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watchtower/pkg/notifications/shoutrrr.go

239 lines
6.2 KiB
Go

package notifications
import (
"bytes"
stdlog "log"
"os"
"strings"
"text/template"
"time"
"github.com/containrrr/shoutrrr"
"github.com/containrrr/shoutrrr/pkg/types"
"github.com/containrrr/watchtower/pkg/notifications/templates"
t "github.com/containrrr/watchtower/pkg/types"
log "github.com/sirupsen/logrus"
)
// LocalLog is a logrus logger that does not send entries as notifications
var LocalLog = log.WithField("notify", "no")
const (
shoutrrrType = "shoutrrr"
)
type router interface {
Send(message string, params *types.Params) []error
}
// Implements Notifier, logrus.Hook
type shoutrrrTypeNotifier struct {
Urls []string
Router router
entries []*log.Entry
logLevel log.Level
template *template.Template
messages chan string
done chan bool
legacyTemplate bool
params *types.Params
data StaticData
receiving bool
delay time.Duration
}
// GetScheme returns the scheme part of a Shoutrrr URL
func GetScheme(url string) string {
schemeEnd := strings.Index(url, ":")
if schemeEnd <= 0 {
return "invalid"
}
return url[:schemeEnd]
}
// GetNames returns a list of notification services that has been added
func (n *shoutrrrTypeNotifier) GetNames() []string {
names := make([]string, len(n.Urls))
for i, u := range n.Urls {
names[i] = GetScheme(u)
}
return names
}
// GetURLs returns a list of URLs for notification services that has been added
func (n *shoutrrrTypeNotifier) GetURLs() []string {
return n.Urls
}
// AddLogHook adds the notifier as a receiver of log messages and starts a go func for processing them
func (n *shoutrrrTypeNotifier) AddLogHook() {
if n.receiving {
return
}
n.receiving = true
log.AddHook(n)
// Do the sending in a separate goroutine, so we don't block the main process.
go sendNotifications(n)
}
func createNotifier(urls []string, level log.Level, tplString string, legacy bool, data StaticData, stdout bool, delay time.Duration) *shoutrrrTypeNotifier {
tpl, err := getShoutrrrTemplate(tplString, legacy)
if err != nil {
log.Errorf("Could not use configured notification template: %s. Using default template", err)
}
var logger types.StdLogger
if stdout {
logger = stdlog.New(os.Stdout, ``, 0)
} else {
logger = stdlog.New(log.StandardLogger().WriterLevel(log.TraceLevel), "Shoutrrr: ", 0)
}
r, err := shoutrrr.NewSender(logger, urls...)
if err != nil {
log.Fatalf("Failed to initialize Shoutrrr notifications: %s\n", err.Error())
}
params := &types.Params{}
if data.Title != "" {
params.SetTitle(data.Title)
}
return &shoutrrrTypeNotifier{
Urls: urls,
Router: r,
messages: make(chan string, 1),
done: make(chan bool),
logLevel: level,
template: tpl,
legacyTemplate: legacy,
data: data,
params: params,
delay: delay,
}
}
func sendNotifications(n *shoutrrrTypeNotifier) {
for msg := range n.messages {
time.Sleep(n.delay)
errs := n.Router.Send(msg, n.params)
for i, err := range errs {
if err != nil {
scheme := GetScheme(n.Urls[i])
// Use fmt so it doesn't trigger another notification.
LocalLog.WithFields(log.Fields{
"service": scheme,
"index": i,
}).WithError(err).Error("Failed to send shoutrrr notification")
}
}
}
n.done <- true
}
func (n *shoutrrrTypeNotifier) buildMessage(data Data) (string, error) {
var body bytes.Buffer
var templateData interface{} = data
if n.legacyTemplate {
templateData = data.Entries
}
if err := n.template.Execute(&body, templateData); err != nil {
return "", err
}
return body.String(), nil
}
func (n *shoutrrrTypeNotifier) sendEntries(entries []*log.Entry, report t.Report) {
msg, err := n.buildMessage(Data{n.data, entries, report})
if msg == "" {
// Log in go func in case we entered from Fire to avoid stalling
go func() {
if err != nil {
LocalLog.WithError(err).Fatal("Notification template error")
} else if len(n.Urls) > 1 {
LocalLog.Info("Skipping notification due to empty message")
}
}()
return
}
n.messages <- msg
}
// StartNotification begins queueing up messages to send them as a batch
func (n *shoutrrrTypeNotifier) StartNotification() {
if n.entries == nil {
n.entries = make([]*log.Entry, 0, 10)
}
}
// SendNotification sends the queued up messages as a notification
func (n *shoutrrrTypeNotifier) SendNotification(report t.Report) {
n.sendEntries(n.entries, report)
n.entries = nil
}
// Close prevents further messages from being queued and waits until all the currently queued up messages have been sent
func (n *shoutrrrTypeNotifier) Close() {
close(n.messages)
// Use fmt so it doesn't trigger another notification.
LocalLog.Info("Waiting for the notification goroutine to finish")
<-n.done
}
// Levels return what log levels trigger notifications
func (n *shoutrrrTypeNotifier) Levels() []log.Level {
return log.AllLevels[:n.logLevel+1]
}
// Fire is the hook that logrus calls on a new log message
func (n *shoutrrrTypeNotifier) Fire(entry *log.Entry) error {
if entry.Data["notify"] == "no" {
// Skip logging if explicitly tagged as non-notify
return nil
}
if n.entries != nil {
n.entries = append(n.entries, entry)
} else {
// Log output generated outside a cycle is sent immediately.
n.sendEntries([]*log.Entry{entry}, nil)
}
return nil
}
func getShoutrrrTemplate(tplString string, legacy bool) (tpl *template.Template, err error) {
tplBase := template.New("").Funcs(templates.Funcs)
if builtin, found := commonTemplates[tplString]; found {
log.WithField(`template`, tplString).Debug(`Using common template`)
tplString = builtin
}
// If we succeed in getting a non-empty template configuration
// try to parse the template string.
if tplString != "" {
tpl, err = tplBase.Parse(tplString)
}
// If we had an error (either from parsing the template string
// or from getting the template configuration) or a
// template wasn't configured (the empty template string)
// fallback to using the default template.
if err != nil || tplString == "" {
defaultKey := `default`
if legacy {
defaultKey = `default-legacy`
}
tpl = template.Must(tplBase.Parse(commonTemplates[defaultKey]))
}
return
}