*

.vscode/launch.json

@@ -11,6 +11,11 @@
       "mode": "debug",
       "program": "${workspaceRoot}/cmd/main.go",
       "env": {
+        "SMTP_HOST":"smtp.mail.ru",
+        // "SMTP_PORT":"465",
+        "SMTP_PORT":"587",
+        "SMTP_SENDER":"test3kbot@mail.ru",
+        "SMTP_PASSWORD":"hwNhMgPyBzMjwCj3hFPp",
         "KAFKA_PORT":"9092",
       },
       "args": []

internal/config/config.go

@@ -6,6 +6,13 @@ import (
 	"github.com/kelseyhightower/envconfig"
 )
 
+type smtpConfig struct {
+	Port     int    `envconfig:"SMTP_PORT"`
+	Host     string `envconfig:"SMTP_HOST"`
+	Sender   string `envconfig:"SMTP_SENDER"`
+	Password string `envconfig:"SMTP_PASSWORD"`
+}
+
 type kafkaConfig struct {
 	Host string `envconfig:"KAFKA_HOST"`
 	Port int    `envconfig:"KAFKA_PORT"`
@@ -13,6 +20,7 @@ type kafkaConfig struct {
 
 // ...
 type Config struct {
+	Smtp  smtpConfig
 	Kafka kafkaConfig
 }
 

internal/postman.go

@@ -2,22 +2,32 @@ package postman
 
 import (
 	"context"
+	"encoding/json"
 	"log"
 	"net"
 	"strconv"
 	"test3k/authPostman/internal/config"
 
+	smtp "test3k/authPostman/internal/smtp"
+
 	"github.com/segmentio/kafka-go"
 )
 
+type msg struct {
+	Code  string
+	Email string
+}
+
 type AuthPostmanServer struct {
 	ctx         context.Context
+	config      *config.Config
 	kafkaReader *kafka.Reader
 }
 
 func NewServer(ctx context.Context, config *config.Config, topic string) *AuthPostmanServer {
 	return &AuthPostmanServer{
-		ctx: ctx,
+		ctx:    ctx,
+		config: config,
 		kafkaReader: kafka.NewReader(kafka.ReaderConfig{
 			Topic:     topic,
 			Brokers:   []string{net.JoinHostPort(config.Kafka.Host, strconv.Itoa(config.Kafka.Port))},
@@ -44,6 +54,26 @@ func (s *AuthPostmanServer) ReadMessage(offset int64) error {
 			return err
 		}
 
-		log.Printf("message at offset %d: %s = %s\n", m.Offset, string(m.Key), string(m.Value))
+		// Декодируем сообщение
+		amsg := msg{}
+		erk := json.Unmarshal(m.Value, &amsg)
+		if erk != nil {
+			return erk
+		}
+
+		//
+		message := smtp.NewMessage("Confirmation code", amsg.Code)
+		message.AppendRecipient(amsg.Email)
+
+		//
+		smtpSender := smtp.NewService(s.config.Smtp.Host, s.config.Smtp.Port, s.config.Smtp.Sender, s.config.Smtp.Password)
+		ers := smtpSender.Send(message)
+		if ers != nil {
+			log.Print(ers)
+		}
+
+		//
+		// log.Printf("message at offset %d: %s = %s\n", m.Offset, string(m.Key), string(m.Value))
+		log.Printf("send code %v to %v", amsg.Code, amsg.Email)
 	}
 }

