Configure DNS record TTL (Time-To-Live)¶

An optional annotation external-dns.alpha.kubernetes.io/ttl is available to customize the TTL value of a DNS record.
TTL is specified as an integer encoded as string representing seconds.

To configure it, simply annotate a service/ingress, e.g.:

apiVersion: v1
kind: Service
metadata:
  annotations:
    external-dns.alpha.kubernetes.io/hostname: nginx.external-dns-test.my-org.com.
    external-dns.alpha.kubernetes.io/ttl: "60"
  ...

TTL can also be specified as a duration value parsable by Golang time.ParseDuration:

apiVersion: v1
kind: Service
metadata:
  annotations:
    external-dns.alpha.kubernetes.io/hostname: nginx.external-dns-test.my-org.com.
    external-dns.alpha.kubernetes.io/ttl: "1m"
  ...

Both examples result in the same value of 60 seconds TTL.

TTL must be a positive value.

Providers¶

PRs welcome!

Notes¶

When the external-dns.alpha.kubernetes.io/ttl annotation is not provided, the TTL will default to 0 seconds and endpoint.TTL.isConfigured() will be false.

AWS Provider¶

The AWS Provider overrides the value to 300s when the TTL is 0.
This value is a constant in the provider code.

Azure¶

TTL value should be between 1 and 2,147,483,647 seconds.
By default it will be 300s.

CloudFlare Provider¶

CloudFlare overrides the value to “auto” when the TTL is 0.

DigitalOcean Provider¶

The DigitalOcean Provider overrides the value to 300s when the TTL is 0.
This value is a constant in the provider code.

DNSimple Provider¶

The DNSimple Provider default TTL is used when the TTL is 0. The default TTL is 3600s.

Google Provider¶

Previously with the Google Provider, TTL’s were hard-coded to 300s.
For safety, the Google Provider overrides the value to 300s when the TTL is 0.
This value is a constant in the provider code.

For the moment, it is impossible to use a TTL value of 0 with the AWS, DigitalOcean, or Google Providers.
This behavior may change in the future.

Linode Provider¶

The Linode Provider default TTL is used when the TTL is 0. The default is 24 hours

TransIP Provider¶

The TransIP Provider minimal TTL is used when the TTL is 0. The minimal TTL is 60s.

UltraDNS¶

The UltraDNS provider minimal TTL is used when the TTL is not provided. The default TTL is account level default TTL, if defined, otherwise 24 hours.