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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

  • AWS (Route53)
  • Azure
  • Cloudflare
  • DigitalOcean
  • DNSimple
  • Google
  • InMemory
  • Linode
  • TransIP
  • RFC2136
  • Vultr
  • UltraDNS

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.

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.

Vultr Provider

The Vultr provider minimal TTL is used when the TTL is 0. The default is 1 hour.

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.

Last update: March 15, 2022
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