add target filters based on network

[tobikris]

Description

I have implemented the possibility to filter the targets discovered from sources. My usecase is the OCI loadbalancer that assigns both a private and public IP address to the service. If both are published in public DNS, the record is useless.
You can filter the generated targets by their networks
using --target-net-filter=10.0.0.0/8 or --exclude-target-net=10.0.0.0/8.

I guess there might be more target filters in the future, which is why I tried to stay as flexible as possible. I tried to add this change to the relevant docs section.

Checklist

• Unit tests updated
• End user documentation updated

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: tobikris / name: Tobias Krischer (cd31174)

[k8s-ci-robot]

Welcome @tobikris!

It looks like this is your first PR to kubernetes-sigs/external-dns 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-sigs/external-dns has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[tobikris]

/assign @njuettner

[k8s-triage-robot]

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

This bot triages issues and PRs 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 or PR as fresh with /remove-lifecycle stale
• Mark this issue or PR as rotten with /lifecycle rotten
• Close this issue or PR with /close
• Offer to help out with Issue Triage

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

/lifecycle stale

[tobikris]

/remove-lifecycle stale

[tobikris]

Hey @njuettner, can you please give me an estimate when this PR could be reviewed?

Thanks for your time!

[njuettner]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: njuettner, tobikris

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [njuettner]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[benarnold42]

This would be really helpful, if also a PR for filtering for private DNS zones in OCI, would get merged. E.g.: #2673

[HerrmannHinz]

@njuettner any release date for this?