ExternalDNS

ExternalDNS watches Kubernetes resources and creates/updates DNS records in your DNS provider.

Why use it

• Reduces manual DNS updates.
• Keeps records aligned with route and service changes.
• Improves repeatability across environments.

Typical annotation pattern

Use explicit hostname annotation on your route/service when required by your policy:

metadata:
  annotations:
    external-dns.alpha.kubernetes.io/hostname: app.example.com

Best practices

• Use domain filters to limit managed zones.
• Prefer explicit ownership policy for records.
• Keep low-privilege credentials for DNS providers.

Troubleshooting quick checks

• Resource has expected hostname annotation.
• ExternalDNS logs show source object detection.
• DNS provider zone allows writes for target record.

Further reading

• ExternalDNS documentation
• ExternalDNS annotations