move structs in right packages + impl sender service to build and send e-mail

config/smtp.go

@@ -0,0 +1,43 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+)
+
+// mandatory parameters for the STMP server connection
+type SMTPConfig struct {
+	User     string
+	Password string
+	Url      string
+	Port     string
+}
+
+func NewSMTPConfig(user, password, url, port string) (SMTPConfig, error) {
+	var config SMTPConfig
+	if user == "" {
+		return config, errors.New("SMTP user can't be empty")
+	}
+	config.User = user
+
+	if password == "" {
+		return config, errors.New("SMTP password can't be empty")
+	}
+	config.Password = password
+
+	if url == "" {
+		return config, errors.New("SMTP server url can't be empty")
+	}
+	config.Url = url
+
+	if port == "" {
+		return config, errors.New("SMTP server port can't be empty")
+	}
+	config.Port = port
+
+	return config, nil
+}
+
+func (c SMTPConfig) GetFullUrl() string {
+	return fmt.Sprintf("%s:%s", c.Url, c.Port)
+}

mail/mail.go

@@ -0,0 +1,49 @@
+package mail
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"strings"
+)
+
+type Email struct {
+	Sender    string   `json:"sender"`
+	Receivers []string `json:"receivers"`
+	Subject   string   `json:"subject"`
+	Content   string   `json:"content"`
+}
+
+func NewEmail(sender string, receivers []string, subject, content string) Email {
+	return Email{
+		Sender:    sender,
+		Receivers: receivers,
+		Subject:   subject,
+		Content:   content,
+	}
+}
+
+func FromJSON(path string) error {
+	content, err := ioutil.ReadFile(path)
+	if err != nil {
+		return err
+	}
+
+	var mail Email
+	if err := json.Unmarshal(content, &mail); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (e Email) Generate() []byte {
+	mail := fmt.Sprintf(
+		"To: %s\nFrom: %s\nContent-Type: text/html\nSubject: %s\n\n%s",
+		strings.Join(e.Receivers, ","),
+		e.Sender,
+		e.Sender,
+		e.Content,
+	)
+	return []byte(mail)
+}

main.go

@@ -3,79 +3,22 @@ package main
 import (
 	"errors"
 	"fmt"
-	"net/smtp"
 	"os"
-	"strings"
+
+	cfg "mailsrv/config"
+	"mailsrv/mail"
+	srv "mailsrv/services"
 
 	"github.com/go-kit/kit/log"
 	"github.com/go-kit/kit/log/level"
-	"gopkg.in/ini.v1"
+	ini "gopkg.in/ini.v1"
 )
 
-// mandatory parameters to send an email
+const (
-type SMTPConfig struct {
+	DefaultOutboxPath string = "outbox"
-	User     string
-	Password string
-	Url      string
-	Port     string
-}
-
-func NewSMTPConfig(user, password, url, port string) (SMTPConfig, error) {
-	var config SMTPConfig
-	if user == "" {
-		return config, errors.New("SMTP user can't be empty")
-	}
-	config.User = user
-
-	if password == "" {
-		return config, errors.New("SMTP password can't be empty")
-	}
-	config.Password = password
-
-	if url == "" {
-		return config, errors.New("SMTP server url can't be empty")
-	}
-	config.Url = url
-
-	if port == "" {
-		return config, errors.New("SMTP server port can't be empty")
-	}
-	config.Port = port
-
-	return config, nil
-}
-
-func (c SMTPConfig) getFullUrl() string {
-	return fmt.Sprintf("%s:%s", c.Url, c.Port)
-}
-
-type Email struct {
-	Sender    string
-	Receivers []string
-	Subject   string
-	Content   string
-}
-
-func NewEmail(sender string, receivers []string, subject, content string) Email {
-	return Email{
-		Sender:    sender,
-		Receivers: receivers,
-		Subject:   subject,
-		Content:   content,
-	}
-}
-
-func (e Email) Generate() []byte {
-	mail := fmt.Sprintf(
-		"To: %s\nFrom: %s\nContent-Type: text/html\nSubject: %s\n\n%s",
-		strings.Join(e.Receivers, ","),
-		e.Sender,
-		e.Sender,
-		e.Content,
 )
-	return []byte(mail)
-}
 
+// simply collects binary arguments
 func GetConfigPath() (string, error) {
 	switch len(os.Args) {
 	case 1:
@@ -87,21 +30,26 @@ func GetConfigPath() (string, error) {
 	}
 }
 
-func LoadConfig(configPath string) (SMTPConfig, error) {
+func LoadIni() (*ini.File, error) {
-	var config SMTPConfig
-
 	configPath, err := GetConfigPath()
 	if err != nil {
-		return config, fmt.Errorf("unable to get the .ini config path err=%v", err)
+		return nil, fmt.Errorf("unable to get the .ini config path err=%v", err)
 	}
 
