Wrap email errs (#884)

* wrap errors returned by SMTP client

* remove client hello

server/mail/mail.go

@@ -7,6 +7,7 @@ import (
 	"net/smtp"
 
 	"github.com/kolide/kolide-ose/server/kolide"
+	"github.com/pkg/errors"
 )
 
 func NewService() kolide.MailService {
@@ -27,11 +28,17 @@ type sender interface {
 func Test(mailer kolide.MailService, e kolide.Email) error {
 	mailBody, err := getMessageBody(e)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to get message body")
 	}
 
-	if svc, ok := mailer.(sender); ok {
-		return svc.sendMail(e, mailBody)
+	svc, ok := mailer.(sender)
+	if !ok {
+		return nil
+	}
+
+	err = svc.sendMail(e, mailBody)
+	if err != nil {
+		return errors.Wrap(err, "sending mail")
 	}
 
 	return nil
@@ -45,7 +52,7 @@ const (
 func getMessageBody(e kolide.Email) ([]byte, error) {
 	body, err := e.Mailer.Message()
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "get mailer message")
 	}
 	mime := `MIME-version: 1.0;` + "\r\n"
 	content := `Content-Type: text/html; charset="UTF-8";` + "\r\n"
@@ -74,31 +81,42 @@ func (m mailService) SendEmail(e kolide.Email) error {
 	return m.sendMail(e, msg)
 }
 
+func smtpAuth(e kolide.Email) (smtp.Auth, error) {
+	if e.Config.SMTPAuthenticationType != kolide.AuthTypeUserNamePassword {
+		return nil, nil
+	}
+	var auth smtp.Auth
+	switch e.Config.SMTPAuthenticationMethod {
+	case kolide.AuthMethodCramMD5:
+		auth = smtp.CRAMMD5Auth(e.Config.SMTPUserName, e.Config.SMTPPassword)
+	case kolide.AuthMethodPlain:
+		auth = smtp.PlainAuth("", e.Config.SMTPUserName, e.Config.SMTPPassword, e.Config.SMTPServer)
+	default:
+		return nil, fmt.Errorf("unknown SMTP auth type '%d'", e.Config.SMTPAuthenticationMethod)
+	}
+	return auth, nil
+}
+
 func (m mailService) sendMail(e kolide.Email, msg []byte) error {
 	smtpHost := fmt.Sprintf("%s:%d", e.Config.SMTPServer, e.Config.SMTPPort)
-	var auth smtp.Auth
-	if e.Config.SMTPAuthenticationType == kolide.AuthTypeUserNamePassword {
-		switch e.Config.SMTPAuthenticationMethod {
-		case kolide.AuthMethodCramMD5:
-			auth = smtp.CRAMMD5Auth(e.Config.SMTPUserName, e.Config.SMTPPassword)
-			return smtp.SendMail(smtpHost, auth, e.Config.SMTPSenderAddress, e.To, msg)
-		case kolide.AuthMethodPlain:
-			auth = smtp.PlainAuth("", e.Config.SMTPUserName, e.Config.SMTPPassword, e.Config.SMTPServer)
-
-		default:
-			return fmt.Errorf("Unknown SMTP auth type '%d'", e.Config.SMTPAuthenticationMethod)
-		}
-	} else {
-		auth = nil
+	auth, err := smtpAuth(e)
+	if err != nil {
+		return errors.Wrap(err, "failed to get smtp auth")
 	}
+
+	if e.Config.SMTPAuthenticationMethod == kolide.AuthMethodCramMD5 {
+		err = smtp.SendMail(smtpHost, auth, e.Config.SMTPSenderAddress, e.To, msg)
+		if err != nil {
+			return errors.Wrap(err, "failed to send mail. cramd5 auth method")
+		}
+		return nil
+	}
+
 	client, err := smtp.Dial(smtpHost)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "could not dial smtp host")
 	}
 	defer client.Close()
-	if err = client.Hello(""); err != nil {
-		return err
-	}
 	if e.Config.SMTPEnableStartTLS {
 		if ok, _ := client.Extension("STARTTLS"); ok {
 			config := &tls.Config{
@@ -106,30 +124,34 @@ func (m mailService) sendMail(e kolide.Email, msg []byte) error {
 				InsecureSkipVerify: !e.Config.SMTPVerifySSLCerts,
 			}
 			if err = client.StartTLS(config); err != nil {
-				return err
+				return errors.Wrap(err, "startTLS error")
 			}
 		}
 	}
 	if auth != nil {
 		if err = client.Auth(auth); err != nil {
-			return err
+			return errors.Wrap(err, "client auth error")
 		}
 	}
 	if err = client.Mail(e.Config.SMTPSenderAddress); err != nil {
-		return err
+		return errors.Wrap(err, "could not issue mail to provided address")
 	}
 	for _, recip := range e.To {
 		if err = client.Rcpt(recip); err != nil {
-			return err
+			return errors.Wrap(err, "failed to get recipient")
 		}
 	}
 	writer, err := client.Data()
 	if err != nil {
-		return nil
+		return errors.Wrap(err, "getting client data")
 	}
 	_, err = writer.Write(msg)
 	if err = writer.Close(); err != nil {
-		return err
+		return errors.Wrap(err, "failed to close writer")
 	}
-	return client.Quit()
+
+	if err := client.Quit(); err != nil {
+		return errors.Wrap(err, "error on client quit")
+	}
+	return nil
 }