80 lines
1.7 KiB
Markdown
80 lines
1.7 KiB
Markdown
# Deploying the DNS Cluster Add-on
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In this lab you will deploy the [DNS add-on](https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/) which provides DNS based service discovery to applications running inside the Kubernetes cluster.
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## The DNS Cluster Add-on
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Deploy the `kube-dns` cluster add-on:
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```
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kubectl create -f https://storage.googleapis.com/kubernetes-the-hard-way/kube-dns.yaml
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```
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> output
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```
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serviceaccount "kube-dns" created
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configmap "kube-dns" created
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service "kube-dns" created
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deployment "kube-dns" created
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```
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List the pods created by the `kube-dns` deployment:
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```
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kubectl get pods -l k8s-app=kube-dns -n kube-system
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```
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> output
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```
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NAME READY STATUS RESTARTS AGE
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kube-dns-3097350089-gq015 3/3 Running 0 20s
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kube-dns-3097350089-q64qc 3/3 Running 0 20s
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```
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## Verification
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Create a `busybox` deployment:
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```
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kubectl run busybox --image=busybox --command -- sleep 3600
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```
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List the pod created by the `busybox` deployment:
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```
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kubectl get pods -l run=busybox
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```
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> output
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```
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NAME READY STATUS RESTARTS AGE
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busybox-2125412808-mt2vb 1/1 Running 0 15s
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```
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Retrieve the full name of the `busybox` pod:
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```
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POD_NAME=$(kubectl get pods -l run=busybox -o jsonpath="{.items[0].metadata.name}")
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```
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Execute a DNS lookup for the `kubernetes` service inside the `busybox` pod:
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```
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kubectl exec -ti $POD_NAME -- nslookup kubernetes
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```
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> output
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```
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Server: 10.32.0.10
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Address 1: 10.32.0.10 kube-dns.kube-system.svc.cluster.local
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Name: kubernetes
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Address 1: 10.32.0.1 kubernetes.default.svc.cluster.local
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```
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Next: [Smoke Test](13-smoke-test.md)
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