AAAA records are being deleted and added on every run

[juusujanar]

What happened:

external-dns is constantly deleting and re-adding AAAA records of the ingress objects, even though there are no changes made. Only one instance of external-dns is running on GKE and managing the DNS records. Services are running behind ingress-nginx LoadBalancer service, which is in DualStack (IPv4 and IPv6) mode.

external-dns-cd777d94d-p6v66 external-dns time="2023-09-22T11:38:33Z" level=debug msg="Endpoints generated from ingress: default/svcname: [example.org 0 IN A  1.1.1.1 [] example.org 0 IN AAAA  2600:1900::0 [] example.org 0 IN A  1.1.1.1 [] example.org 0 IN AAAA  2600:1900::0 []]"
external-dns-cd777d94d-p6v66 external-dns time="2023-09-22T11:38:33Z" level=debug msg="Removing duplicate endpoint example.org 0 IN A  1.1.1.1 []"
external-dns-cd777d94d-p6v66 external-dns time="2023-09-22T11:38:33Z" level=debug msg="Removing duplicate endpoint example.org 0 IN AAAA  2600:1900::0 []"
external-dns-cd777d94d-p6v66 external-dns time="2023-09-22T11:38:34Z" level=info msg="Del records: aaaa-example.org. TXT [\"heritage=external-dns,external-dns/owner=gke-production,external-dns/resource=ingress/default/svcname\"] 300"
external-dns-cd777d94d-p6v66 external-dns time="2023-09-22T11:38:34Z" level=info msg="Del records: example.org. AAAA [2600:1900::0] 300"
external-dns-cd777d94d-p6v66 external-dns time="2023-09-22T11:38:34Z" level=info msg="Add records: aaaa-example.org. TXT [\"heritage=external-dns,external-dns/owner=gke-production,external-dns/resource=ingress/default/svcname\"] 300"
external-dns-cd777d94d-p6v66 external-dns time="2023-09-22T11:38:34Z" level=info msg="Add records: example.org. AAAA [2600:1900::0] 300"

What you expected to happen:

No changes are made to the DNS records.

How to reproduce it (as minimally and precisely as possible):

1. Run ingress-nginx with dual-stack loadbalancer.
2. Run external-dns to Google Cloud DNS.
3. Add an ingress object.

Anything else we need to know?:

Environment:

• External-DNS version (use external-dns --version): registry.k8s.io/external-dns/external-dns:v0.13.6, Helm chart 1.13.1.
• DNS provider: Google Cloud DNS
• Others:

Debug doesn't show any other useful information, apart from finding duplicate endpoints. Issue also exists in older versions (tested up to 1.12.0).

[romankydybets]

same behavior

[growse]

I had this issue with a LoadBalancer service, but discovered that it was because I actually had two services which both had the external-dns.alpha.kubernetes.io/hostname set to the same value, and with the same externalIP (this was a carry-over from pre-1.26 where you couldn't share UDP / TCP on the same service).

I consolidated onto a single service, and the problem went away.

[k8s-triage-robot]

The Kubernetes project currently lacks enough contributors to adequately respond to all issues.

This bot triages un-triaged issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue as fresh with /remove-lifecycle stale
• Close this issue with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues.

This bot triages un-triaged issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue as fresh with /remove-lifecycle rotten
• Close this issue with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle rotten

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Reopen this issue with /reopen
• Mark this issue as fresh with /remove-lifecycle rotten
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/close not-planned

[k8s-ci-robot]

@k8s-triage-robot: Closing this issue, marking it as "Not Planned".

In response to this:

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Reopen this issue with /reopen
• Mark this issue as fresh with /remove-lifecycle rotten
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/close not-planned

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.