email: Add smtp emailer

email/interface.go

@@ -3,6 +3,7 @@ package email
 import (
 	"encoding/json"
 	"errors"
+	"expvar"
 	"fmt"
 	"io"
 	"os"
@@ -14,7 +15,8 @@ const (
 )
 
 var (
-	ErrorNoTemplate = errors.New("No HTML or Text template found for template name.")
+	counterEmailSendErr = expvar.NewInt("email.send.err")
+	ErrorNoTemplate     = errors.New("No HTML or Text template found for template name.")
 )
 
 func init() {

email/mailgun.go

@@ -3,7 +3,6 @@ package email
 import (
 	"encoding/json"
 	"errors"
-	"expvar"
 
 	"github.com/coreos/dex/pkg/log"
 	mailgun "github.com/mailgun/mailgun-go"
@@ -13,10 +12,6 @@ const (
 	MailgunEmailerType = "mailgun"
 )
 
-var (
-	counterEmailSendErr = expvar.NewInt("mailgun.send.err")
-)
-
 func init() {
 	RegisterEmailerConfigType(MailgunEmailerType, func() EmailerConfig { return &MailgunEmailerConfig{} })
 }

email/smtp.go

@@ -0,0 +1,85 @@
+package email
+
+import (
+	"encoding/json"
+	"errors"
+
+	"gopkg.in/gomail.v2"
+)
+
+const (
+	SmtpEmailerType = "smtp"
+)
+
+func init() {
+	RegisterEmailerConfigType(SmtpEmailerType, func() EmailerConfig { return &SmtpEmailerConfig{} })
+}
+
+type SmtpEmailerConfig struct {
+	ID       string `json:"id"`
+	Host     string `json:"host"`
+	Port     int    `json:"port"`
+	Auth     string `json:"auth"`
+	Username string `json:"username"`
+	Password string `json:"password"`
+}
+
+func (cfg SmtpEmailerConfig) EmailerType() string {
+	return SmtpEmailerType
+}
+
+func (cfg SmtpEmailerConfig) EmailerID() string {
+	return cfg.ID
+}
+
+func (cfg SmtpEmailerConfig) Emailer() (Emailer, error) {
+	var dialer *gomail.Dialer
+	if cfg.Auth == "plain" {
+		dialer = gomail.NewPlainDialer(cfg.Host, cfg.Port, cfg.Username, cfg.Password)
+	} else {
+		dialer = &gomail.Dialer{
+			Host: cfg.Host,
+			Port: cfg.Port,
+		}
+	}
+	return &smtpEmailer{
+		dialer: dialer,
+	}, nil
+}
+
+type smtpEmailerConfig SmtpEmailerConfig
+
+func (cfg *SmtpEmailerConfig) UnmarshalJSON(data []byte) error {
+	smtpCfg := smtpEmailerConfig{}
+	err := json.Unmarshal(data, &smtpCfg)
+	if err != nil {
+		return err
+	}
+	if smtpCfg.Host == "" {
+		return errors.New("must set SMTP host")
+	}
+	if smtpCfg.Port == "" {
+		return errors.New("must set SMTP port")
+	}
+	*cfg = SmtpEmailerConfig(smtpCfg)
+	return nil
+}
+
+type smtpEmailer struct {
+	dialer *gomail.Dialer
+}
+
+func (emailer *smtpEmailer) SendMail(from, subject, text, html string, to ...string) error {
+	msg := gomail.NewMessage()
+	msg.SetHeader("From", from)
+	msg.SetHeader("To", to...)
+	msg.SetHeader("Subject", subject)
+	msg.SetBody("text/plain", text)
+	msg.SetBody("text/html", html)
+	err := emailer.dialer.DialAndSend(msg)
+	if err != nil {
+		counterEmailSendErr.Add(1)
+		return err
+	}
+	return nil
+}