Use explicit dns config

[stephen-soltesz]

This change removes the initContainer that manually overwrites the content of /etc/resolv.conf in favor of using the native k8s support for specifying the dnsPolicy and dnsConfig -- see also: https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/

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This change is 

[stephen-soltesz]

See also: #542

[nkinkade]

Do we really want to explicitly and completely override all cluster-local resolution

Reviewed 1 of 1 files at r2.
Reviewable status: 0 of 1 LGTMs obtained

a discussion (no related file):
Thank you for this. This is far cleaner and explicit than the initContainer.

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[stephen-soltesz]

I think the answer to your question is: we do not want to override all cluster-local resolution. And, we do not know how to work with the cluster-local resolution yet.

I would prefer (almost always) to work with the system's way of doing things rather than go against the grain and build custom strategies.

In this case, I think we don't know how to do that yet while preserving our multus network configuration for experiments. If we could do both, that would be welcome.

Reviewable status: 0 of 1 LGTMs obtained