aws_sd provider does not properly match on subdomain suffix

[Kilowhisky]

What happened: I'm attempting to utilize the Bitnami Redis helm chart that uses the template <instance>.<service>.<suffix> and it is unable to locate a match of the format <suffix> because this line parses the hostname into <service>.<suffix>.

https://github.com/kubernetes-sigs/external-dns/blob/7ddc9daba70794e7a9fa77e664b5d60e1e8322f6/provider/awssd/aws_sd.go#L647-L652

https://github.com/kubernetes-sigs/external-dns/blob/7ddc9daba70794e7a9fa77e664b5d60e1e8322f6/provider/awssd/aws_sd.go#L634-L644

NOTE the regular Route53 AWS provider behaves properly

What you expected to happen:

It should really walk back on the dots until it finds a match so for example.

1. Search for <service>.<suffix>
2. Search for <suffix>

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

1. Create a AWS Cloudmap of something like mydomain.private
2. Try and register a instance with external DNS of my-node.my-service.mydomain.private
3. Watch it fail to find a match.

Anything else we need to know?:

The regular Route53 AWS provider behaves properly

Environment:

• External-DNS version (use external-dns --version): 0.13.5
• DNS provider: AWS Route53 & AWS CloudMap
• Others:

[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/test-infra repository.