var routeSelector = newRouteSelector(address)
    dns[PROXY_A_HOST] = dns.allocate(1)
    dns[PROXY_B_HOST] = dns.allocate(1)

    // Mark the ProxyA route as failed.
    val selection = routeSelector.next()
    dns.assertRequests(PROXY_A_HOST)
    val route = selection.next()
    assertRoute(route, address, proxyA, dns.lookup(PROXY_A_HOST, 0), PROXY_A_PORT)
    routeDatabase.failed(route)

# kube-dns

`kube-dns` schedules DNS Pods and Service on the cluster, other pods in cluster
can use the DNS Service’s IP to resolve DNS names.

* [Administrators guide](http://kubernetes.io/docs/admin/dns/)
* [Code repository](http://www.github.com/kubernetes/dns)

## Manually scale kube-dns Deployment

kube-dns creates only one DNS Pod by default. If
[dns-horizontal-autoscaler](../../dns-horizontal-autoscaler/)

		# svc2
		add chain ip kube-proxy service-42NFTM6N-ns2/svc2/tcp/p80
		add rule ip kube-proxy service-42NFTM6N-ns2/svc2/tcp/p80 ip daddr 172.30.0.42 tcp dport 80 ip saddr != 10.0.0.0/8 jump mark-for-masquerade
		add rule ip kube-proxy service-42NFTM6N-ns2/svc2/tcp/p80 numgen random mod 1 vmap { 0 : goto endpoint-SGOXE6O3-ns2/svc2/tcp/p80__10.180.0.2/80 }
		add chain ip kube-proxy external-42NFTM6N-ns2/svc2/tcp/p80

    kubernetes.io/name: "KubeDNSUpstream"
spec:
  ports:
  - name: dns
    port: 53
    protocol: UDP
    targetPort: 53
  - name: dns-tcp
    port: 53
    protocol: TCP
    targetPort: 53
  selector:
    k8s-app: kube-dns
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: node-local-dns
  namespace: kube-system
  labels:
    addonmanager.kubernetes.io/mode: Reconcile
data:
  Corefile: |

			switch r.Question[0].Qtype {
			case dns.TypeA:
				msg.Answer = append(msg.Answer, &dns.A{
					Hdr: dns.RR_Header{Name: domain, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.ttl},
					A:   net.ParseIP(fmt.Sprintf("10.0.0.%d", c)),
				})
			case dns.TypeAAAA:
				// set a long TTL for AAAA
				msg.Answer = append(msg.Answer, &dns.AAAA{
					Hdr:  dns.RR_Header{Name: domain, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.ttl * 10},

				-A KUBE-SVC-GNZBNJ2PO5MGZ6GT -m comment --comment ns2/svc2:p80 -j KUBE-SEP-RS4RBKLTHTF2IUXJ
				-A KUBE-SEP-RS4RBKLTHTF2IUXJ -m comment --comment ns2/svc2:p80 -s 10.180.0.2 -j KUBE-MARK-MASQ
				-A KUBE-SEP-RS4RBKLTHTF2IUXJ -m comment --comment ns2/svc2:p80 -m tcp -p tcp -j DNAT --to-destination 10.180.0.2:80

// limitations under the License.

package client

import (
	"net"
	"time"

	"github.com/miekg/dns"
)

type dnsProxy struct {
	serveMux *dns.ServeMux
	server   *dns.Server

	// This is the upstream Client used to make upstream DNS queries
	// in case the data is not in our name table.
	upstreamClient *dns.Client
	protocol       string
	resolver       *LocalDNSServer
}

# Nodelocal DNS Cache

Using NodeLocal DNSCache in Kubernetes clusters(https://kubernetes.io/docs/tasks/administer-cluster/nodelocaldns/).
This addon runs a node-local-dns pod on all cluster nodes. The pod runs CoreDNS as the dns cache. It runs with `hostNetwork:True` and creates a dedicated dummy interface with a link local ip(169.254.20.10/32 by default) to listen for DNS queries. The cache instances connect to clusterDNS in case of cache misses.

Eoin Fennessy <******@****.***> 1715615475 +0100

    .url("https://dns.google/dns-query".toHttpUrl())
    .bootstrapDnsHosts(InetAddress.getByName("8.8.4.4"), InetAddress.getByName("8.8.8.8"))
    .build()

  val client = bootstrapClient.newBuilder().dns(dns).build()
```