Customize Grafana alert emails

• The alert email sent by Grafana can be customized. The default alert email looks something like this

• Even though the default alert email is very informative, there might be some customization requirements like removal or change of Grafana logo, change in colors etc.

Notification template in Grafana

• Grafana alert content is created from Go templating variables.
• The official guide to understand Go templating language used Grafana alerts can be found at https://grafana.com/docs/grafana/latest/alerting/configure-notifications/template-notifications/using-go-templating-language/

Let us explore the options to customize Grafana alert content

Option 1 - Edit contact point Message (Limited customization)

• In the email contact point editing screen there is a provision to customize email message as shown below

• The default email message will be replaced with the “Message” input of the contact point configuration screen
• Template variables can be used to render the alert information in the email message
• For example, we can use a custom email message something like

Testing out the custom email message

{{ range .Alerts }}
  Status: {{ .Status }}
  Starts at: {{ .StartsAt }}
  Name: {{ .Labels.alertname }}
  
  Values:
  {{ range $refID, $value := .Values }}
    {{ $refID }}={{ $value }}
  {{ end }}
{{ end }}

• The new alert will look like the following

• The Grafana logo, footer, colors etc cannot be customized with this approach. For complete customization, the email template HTML file in Grafana needs to be edited

Option 2 - Edit the Email alert HTML template

• The email alert template is present as the file “ng_alert_notification.html” in the grafana→public→emails folder (Example: “C:\Program Files\GrafanaLabs\grafana\public\emails\ng_alert_notification.html”)
• All the email HTML code can be edited in this file. Keep a backup of the original HTML file for safety before editing
• HTML content can be easily commented out by surrounding with {{/* */}} tags
• Customization like removing logo, changing logo URL, font size, colors, removing content, footers, adding extra content etc., can be done very easily
• Restart Grafana after making changes
• If email is not sent after making changes in HTML, check Grafana logs located in the grafana.log file (”C:\Program Files\GrafanaLabs\grafana\data\log\grafana.log”) to check if there are errors in the email HTML file.
• An example email after commenting out Grafana logo, Alert folder heading and Number of alerts heading can be shown below

Video

Video on this post can be seen here

References

• Grafana Go templating language guide - https://grafana.com/docs/grafana/latest/alerting/configure-notifications/template-notifications/using-go-templating-language/