Add new dispatcher Slack (dsrvlabs#538)

cmd/init.go

@@ -34,6 +34,8 @@ func createInitCommand(initializer tp.Initializer) *cobra.Command {
         secret: "Put your Discord Webhook"
       - channel: "pagerduty"
         secret: "Put your PagerDuty's Integration Key (Events API v2)"
+      - channel: "slack"
+        secret: "Put Your Slack Webhook url"
       - channel: "telegram"
         secret: "Put Your Bot's Token"
         chat_id: "Put Your Chat's chat_id"

manager/dispatcher/dispatcher.go

@@ -71,6 +71,15 @@ func GetDispatchers(cfg config.NotificationInfo) []Dispatcher {
 					reminderSchedule: chanInfo.ReminderSchedule,
 					entry:            sync.Map{},
 				})
+			case strings.EqualFold(channel, string(tp.Slack)):
+				dispatcherSingletons = append(dispatcherSingletons, &slack{
+					host:             cfg.HostName,
+					channel:          tp.Slack,
+					secret:           chanInfo.Secret,
+					reminderCron:     cron.New(cron.WithLocation(time.UTC)),
+					reminderSchedule: chanInfo.ReminderSchedule,
+					entry:            sync.Map{},
+				})
 			case strings.EqualFold(channel, string(tp.PagerDuty)):
 				dispatcherSingletons = append(dispatcherSingletons, &pagerduty{
 					host:       cfg.HostName,

manager/dispatcher/slack.go

@@ -0,0 +1,126 @@
+package dispatcher
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"sync"
+
+	pb "github.com/dsrvlabs/vatz-proto/plugin/v1"
+	tp "github.com/dsrvlabs/vatz/manager/types"
+	"github.com/robfig/cron/v3"
+	"github.com/rs/zerolog/log"
+)
+
+// slack: This is a sample code
+// that helps to multi methods for notification.
+type slack struct {
+	host             string
+	channel          tp.Channel
+	secret           string
+	reminderSchedule []string
+	reminderCron     *cron.Cron
+	entry            sync.Map
+}
+
+type SlackRequestBody struct {
+	Text string `json:"text"`
+}
+
+func (t *slack) SetDispatcher(firstRunMsg bool, preStat tp.StateFlag, notifyInfo tp.NotifyInfo) error {
+	reqToNotify, reminderState, deliverMessage := messageHandler(firstRunMsg, preStat, notifyInfo)
+	pUnique := deliverMessage.Options["pUnique"].(string)
+
+	if reqToNotify {
+		err := t.SendNotification(deliverMessage)
+		if err != nil {
+			log.Error().Str("module", "dispatcher").Msgf("Channel(Slack): Send notification error: %s", err)
+			return err
+		}
+
+	}
+
+	if reminderState == tp.ON {
+		newEntries := []cron.EntryID{}
+		/*
+			In case of reminder has to keep but stateFlag has changed,
+			e.g.) CRITICAL -> WARNING
+			e.g.) ERROR -> INFO -> ERROR
+		*/
+		if entries, ok := t.entry.Load(pUnique); ok {
+			for _, entry := range entries.([]cron.EntryID) {
+				t.reminderCron.Remove(entry)
+			}
+			t.reminderCron.Stop()
+		}
+		for _, schedule := range t.reminderSchedule {
+			id, _ := t.reminderCron.AddFunc(schedule, func() {
+				err := t.SendNotification(deliverMessage)
+				if err != nil {
+					log.Error().Str("module", "dispatcher").Msgf("Channel(Slack): Send notification error: %s", err)
+				}
+			})
+			newEntries = append(newEntries, id)
+		}
+		t.entry.Store(pUnique, newEntries)
+		t.reminderCron.Start()
+	} else if reminderState == tp.OFF {
+		entries, _ := t.entry.Load(pUnique)
+		if _, ok := entries.([]cron.EntryID); ok {
+			for _, entity := range entries.([]cron.EntryID) {
+				t.reminderCron.Remove(entity)
+			}
+			t.reminderCron.Stop()
+		}
+	}
+	return nil
+}
+
+func (t *slack) SendNotification(msg tp.ReqMsg) error {
+	var (
+		err   error
+		emoji = emojiER
+	)
+
+	if msg.State == pb.STATE_SUCCESS {
+		switch {
+		case msg.Severity == pb.SEVERITY_CRITICAL:
+			emoji = emojiDoubleEX
+		case msg.Severity == pb.SEVERITY_WARNING:
+			emoji = emojiSingleEx
+		case msg.Severity == pb.SEVERITY_INFO:
+			emoji = emojiCheck
+		}
+	}
+	sendingText := fmt.Sprintf(`
+%s *%s* %s
+> 
+Host: *%s*
+Plugin Name: _%s_
+%s`, emoji, msg.Severity.String(), emoji, t.host, msg.ResourceType, msg.Msg)
+	slackBody, _ := json.Marshal(SlackRequestBody{Text: sendingText})
+	req, err := http.NewRequest(http.MethodPost, t.secret, bytes.NewBuffer(slackBody))
+	if err != nil {
+		return err
+	}
+
+	req.Header.Add("Content-Type", "application/json")
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+
+	buf := new(bytes.Buffer)
+	_, err = buf.ReadFrom(resp.Body)
+	if err != nil {
+		return err
+	}
+	if buf.String() != "ok" {
+		return fmt.Errorf("non-ok response returned from Slack")
+	}
+
+	return nil
+}

manager/dispatcher/telegram.go

@@ -96,7 +96,7 @@ func (t *telegram) SendNotification(msg tp.ReqMsg) error {
 	url := fmt.Sprintf("%s/sendMessage", getURL(t.secret))
 	sendingText := fmt.Sprintf(`
 %s<strong>%s</strong>%s
-<strong>(%s)</strong>
+Host: <strong>%s</strong>
 Plugin Name: <em>%s</em>
 %s`, emoji, msg.Severity.String(), emoji, t.host, msg.ResourceType, msg.Msg)
 

manager/types/dispatcher.go

@@ -111,6 +111,7 @@ const (
 	Discord   Channel = "DISCORD"
 	Telegram  Channel = "TELEGRAM"
 	PagerDuty Channel = "PAGERDUTY"
+	Slack     Channel = "SLACK"
 )
 
 // Reminder is for reminnig alert.