internal/smtp/attachment.go

@@ -0,0 +1,50 @@
+package postman
+
+import (
+	"bytes"
+	"encoding/base64"
+	"os"
+)
+
+// Вложение
+type Attachment struct {
+	name        string
+	contentType string
+	withFile    bool
+}
+
+func NewAttachment(file string) Attachment {
+	return Attachment{
+		name:        file,
+		contentType: "application/octet-stream",
+		withFile:    true,
+	}
+}
+
+// Импорт файла в тело письма
+func (a *Attachment) WriteFile(buffer *bytes.Buffer) error {
+	file, err := os.ReadFile(a.name)
+	if err != nil {
+		return err
+	}
+
+	//
+	payload := make([]byte, base64.StdEncoding.EncodedLen(len(file)))
+	base64.StdEncoding.Encode(payload, file)
+
+	//
+	buffer.WriteString("\r\n")
+
+	for index, line := 0, len(payload); index < line; index++ {
+		buffer.WriteByte(payload[index])
+
+		if (index+1)%76 == 0 {
+			_, era := buffer.WriteString("\r\n")
+			if era != nil {
+				return era
+			}
+		}
+	}
+
+	return nil
+}

internal/smtp/message.go

@@ -0,0 +1,35 @@
+package postman
+
+// Почтовое сообщения предназначенное для отправки
+type Message struct {
+	to          []string
+	subject     string
+	body        string
+	contentType string
+	attachments []Attachment
+}
+
+func NewMessage(subject string, body string) Message {
+	return Message{
+		to:          []string{},
+		subject:     subject,
+		contentType: "text/plain;charset=utf8",
+		attachments: []Attachment{},
+		body:        body,
+	}
+}
+
+// Пополнение списка получателей
+func (m *Message) AppendRecipient(recipient string) error {
+	m.to = append(m.to, recipient)
+
+	return nil
+}
+
+// Пополнение списка вложений
+func (m *Message) AppendAttachment(file string) error {
+	a := NewAttachment(file)
+	m.attachments = append(m.attachments, a)
+
+	return nil
+}

internal/smtp/smtp.go

@@ -0,0 +1,87 @@
+package postman
+
+import (
+	"bytes"
+	"errors"
+	"net/smtp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// SMTP сервис
+type Service struct {
+	user     string
+	password string
+	host     string
+	port     int
+}
+
+func NewService(host string, port int, sender string, password string) *Service {
+	return &Service{
+		user:     sender,
+		password: password,
+		host:     host,
+		port:     port,
+	}
+}
+
+// Отправка письма
+func (s *Service) Send(message Message) error {
+	if len(message.to) < 1 {
+		return errors.New("empty list of recipients")
+	}
+
+	//
+	auth := smtp.PlainAuth("", s.user, s.password, s.host)
+
+	//
+	buffer := bytes.NewBuffer(nil)
+	boundary := "GoBoundary"
+	headery := ""
+
+	// header
+	header := make(map[string]string)
+	header["From"] = s.user
+
+	header["To"] = message.to[0]
+	header["Cc"] = strings.Join(message.to[1:], ";")
+	header["Subject"] = message.subject
+	header["Content-Type"] = "multipart/mixed;boundary=" + boundary
+	header["Mime-Version"] = "1.0"
+	header["Date"] = time.Now().String()
+
+	for key, value := range header {
+		headery += key + ":" + value + "\r\n"
+	}
+
+	buffer.WriteString(headery + "\r\n")
+
+	// body
+	body := "\r\n--" + boundary + "\r\n"
+	body += "Content-Type:" + message.contentType + "\r\n"
+	body += "\r\n" + message.body + "\r\n"
+
+	buffer.WriteString(body)
+
+	// attachments
+	for _, x := range message.attachments {
+		if x.withFile {
+			attachment := "\r\n--" + boundary + "\r\n"
+			attachment += "Content-Transfer-Encoding:base64\r\n"
+			attachment += "Content-Disposition:attachment\r\n"
+			attachment += "Content-Type:" + x.contentType + ";name=\"" + x.name + "\"\r\n"
+
+			//
+			buffer.WriteString(attachment)
+
+			//
+			x.WriteFile(buffer)
+		}
+	}
+
+	buffer.WriteString("\r\n--" + boundary + "--")
+
+	// Sending message
+	return smtp.SendMail(s.host+":"+strconv.Itoa(s.port), auth, s.user, message.to, buffer.Bytes())
+}