statusmon/core/notifier_slack.go

package core

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"

	"github.com/spf13/viper"
)

var notificationColors = map[string]string{
	CheckOk:  "#00ff00",
	CheckErr: "#ff0000",
}

type SlackNotifier struct {
	NotifierOpts
}

type SlackMessage struct {
	Text        string            `json:"text"`
	Username    string            `json:"username,omitempty`
	Attachments []SlackAttachment `json:"attachments,omitempty"`
}

type SlackAttachment struct {
	Text  string `json:"text"`
	Color string `json:"color,omitempty"`
}

func (n SlackNotifier) New(config TransportConfig) (AbstractNotifier, error) {
	if config.Options.Recipients == nil {
		// fall back to global webhooks config :TransportConfSourceHack
		webhooks := viper.GetStringSlice("slack.webhooks")
		if len(webhooks) > 0 {
			return SlackNotifier{NotifierOpts: NotifierOpts{Recipients: webhooks}}, nil
		}
		return nil, fmt.Errorf("Missing entries in config slack.webhooks")
	}
	return SlackNotifier{NotifierOpts: config.Options}, nil
}

func (n SlackNotifier) Submit(notification Notification) error {
	msg, err := json.Marshal(SlackMessage{
		Username:    "statusmon",
		Text:        notification.Subject,
		Attachments: []SlackAttachment{{notification.Body, notificationColors[notification.Status]}},
	})
	if err != nil {
		return err
	}
	msgBuf := bytes.NewBuffer(msg)

	for _, url := range n.Recipients {
		res, err := http.Post(url, "application/json", msgBuf)
		if err != nil {
			return err
		}

		if res.StatusCode > 204 {
			defer res.Body.Close()
			body, _ := ioutil.ReadAll(res.Body)
			return fmt.Errorf("slack webhook failed: %s", body)
		}
	}

	return nil
}