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Email Integration

Send alerts via email using SMTP.

Prerequisites​

  • SMTP server access
  • Credentials for authentication

Configuration​

Create the Secret​

kubectl create secret generic smtp-credentials \
  --from-literal=host=smtp.example.com \
  --from-literal=port=587 \
  --from-literal=username=alerts@example.com \
  --from-literal=password=your-password

Create the AlertChannel​

email-channel.yaml
apiVersion: guardian.illenium.net/v1alpha1
kind: AlertChannel
metadata:
  name: ops-email
spec:
  type: email
  email:
    smtpSecretRef:
      name: smtp-credentials
      namespace: default
    from: alerts@example.com
    to:
      - oncall@example.com
      - team-leads@example.com

Email Content​

Subject Template​

spec:
  type: email
  email:
    smtpSecretRef:
      name: smtp-credentials
      namespace: default
    from: alerts@example.com
    to:
      - team@example.com
    subjectTemplate: "[{{ .Severity | upper }}] CronJob {{ .CronJobName }}: {{ .AlertType }}"

Body Template​

spec:
  type: email
  email:
    smtpSecretRef:
      name: smtp-credentials
      namespace: default
    from: alerts@example.com
    to:
      - team@example.com
    bodyTemplate: |
      CronJob Guardian Alert

      Severity: {{ .Severity | upper }}
      Type: {{ .AlertType }}
      CronJob: {{ .Namespace }}/{{ .CronJobName }}
      Time: {{ .Timestamp }}

      {{ .Message }}

      {{ if .SuggestedFix }}
      Suggested Fix:
      {{ .SuggestedFix }}
      {{ end }}

      {{ if .Logs }}
      Recent Logs:
      {{ .Logs }}
      {{ end }}

      ---
      This alert was sent by CronJob Guardian

HTML Body​

spec:
  type: email
  email:
    smtpSecretRef:
      name: smtp-credentials
      namespace: default
    from: alerts@example.com
    to:
      - team@example.com
    bodyTemplate: |
      <html>
      <body style="font-family: Arial, sans-serif;">
        <h2 style="color: {{ if eq .Severity "critical" }}#dc3545{{ else if eq .Severity "warning" }}#ffc107{{ else }}#17a2b8{{ end }};">
          {{ .Title }}
        </h2>
        <table>
          <tr><td><strong>Severity:</strong></td><td>{{ .Severity | upper }}</td></tr>
          <tr><td><strong>CronJob:</strong></td><td>{{ .Namespace }}/{{ .CronJobName }}</td></tr>
          <tr><td><strong>Time:</strong></td><td>{{ .Timestamp }}</td></tr>
        </table>
        <p>{{ .Message }}</p>
        {{ if .SuggestedFix }}
        <h3>Suggested Fix</h3>
        <pre style="background: #f5f5f5; padding: 10px;">{{ .SuggestedFix }}</pre>
        {{ end }}
      </body>
      </html>

Recipients​

Severity-Based Routing​

Use multiple channels with different recipients:

critical-email.yaml
apiVersion: guardian.illenium.net/v1alpha1
kind: AlertChannel
metadata:
  name: critical-email
spec:
  type: email
  email:
    smtpSecretRef:
      name: smtp-credentials
      namespace: default
    from: alerts@example.com
    to:
      - oncall@example.com
      - leadership@example.com
    subjectTemplate: "[CRITICAL] CronJob {{ .CronJobName }} requires immediate attention"
---
apiVersion: guardian.illenium.net/v1alpha1
kind: AlertChannel
metadata:
  name: warning-email
spec:
  type: email
  email:
    smtpSecretRef:
      name: smtp-credentials
      namespace: default
    from: alerts@example.com
    to:
      - team@example.com
    subjectTemplate: "[Warning] CronJob {{ .CronJobName }}: {{ .AlertType }}"

Rate Limiting​

Configure rate limits at the AlertChannel level:

spec:
  type: email
  email:
    smtpSecretRef:
      name: smtp-credentials
      namespace: default
    from: alerts@example.com
    to:
      - team@example.com
  rateLimiting:
    burstLimit: 10
    maxAlertsPerHour: 50

Complete Example​

email-complete.yaml
apiVersion: guardian.illenium.net/v1alpha1
kind: AlertChannel
metadata:
  name: ops-email
spec:
  type: email
  email:
    smtpSecretRef:
      name: smtp-credentials
      namespace: default
    from: cronjob-guardian@example.com
    to:
      - platform-team@example.com
    subjectTemplate: "[{{ .Severity | upper }}] {{ .CronJobName }} - {{ .AlertType }}"
    bodyTemplate: |
      CronJob Guardian Alert

      Title: {{ .Title }}
      CronJob: {{ .Namespace }}/{{ .CronJobName }}
      Severity: {{ .Severity | upper }}

      {{ .Message }}

      {{ if .SuggestedFix }}
      Suggested Fix:
      {{ .SuggestedFix }}
      {{ end }}
  rateLimiting:
    burstLimit: 10
    maxAlertsPerHour: 50

Testing​

curl -X POST http://localhost:8080/api/v1/channels/ops-email/test

Troubleshooting​

Connection Failed​

  • Verify SMTP host and port in secret
  • Check network connectivity from cluster
  • Verify TLS settings match server requirements

Authentication Failed​

  • Check username and password in secret
  • Verify auth type matches server (plain, login, crammd5)

Emails Not Received​

  • Check spam folders
  • Verify recipient addresses
  • Check SMTP server logs
  • Ensure from address is allowed by server

Rate Limiting​

Emails being dropped due to rate limits:

  • Increase rate limits if needed
  • Use suppressDuplicatesFor on monitors
  • Consider routing only critical alerts to email