cherrypick notification changes from #450 (#745)

pkg/notifications/email.go

@@ -1,29 +1,22 @@
 package notifications
 
 import (
-	"encoding/base64"
-	"fmt"
-	"github.com/spf13/cobra"
-	"net/smtp"
 	"os"
-	"strings"
 	"time"
 
+	"github.com/spf13/cobra"
+
+	shoutrrrSmtp "github.com/containrrr/shoutrrr/pkg/services/smtp"
 	t "github.com/containrrr/watchtower/pkg/types"
 	log "github.com/sirupsen/logrus"
-	"strconv"
 )
 
 const (
 	emailType = "email"
 )
 
-// Implements Notifier, logrus.Hook
-// The default logrus email integration would have several issues:
-// - It would send one email per log output
-// - It would only send errors
-// We work around that by holding on to log entries until the update cycle is done.
 type emailTypeNotifier struct {
+	url                                string
 	From, To                           string
 	Server, User, Password, SubjectTag string
 	Port                               int
@@ -33,7 +26,12 @@ type emailTypeNotifier struct {
 	delay                              time.Duration
 }
 
-func newEmailNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
+// NewEmailNotifier is a factory method creating a new email notifier instance
+func NewEmailNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.ConvertableNotifier {
+	return newEmailNotifier(c, acceptedLogLevels)
+}
+
+func newEmailNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.ConvertableNotifier {
 	flags := c.PersistentFlags()
 
 	from, _ := flags.GetString("notification-email-from")
@@ -47,6 +45,7 @@ func newEmailNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.Notifie
 	subjecttag, _ := flags.GetString("notification-email-subjecttag")
 
 	n := &emailTypeNotifier{
+		entries:       []*log.Entry{},
 		From:          from,
 		To:            to,
 		Server:        server,
@@ -59,12 +58,33 @@ func newEmailNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.Notifie
 		SubjectTag:    subjecttag,
 	}
 
-	log.AddHook(n)
-
 	return n
 }
 
-func (e *emailTypeNotifier) buildMessage(entries []*log.Entry) []byte {
+func (e *emailTypeNotifier) GetURL() string {
+	conf := &shoutrrrSmtp.Config{
+		FromAddress: e.From,
+		FromName:    "Watchtower",
+		ToAddresses: []string{e.To},
+		Port:        uint16(e.Port),
+		Host:        e.Server,
+		Subject:     e.getSubject(),
+		Username:    e.User,
+		Password:    e.Password,
+		UseStartTLS: true,
+		UseHTML:     false,
+	}
+
+	if len(e.User) > 0 {
+		conf.Set("auth", "Plain")
+	} else {
+		conf.Set("auth", "None")
+	}
+
+	return conf.GetURL().String()
+}
+
+func (e *emailTypeNotifier) getSubject() string {
 	var emailSubject string
 
 	if e.SubjectTag == "" {
@@ -75,83 +95,13 @@ func (e *emailTypeNotifier) buildMessage(entries []*log.Entry) []byte {
 	if hostname, err := os.Hostname(); err == nil {
 		emailSubject += " on " + hostname
 	}
-	body := ""
-	for _, entry := range entries {
-		body += entry.Time.Format("2006-01-02 15:04:05") + " (" + entry.Level.String() + "): " + entry.Message + "\r\n"
-		// We don't use fields in watchtower, so don't bother sending them.
-	}
-
-	t := time.Now()
-
-	header := make(map[string]string)
-	header["From"] = e.From
-	header["To"] = e.To
-	header["Subject"] = emailSubject
-	header["Date"] = t.Format(time.RFC1123Z)
-	header["MIME-Version"] = "1.0"
-	header["Content-Type"] = "text/plain; charset=\"utf-8\""
-	header["Content-Transfer-Encoding"] = "base64"
-
-	message := ""
-	for k, v := range header {
-		message += fmt.Sprintf("%s: %s\r\n", k, v)
-	}
-
-	encodedBody := base64.StdEncoding.EncodeToString([]byte(body))
-	//RFC 2045 base64 encoding demands line no longer than 76 characters.
-	for _, line := range SplitSubN(encodedBody, 76) {
-		message += "\r\n" + line
-	}
-
-	return []byte(message)
+	return emailSubject
 }
 
-func (e *emailTypeNotifier) sendEntries(entries []*log.Entry) {
-	// Do the sending in a separate goroutine so we don't block the main process.
-	msg := e.buildMessage(entries)
-	go func() {
-		if e.delay > 0 {
-			time.Sleep(e.delay)
-		}
-
-		var auth smtp.Auth
-		if e.User != "" {
-			auth = smtp.PlainAuth("", e.User, e.Password, e.Server)
-		}
-		err := SendMail(e.Server+":"+strconv.Itoa(e.Port), e.tlsSkipVerify, auth, e.From, strings.Split(e.To, ","), msg)
-		if err != nil {
-			// Use fmt so it doesn't trigger another email.
-			fmt.Println("Failed to send notification email: ", err)
-		}
-	}()
-}
-
-func (e *emailTypeNotifier) StartNotification() {
-	if e.entries == nil {
-		e.entries = make([]*log.Entry, 0, 10)
-	}
-}
-
-func (e *emailTypeNotifier) SendNotification() {
-	if e.entries == nil || len(e.entries) <= 0 {
-		return
-	}
-
-	e.sendEntries(e.entries)
-	e.entries = nil
-}
-
-func (e *emailTypeNotifier) Levels() []log.Level {
-	return e.logLevels
-}
-
-func (e *emailTypeNotifier) Fire(entry *log.Entry) error {
-	if e.entries != nil {
-		e.entries = append(e.entries, entry)
-	} else {
-		e.sendEntries([]*log.Entry{entry})
-	}
-	return nil
-}
+// TODO: Delete these once all notifiers have been converted to shoutrrr
+func (e *emailTypeNotifier) StartNotification()          {}
+func (e *emailTypeNotifier) SendNotification()           {}
+func (e *emailTypeNotifier) Levels() []log.Level         { return nil }
+func (e *emailTypeNotifier) Fire(entry *log.Entry) error { return nil }
 
 func (e *emailTypeNotifier) Close() {}