[feat] automatic pre-seeding of `resolver-addresses` pointing to system nameservers

[defanator]

Is your feature request related to a problem? Please describe.

Specifying resolver-addresses manually for every NIC deployment could be challenging in modern containerized world.

Describe the solution you'd like

A way to populate resolver directive with nameservers from system/pod, as it's done e.g. in official nginx docker images: https://github.com/nginxinc/docker-nginx/blob/master/entrypoint/15-local-resolvers.envsh

(something like resolver-addresses: auto ?)

Describe alternatives you've considered

Adding resolver-addresses to corresponding ConfigMaps after initial deploying of NIC, once all deployments + pods are created and nameservers could be pulled from /etc/resolv.conf of a corresponding installation.

Additional context

N/A

[github-actions]

Hi @defanator thanks for reporting!

Be sure to check out the docs and the Contributing Guidelines while you wait for a human to take a look at this 🙂

Cheers!

[defanator]

Also, with recent auto re-resolving support in nginx/foss, the resolver-addresses should be supported for NIC with nginx/foss installations as well: https://blog.nginx.org/blog/dynamic-dns-resolution-open-sourced-in-nginx

[AlexFenlon]

Hi @defanator,

The default for the resolver in Kubernetes would bekube-dns.kube-system.svc.cluster.local if we want this.