add notify model, add send notify method

settings.go

@@ -12,6 +12,15 @@ type Domain struct {
 	SubDomains []string `json:"sub_domains"`
 }
 
+type Notify struct {
+	Enabled    bool   `json:"enabled"`
+	SMTPServer string `json:"smtp_server"`
+	SendTo     string `json:"send_to"`
+	Port       int    `json:"port"`
+	Account    string `json:"account"`
+	Password   string `json:"password"`
+}
+
 // Settings struct
 type Settings struct {
 	Provider    string   `json:"provider"`
@@ -22,6 +31,7 @@ type Settings struct {
 	IPUrl       string   `json:"ip_url"`
 	LogPath     string   `json:"log_path"`
 	Socks5Proxy string   `json:"socks5_proxy"`
+	Notify      Notify   `json:"notify"`
 }
 
 // LoadSettings -- Load settings from config file

utils.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"golang.org/x/net/proxy"
+	"gopkg.in/gomail.v2"
 )
 
 var (
@@ -102,3 +103,21 @@ func LoadCurrentIP() string {
 
 	return strings.Replace(string(content), "\n", "", -1)
 }
+
+// SendNotify sends mail notify if IP is changed
+func SendNotify(configuration *Settings, currentIP string) error {
+	m := gomail.NewMessage()
+
+	m.SetHeader("From", configuration.Notify.Account)
+	m.SetHeader("To", configuration.Notify.SendTo)
+	m.SetHeader("Subject", "GoDNS Notification")
+	m.SetBody("text/html", "")
+
+	d := gomail.NewPlainDialer(configuration.Notify.SMTPServer, configuration.Notify.Port, configuration.Notify.Account, configuration.Notify.Password)
+
+	// Send the email config by sendlist	.
+	if err := d.DialAndSend(m); err != nil {
+		return err
+	}
+	return nil
+}