Skip to content

Notification Templates

Use templating to transform raw technical metrics—like heap usage or slow request counts—into human-readable alerts. By incorporating dynamic data, your team can diagnose issues directly from a Slack message or email without opening the dashboard first.

Alert Rule Annotations

Annotations are the primary way to pass FusionReactor metadata into your alerts.

  • Purpose: Use them for the Summary (what happened) and Description (why it matters).
  • Dynamic Values: Use Go templating to display specific FR metrics. For example, show the exact millisecond duration of a slow request or the specific URL that triggered the alert.

Learn more

Annotations in Alerting

Alert Rule Labels

Labels categorize your FusionReactor instances (such as, app_name, environment, or server_id).

  • Purpose: Use labels to route alerts to different teams (such as, tier: critical goes to PagerDuty, while tier: warning goes to Slack).
  • Important: Avoid putting highly variable data (like a dynamic timestamp or unique Request ID) in labels. This creates cardinality issues, making it harder to track alert history. Keep these values in Annotations instead.

Learn more

Labelling Alerts

Notification Templates

Managed in the Contact Points section, these define the wrapper or envelope for your notifications.

  • Purpose: Ensure every Slack alert from FusionReactor has the same layout, icon, or link to your runbooks.
  • Centralization: Instead of writing the same Slack block for 50 different alert rules, you define it once in a Notification Template and reuse it across all FusionReactor alerts.

Learn more

Create Notification Templates

Which one should I use?

Goal Use This Example Syntax
Show the current CPU % Annotation Current Value: {{ $values.B.Value }}%
Direct to the correct Slack channel Label team: devops
Add a link to the FR Instance Annotation [View Instance]({{ .Labels.fr_url }})
Bold the Title for all Slack alerts Notification Template {{ define "my.title" }} *ALERT:* {{ .Labels.alertname }} {{ end }}

Tip

For a practical example of templating, refer to this tutorial.