add slack output

Gopkg.toml

@@ -1,6 +1,14 @@
 [prune]
   go-tests = true
 
+[[constraint]]
+  name = "github.com/spf13/cobra"
+  version = "0.0.3"
+
+[[constraint]]
+  name = "github.com/sensu/sensu-go"
+  version = "5.7.0"
+
 [[constraint]]
   name = "github.com/go-redis/redis"
   version = "6.15.2"
@@ -10,9 +18,5 @@
   name = "github.com/mattn/go-redmine"
 
 [[constraint]]
-  name = "github.com/sensu/sensu-go"
-  version = "5.7.0"
-
-[[constraint]]
-  name = "github.com/spf13/cobra"
-  version = "0.0.3"
+  branch = "master"
+  name = "github.com/bluele/slack"

cmd/event.go

@@ -63,6 +63,21 @@ func init() {
 		"mail-from",
 		os.Getenv("MAIL_FROM"),
 		"The sender address for emails, defaults to value of MAIL_FROM env variable")
+
+	eventCmd.PersistentFlags().StringVar(&handlerConfig.SlackWebhookURL,
+		"slack-webhook-url",
+		os.Getenv("SLACK_WEBHOOK_URL"),
+		"The webhook url to send messages to, defaults to value of SLACK_WEBHOOK_URL env variable")
+
+	eventCmd.PersistentFlags().StringVar(&handlerConfig.SlackUsername,
+		"slack-username",
+		"sensu",
+		"The username that messages will be sent as")
+
+	eventCmd.PersistentFlags().StringVar(&handlerConfig.SlackIconURL,
+		"slack-icon-url",
+		"http://s3-us-west-2.amazonaws.com/sensuapp.org/sensu.png",
+		"A URL to an image to use as the user avatar")
 }
 
 func loadEvent() (*types.Event, error) {

handler/helpers.go

@@ -4,6 +4,8 @@ package handler
 
 import (
 	"bytes"
+	"fmt"
+	"strings"
 	"text/template"
 
 	sensu "github.com/sensu/sensu-go/types"
@@ -24,3 +26,45 @@ func resolveTemplate(templateValue string, event *sensu.Event) (string, error) {
 
 	return resolved.String(), nil
 }
+
+func chomp(s string) string {
+	return strings.Trim(strings.Trim(strings.Trim(s, "\n"), "\r"), "\r\n")
+}
+
+func messageStatus(event *sensu.Event) string {
+	switch event.Check.Status {
+	case 0:
+		return "Resolved"
+	case 2:
+		return "Critical"
+	default:
+		return "Warning"
+	}
+}
+
+func formattedEventAction(event *sensu.Event) string {
+	switch event.Check.Status {
+	case 0:
+		return "RESOLVED"
+	default:
+		return "ALERT"
+	}
+}
+
+func eventKey(event *sensu.Event) string {
+	return fmt.Sprintf("%s/%s", event.Entity.Name, event.Check.Name)
+}
+
+func eventSummary(event *sensu.Event, maxLength int) string {
+	output := chomp(event.Check.Output)
+
+	if len(event.Check.Output) > maxLength {
+		output = output[0:maxLength] + "..."
+	}
+
+	return fmt.Sprintf("%s:%s", eventKey(event), output)
+}
+
+func formattedMessage(event *sensu.Event) string {
+	return fmt.Sprintf("%s - %s", formattedEventAction(event), eventSummary(event, 100))
+}

handler/mail.go

@@ -1,4 +1,5 @@
 // Copyright © 2019 SIC! Software GmbH
+// Adapted from https://github.com/sensu/sensu-email-handler
 
 package handler
 

handler/slack.go

@@ -1,14 +1,60 @@
 // Copyright © 2019 SIC! Software GmbH
+// Adapted from https://github.com/sensu/sensu-slack-handler
 
 package handler
 
 import (
+	"github.com/bluele/slack"
 	sensu "github.com/sensu/sensu-go/types"
 
 	"sensu-sic-handler/recipient"
 )
 
 // HandleSlack handles slack recipients (recipient.HandlerTypeSlack)
 func HandleSlack(recipient *recipient.Recipient, event *sensu.Event, config *Config) error {
-	return nil
+	hook := slack.NewWebHook(config.SlackWebhookURL)
+
+	return hook.PostMessage(&slack.WebHookPostPayload{
+		Attachments: []*slack.Attachment{slackMessageAttachment(event)},
+		Channel:     recipient.Args["channel"],
+		IconUrl:     config.SlackIconURL,
+		Username:    config.SlackUsername,
+	})
+}
+
+func slackMessageColor(event *sensu.Event) string {
+	switch event.Check.Status {
+	case 0:
+		return "good"
+	case 2:
+		return "danger"
+	default:
+		return "warning"
+	}
+}
+
+func slackMessageAttachment(event *sensu.Event) *slack.Attachment {
+	return &slack.Attachment{
+		Title:    "Description",
+		Text:     event.Check.Output,
+		Fallback: formattedMessage(event),
+		Color:    slackMessageColor(event),
+		Fields: []*slack.AttachmentField{
+			&slack.AttachmentField{
+				Title: "Status",
+				Value: messageStatus(event),
+				Short: false,
+			},
+			&slack.AttachmentField{
+				Title: "Entity",
+				Value: event.Entity.Name,
+				Short: true,
+			},
+			&slack.AttachmentField{
+				Title: "Check",
+				Value: event.Check.Name,
+				Short: true,
+			},
+		},
+	}
 }

handler/types.go

@@ -4,6 +4,9 @@ package handler
 
 // Config configuration for handlers
 type Config struct {
-	SMTPAddress string
-	MailFrom    string
+	SMTPAddress     string
+	MailFrom        string
+	SlackWebhookURL string
+	SlackUsername   string
+	SlackIconURL    string
 }