-	cfg, err := ini.Load(configPath)
+	ini, err := ini.Load(configPath)
 	if err != nil {
-		return config, fmt.Errorf("unable to load the .ini config path err=%v", err)
+		return nil, fmt.Errorf("unable to load the .ini config path err=%v", err)
 	}
 
-	section := cfg.Section("server")
+	return ini, nil
-	config, err = NewSMTPConfig(
+}
+
+// collects mandatory SMTP parameters to send an e-mail from the `.ini` file
+func LoadSMTPConfig(iniFile *ini.File) (cfg.SMTPConfig, error) {
+	var config cfg.SMTPConfig
+
+	section := iniFile.Section("server")
+	config, err := cfg.NewSMTPConfig(
 		section.Key("username").String(),
 		section.Key("password").String(),
 		section.Key("url").String(),
@@ -114,37 +62,48 @@ func LoadConfig(configPath string) (SMTPConfig, error) {
 	return config, nil
 }
 
+// tries to get the outbox path from the `.ini` file and creates the directory
+// if the path does not exist, create a default one: `outbox` next to the binary
+func GetOutboxPath(iniFile *ini.File) (string, error) {
+	outboxPath := iniFile.Section("service").Key("outbox_path").String()
+	if outboxPath == "" {
+		outboxPath = DefaultOutboxPath
+	}
+
+	if err := os.MkdirAll(outboxPath, 0750); err != nil && !os.IsExist(err) {
+		return "", err
+	}
+
+	return outboxPath, nil
+}
+
 func main() {
 	var logger log.Logger
 	logger = log.NewLogfmtLogger(log.NewSyncWriter(os.Stderr))
 	logger = log.With(logger, "ts", log.DefaultTimestampUTC, "caller", log.DefaultCaller, "service", "mailsrv")
 
-	configPath, err := GetConfigPath()
+	iniFile, err := LoadIni()
 	if err != nil {
-		level.Error(logger).Log("msg", "unable to get the .ini config path", "err", err)
+		level.Error(logger).Log("msg", "unable to load the .ini configuration file", "err", err)
-		os.Exit(1)
+		return
 	}
 
-	config, err := LoadConfig(configPath)
+	config, err := LoadSMTPConfig(iniFile)
 	if err != nil {
 		level.Error(logger).Log("msg", "unable to load the SMTP configuration", "err", err)
-		os.Exit(1)
+		return
+	}
+
+	outboxPath, err := GetOutboxPath(iniFile)
+	if err != nil {
+		level.Error(logger).Log("msg", "unable to retrieve outputbox path", "err", err)
+		return
 	}
 
 	logger.Log("action", "send email test")
-
 	content := fmt.Sprintf("Hi!<br/><br/>This is an e-mail test, please do not reply.<br/><br/>Thegux Administrator<br/>%s", `<hr/>visit the website: <a href="https://thegux.fr">thegux.fr</a>`)
-	email := NewEmail(config.User, []string{"receiver@receiver.com"}, "e-mail test", content)
+	email := mail.NewEmail(config.User, []string{"example@example.com"}, "e-mail test", content)
 
-	auth := smtp.PlainAuth("", config.User, config.Password, config.Url)
+	sender := srv.NewSender(logger, config, outboxPath)
-	logger.Log("action", "authentication succeed")
+	sender.SendMail(email)
-
-	fmt.Println(config.getFullUrl())
-
-	if err := smtp.SendMail(config.getFullUrl(), auth, email.Sender, email.Receivers, email.Generate()); err != nil {
-		level.Error(logger).Log("msg", "error while sending email", "err", err)
-		os.Exit(1)
-	}
-
-	logger.Log("msg", "mail send successfully")
 }

services/sender.go

@@ -0,0 +1,39 @@
+package services
+
+import (
+	cfg "mailsrv/config"
+	"mailsrv/mail"
+
+	"github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/log/level"
+	"net/smtp"
+)
+
+type Sender struct {
+	SMTPConfig cfg.SMTPConfig
+	logger     log.Logger
+	// fetch this directory to collect `.json` e-mail format
+	OutboxPath string
+}
+
+func NewSender(logger log.Logger, config cfg.SMTPConfig, outboxPath string) Sender {
+	logger = log.With(logger, "actor", "sender")
+	return Sender{
+		SMTPConfig: config,
+		logger:     logger,
+		OutboxPath: outboxPath,
+	}
+}
+
+func (s Sender) SendMail(email mail.Email) error {
+	auth := smtp.PlainAuth("", s.SMTPConfig.User, s.SMTPConfig.Password, s.SMTPConfig.Url)
+	s.logger.Log("action", "authentication succeed")
+
+	if err := smtp.SendMail(s.SMTPConfig.GetFullUrl(), auth, email.Sender, email.Receivers, email.Generate()); err != nil {
+		level.Error(s.logger).Log("msg", "error while sending email", "err", err)
+		return err
+	}
+
+	s.logger.Log("msg", "mail send successfully")
+	return nil
+}