Add discord notification service. Close #143

notifications/discord.go

@@ -0,0 +1,96 @@
+package notifications
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/urfave/cli"
+)
+
+const (
+	discordType = "discord"
+)
+
+type discordTypeNotifier struct {
+	WebhookURL string
+	entries    []*log.Entry
+}
+
+func newDiscordNotifier(c *cli.Context) typeNotifier {
+	n := &discordTypeNotifier{
+		WebhookURL: c.GlobalString("notification-discord-webhook"),
+	}
+
+	log.AddHook(n)
+
+	return n
+}
+
+func (n *discordTypeNotifier) sendEntries(entries []*log.Entry) {
+	// Do the sending in a separate goroutine so we don't block the main process.
+	message := ""
+	for _, entry := range entries {
+		message += entry.Time.Format("2006-01-02 15:04:05") + " (" + entry.Level.String() + "): " + entry.Message + "\r\n"
+	}
+
+	go func() {
+		webhookBody := discordWebhookBody{Content: message}
+		jsonBody, err := json.Marshal(webhookBody)
+		if err != nil {
+			fmt.Println("Failed to build JSON body for Discord notificattion: ", err)
+			return
+		}
+
+		resp, err := http.Post(n.WebhookURL, "application/json", bytes.NewBuffer([]byte(jsonBody)))
+		if err != nil {
+			fmt.Println("Failed to send Discord notificattion: ", err)
+		}
+
+		defer resp.Body.Close()
+
+		if resp.StatusCode < 200 || resp.StatusCode > 299 {
+			fmt.Println("Failed to send Discord notificattion. HTTP RESPONSE STATUS: ", resp.StatusCode)
+		}
+	}()
+}
+
+func (n *discordTypeNotifier) StartNotification() {
+	if n.entries == nil {
+		n.entries = make([]*log.Entry, 0, 10)
+	}
+}
+
+func (n *discordTypeNotifier) SendNotification() {
+	if n.entries != nil && len(n.entries) != 0 {
+		n.sendEntries(n.entries)
+	}
+	n.entries = nil
+}
+
+func (n *discordTypeNotifier) Levels() []log.Level {
+	// TODO: Make this configurable.
+	return []log.Level{
+		log.PanicLevel,
+		log.FatalLevel,
+		log.ErrorLevel,
+		log.WarnLevel,
+		log.InfoLevel,
+	}
+}
+
+func (n *discordTypeNotifier) Fire(entry *log.Entry) error {
+	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})
+	}
+	return nil
+}
+
+type discordWebhookBody struct {
+	Content string `json:"content"`
+}