-	listenAndServer(server, config.Address)
-
-	if config.TLS.Enable {
-		listenAndServerTLS(server, config.TLS.Address, config.TLS.Cert, config.TLS.Key)
-
-		log.Printf("Start listening on tcp %s for tls", config.TLS.Address)
-	}
-
-	log.Printf("Start listening on udp %s and tcp %s\n", config.Address, config.Address)
+	start(*configPath)
 
 	sig := make(chan os.Signal)
 	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)