Initial structure

internal/alerts/discord.go

@@ -0,0 +1,56 @@
+package alerts
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/jasper/quptime/internal/config"
+)
+
+// discordTimeout caps how long a single webhook POST is allowed to
+// take.
+const discordTimeout = 10 * time.Second
+
+// discordPayload is the minimum shape the Discord webhook API
+// accepts. We do not use embeds — plain text keeps the payload
+// trivial to read in operator-side logs.
+type discordPayload struct {
+	Content string `json:"content"`
+}
+
+// sendDiscord posts msg.Subject + body to the configured webhook URL.
+func sendDiscord(a *config.Alert, msg Message) error {
+	if a.DiscordWebhook == "" {
+		return errors.New("discord webhook url not set")
+	}
+
+	content := msg.Subject + "\n```\n" + msg.Body + "\n```"
+	raw, err := json.Marshal(discordPayload{Content: content})
+	if err != nil {
+		return err
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), discordTimeout)
+	defer cancel()
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, a.DiscordWebhook, bytes.NewReader(raw))
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("discord webhook: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 300 {
+		body, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		return fmt.Errorf("discord webhook status %d: %s", resp.StatusCode, string(body))
+	}
+	return nil
+}