cluster-add-on-dns.md

Cluster Add-on: DNS

Kubernetes offers a DNS cluster add-on that provides DNS A and SRV records for Kubernetes services. The heavy lifting is done by SkyDNS, an etcd backed DNS server that supports dynamic updates from the Kubernetes API.

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Create the SkyDNS replication controller configuration:

curl -O https://storage.googleapis.com/configs.kuar.io/skydns-rc.yaml

Edit the SkyDNS rc config:

PROJECT_ID=$(gcloud compute ssh node0 --command \
  "curl -H 'Metadata-Flavor: Google' \
  http://metadata.google.internal/computeMetadata/v1/project/project-id")

sed -i -e "s/PROJECT_ID/${PROJECT_ID}/g;" skydns-rc.yaml

Create the SkyDNS replication controller:

kubectl create -f skydns-rc.yaml

Next create the SkyDNS service:

curl -O https://storage.googleapis.com/configs.kuar.io/skydns-svc.yaml

kubectl create -f skydns-svc.yaml

Validate

kubectl get rc --all-namespaces

Wait for "Running" status

kubectl get pods --namespace=kube-system --watch-only

Test DNS lookups

curl -O https://storage.googleapis.com/configs.kuar.io/busybox-pod.yaml

kubectl create -f busybox-pod.yaml

kubectl get pods busybox

kubectl exec busybox -- nslookup kubernetes