You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
watchtower/pkg/notifications/email.go

158 lines
4.1 KiB
Go

package notifications
import (
"encoding/base64"
"fmt"
"github.com/spf13/cobra"
"github.com/spf13/viper"
"net/smtp"
"os"
"strings"
"time"
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 {
From, To string
Server, User, Password, SubjectTag string
Port int
tlsSkipVerify bool
entries []*log.Entry
logLevels []log.Level
delay time.Duration
}
func newEmailNotifier(_ *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
from := viper.GetString("notification-email-from")
to := viper.GetString("notification-email-to")
server := viper.GetString("notification-email-server")
user := viper.GetString("notification-email-server-user")
password := viper.GetString("notification-email-server-password")
port := viper.GetInt("notification-email-server-port")
tlsSkipVerify := viper.GetBool("notification-email-server-tls-skip-verify")
delay := viper.GetInt("notification-email-delay")
subjecttag := viper.GetString("notification-email-subjecttag")
n := &emailTypeNotifier{
From: from,
To: to,
Server: server,
User: user,
Password: password,
Port: port,
tlsSkipVerify: tlsSkipVerify,
logLevels: acceptedLogLevels,
delay: time.Duration(delay) * time.Second,
SubjectTag: subjecttag,
}
log.AddHook(n)
return n
}
func (e *emailTypeNotifier) buildMessage(entries []*log.Entry) []byte {
var emailSubject string
if e.SubjectTag == "" {
emailSubject = "Watchtower updates"
} else {
emailSubject = e.SubjectTag + " Watchtower updates"
}
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.
}
now := time.Now()
header := make(map[string]string)
header["From"] = e.From
header["To"] = e.To
header["Subject"] = emailSubject
header["Date"] = now.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)
}
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
}
func (e *emailTypeNotifier) Close() {}