Caching DNS requests on cluster nodes

In Deckhouse Kubernetes Platform, you can deploy a local caching DNS server on each cluster node. It exports metrics to Prometheus for visualization in a Grafana dashboard.

This feature is implemented by the node-local-dns module. The module consists of the original CoreDNS deployed as a DaemonSet on all cluster nodes, along with a network configuration algorithm and iptables rules.

Detailed information about the problems that caching DNS-server allows to solve and the principle of its work is available in Caching DNS server in a cluster.

Example custom DNS configuration in a Pod

apiVersion: v1
kind: Pod
metadata:
  name: dns-example
spec:
  dnsPolicy: "None"
  dnsConfig:
    nameservers:
      - 169.254.20.10
  containers:
    - name: test
      image: nginx

For details on DNS configuration, refer to the Kubernetes documentation.