Feature Request: Expose dnsConfig in Helm Chart for Custom DNS Configuration

[torredil]

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

This feature request is motivated by issues faced during cluster scaling operations, where DNS throttling can lead to significant disruptions. Specifically, the controller can get throttled by EC2 security group connection tracking conntrack_allowance_exceeded_by_host due to excessive DNS queries.

Implementing a way to adjust controller pod DNS settings via the chart would offer a straightforward and generic solution to mitigate such issues.

Describe the solution you'd like in detail

A user should be able to configure DNS settings in the Helm chart values like so:

dnsConfig:
  options:
    - name: ndots
      value: "2"

The default ndots value is 5, which can lead to unnecessary DNS traffic and delays in resolving names. A value of 2 can be a good optimization for the scenario described above given the controller predominantly makes DNS queries to AWS endpoints or fully qualified domain names rather than in-cluster services.

Additional context

https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/

/feature