Kubernetes extension plugin Cluster DNS installation

Kubernetes extension plugin Cluster DNS installation

Back to master machine 10.99.0.10

The directory where the skydns configuration file is located (this example uses the file in the getting-started-guides directory)

[root@vultr ~]# find -name *skydns*

./kubernetes/cluster/libvirt-coreos/skydns-rc.yaml

./kubernetes/cluster/libvirt-coreos/skydns-svc.yaml

./kubernetes/cluster/gce/coreos/kube-manifests/addons/dns/skydns-rc.yaml

./kubernetes/cluster/gce/coreos/kube-manifests/addons/dns/skydns-svc.yaml

./kubernetes/cluster/juju/layers/kubernetes/templates/skydns-rc.yml

./kubernetes/cluster/juju/layers/kubernetes/templates/skydns-svc.yml

./kubernetes/docs/getting-started-guides/coreos/azure/addons/skydns-rc.yaml

./kubernetes/docs/getting-started-guides/coreos/azure/addons/skydns-svc.yaml

Create a working directory

cd ~/kubernetes/docs/getting-started-guides/coreos/azure/addons/

mkdir -p ~/workspace/skydns

cp skydns-* ~/workspace/skydns/

cd ~/workspace/skydns

ls -l

Modify skydns-rc.yaml and skydns-svc.yaml

sed -i "s/replicas: 3/replicas: 1/" skydns-rc.yaml

sed -i "s/kube.local/cluster.local/" skydns-rc.yaml

sed -i "s/kube-00/10.99.0.10/" skydns-rc.yaml

sed -i "s/localhost/127.0.0.1/" skydns-rc.yaml

sed -i "s/kube.local/cluster.local./" skydns-rc.yaml

sed -i "s/kubernetes.default.svc.kube.local/kubernetes.default.svc.cluster.local/" skydns-rc.yaml

sed -i "s/10.16.0.3/172.16.66.66/" skydns-svc.yaml

Create Kubernetes DNS

[root@vultr skydns]#kubectl create -f skydns-rc.yaml

replicationcontroller "kube-dns-v9" created

[root@vultr skydns]# kubectl get pod --selector k8s-app=kube-dns --namespace=kube-system

NAME READY STATUS RESTARTS AGE

kube-dns-v9-hgnfh 4/4 Running 0 16s

[root@vultr skydns]# kubectl create -f skydns-svc.yaml

kubectl get service -l k8s-app=kube-dns --namespace=kube-systemservice "kube-dns" created

[root@vultr skydns]# kubectl get service -l k8s-app=kube-dns --namespace=kube-system

NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE

kube-dns 172.16.66.66 <none> 53/UDP,53/TCP 2s

kubectl cluster-info

return result

Kubernetes master is running at http://localhost:8080

KubeDNS is running at http://localhost:8080/api/v1/proxy/namespaces/kube-system/services/kube-dns

actually visit

http://master机器IP:8080/api/v1/namespaces/kube-system/services/kube-dns

can see details

{
  "kind": "Service",
  "apiVersion": "v1",
  "metadata": {
    "name": "kube-dns",
    "namespace": "kube-system",
    "selfLink": "/api/v1/namespaces/kube-system/services/kube-dns",
    ... ...

修改各节点机器上的kubelet配置

vi /etc/sysconfig/kubelet

--cluster-dns=172.16.66.66

--cluster-domain=cluster.local

重启节点机器上的kubelet

systemctl restart kubelet

systemctl status -l kubelet

创建一个测试pod

echo " apiVersion: v1

kind: ReplicationController

metadata:

name: tomcat

spec:

replicas: 1

template:

metadata:

labels:

app: tomcat

spec:

containers:

- name: tomcat

image: tomcat" > tomcat.yaml

cat tomcat.yaml

kubectl --server=10.99.0.10:8080 create -f tomcat.yaml

kubectl get pod

进入到pod中的第一个容器

kubectl exec tomcat-4d33v -i -t -- bash

查看DNS

cat /etc/resolv.conf

search default.svc.cluster.local svc.cluster.local cluster.local

nameserver 172.16.66.66

options ndots:5

之前创建的pod DNS未改变，需要删除之后重建

kubectl --server=10.99.0.10:8080 delete -f test-1.yaml

kubectl --server=10.99.0.10:8080 delete -f test-2.yaml

kubectl --server=10.99.0.10:8080 delete -f test-3.yaml

kubectl --server=10.99.0.10:8080 delete -f test-4.yaml

kubectl --server=10.99.0.10:8080 create -f test-1.yaml

kubectl --server=10.99.0.10:8080 create -f test-2.yaml

kubectl --server=10.99.0.10:8080 create -f test-3.yaml

kubectl --server=10.99.0.10:8080 create -f test-4.yaml

kubectl --server=10.99.0.10:8080 get pods

进入test-1-cqc6p点的第一个容器查看DNS

kubectl exec test-1-cqc6p -i -t -- bash

cat /etc/resolv.conf

search default.svc.cluster.local svc.cluster.local cluster.local

nameserver 172.16.66.66

options ndots:5

expose 创建tomcat service

kubectl expose replicationcontroller tomcat --port=8080 --target-port=8099

Kubernetes extension plugin Cluster DNS installation

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