refactor: separate SMTP config from LDAP struct

The LDAP struct was mixing LDAP connection settings with unrelated mail
settings. Extract mail fields into a dedicated SMTPConfig struct with
its own global (mySMTP), keeping concerns cleanly separated.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ldap.go

@@ -21,11 +21,14 @@ type LDAP struct {
 	BaseDN          string
 	ServiceDN       string
 	ServicePassword string
-	MailHost        string
-	MailPort        int
-	MailUser        string
-	MailPassword    string
-	MailFrom        string
+}
+
+type SMTPConfig struct {
+	MailHost     string
+	MailPort     int
+	MailUser     string
+	MailPassword string
+	MailFrom     string
 }
 
 func (l LDAP) Connect() (*LDAPConn, error) {

lost.go

@@ -167,14 +167,14 @@ func lostPassword(w http.ResponseWriter, r *http.Request) {
 
 	// Send the email
 	m := gomail.NewMessage()
-	m.SetHeader("From", myLDAP.MailFrom)
+	m.SetHeader("From", mySMTP.MailFrom)
 	m.SetHeader("To", email)
 	m.SetHeader("Subject", "SSO nemunai.re: password recovery")
 	m.SetBody("text/plain", "Hello "+cn+"!\n\nSomeone, and we hope it's you, requested to reset your account password. \nIn order to continue, go to:\n"+myPublicURL+"/reset?l="+r.PostFormValue("login")+"&t="+token+"\n\nThis link expires in 1 hour and can only be used once.\n\nBest regards,\n-- \nnemunai.re SSO")
 
 	var s gomail.Sender
-	if myLDAP.MailHost != "" {
-		d := gomail.NewDialer(myLDAP.MailHost, myLDAP.MailPort, myLDAP.MailUser, myLDAP.MailPassword)
+	if mySMTP.MailHost != "" {
+		d := gomail.NewDialer(mySMTP.MailHost, mySMTP.MailPort, mySMTP.MailUser, mySMTP.MailPassword)
 		s, err = d.Dial()
 		if err != nil {
 			log.Println("Unable to connect to email server: " + err.Error())

main.go

@@ -31,9 +31,12 @@ var dockerRegistrySecret string
 var allowedAliasDomains []string
 
 var myLDAP = LDAP{
-	Host:     "localhost",
-	Port:     389,
-	BaseDN:   "dc=example,dc=com",
+	Host:   "localhost",
+	Port:   389,
+	BaseDN: "dc=example,dc=com",
+}
+
+var mySMTP = SMTPConfig{
 	MailPort: 587,
 	MailFrom: "noreply@example.com",
 }
@@ -115,8 +118,13 @@ func main() {
 			log.Fatal(err)
 		} else if cnt, err := io.ReadAll(fd); err != nil {
 			log.Fatal(err)
-		} else if err := json.Unmarshal(cnt, &myLDAP); err != nil {
-			log.Fatal(err)
+		} else {
+			if err := json.Unmarshal(cnt, &myLDAP); err != nil {
+				log.Fatal(err)
+			}
+			if err := json.Unmarshal(cnt, &mySMTP); err != nil {
+				log.Fatal(err)
+			}
 		}
 	}
 
@@ -156,17 +164,17 @@ func main() {
 	}
 
 	if val, ok := os.LookupEnv("SMTP_HOST"); ok {
-		myLDAP.MailHost = val
+		mySMTP.MailHost = val
 	}
 	if val, ok := os.LookupEnv("SMTP_PORT"); ok {
 		if port, err := strconv.Atoi(val); err == nil {
-			myLDAP.MailPort = port
+			mySMTP.MailPort = port
 		} else {
 			log.Println("Invalid value for SMTP_PORT:", val)
 		}
 	}
 	if val, ok := os.LookupEnv("SMTP_USER"); ok {
-		myLDAP.MailUser = val
+		mySMTP.MailUser = val
 	}
 	if val, ok := os.LookupEnv("SMTP_PASSWORD_FILE"); ok {
 		if fd, err := os.Open(val); err != nil {
@@ -176,13 +184,13 @@ func main() {
 			log.Fatal(err)
 		} else {
 			fd.Close()
-			myLDAP.MailPassword = string(cnt)
+			mySMTP.MailPassword = string(cnt)
 		}
 	} else if val, ok := os.LookupEnv("SMTP_PASSWORD"); ok {
-		myLDAP.MailPassword = val
+		mySMTP.MailPassword = val
 	}
 	if val, ok := os.LookupEnv("SMTP_FROM"); ok {
-		myLDAP.MailFrom = val
+		mySMTP.MailFrom = val
 	}
 	if val, ok := os.LookupEnv("PUBLIC_URL"); ok {
 		myPublicURL = val