Of Stack

Detailed steps for installing and configuring the k8s cluster in centos 7

  • 2020-06-15 11:00:11
  • OfStack

Configuration Background

kubernetes is an open source container cluster management system of google, providing application deployment, maintenance, extension mechanism and other functions. Using kubernetes can facilitate the management of containerized applications running across the cluster. k8s (there are 8 letters between k and s)

Why use a complex docker cluster management tool like kubernetes? 1 I started to get in touch with swarm built in docker, which is a very simple and fast tool to complete the docker clustering function. However, when using es17EN1.13 built-in swarm for clustering, vip load balancing did not correctly map the port to the external network, or the address was occupied, which was unfavorable to the requirements of high availability. However, no solution was found, so we had to switch to k8s.

Experimental environment

Tencent cloud centos7. 3, 64

The installation 


yum-config-manager --add-repo https://docs.docker.com/v1.13/engine/installation/linux/repo_files/centos/docker.repo 
yum makecache fast 
yum -y install docker-engine-1.13.1 
yum install epel-release -y 
yum remove -y docker-engine* 
yum install -y kubernetes etcd docker flannel

Modify configuration file

Note the following 10.135.163.237 switch to your own server ip 


sed -i "s/localhost:2379/10.135.163.237:2379/g" /etc/etcd/etcd.conf

sed -i "s/localhost:2380/10.135.163.237:2380/g" /etc/etcd/etcd.conf

sed -i "s/10.135.163.237:2379/10.135.163.237:2379,http:\/\/127.0.0.1:2379/g" /etc/etcd/etcd.conf


sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/kubernetes/apiserver

sed -i "s/--insecure-bind-address=127.0.0.1/--insecure-bind-address=0.0.0.0/g" /etc/kubernetes/apiserver

sed -i "s/--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota/--admission_control=NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota/g" /etc/kubernetes/apiserver



sed -i "s/--hostname-override=127.0.0.1/--hostname-override=10.135.163.237/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/kubelet


sed -i "s/--address=127.0.0.1/--address=0.0.0.0/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/config

sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/sysconfig/flanneld

Modify host 


vi /etc/hosts 
10.135.163.237 k8s_master

Add the network 


systemctl enable etcd.service

systemctl start etcd.service

etcdctl mk //atomic.io/network/config '{"Network":"172.17.0.0/16"}'

Start the service 


service docker start 
for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler kube-proxy kubelet docker flanneld ; do systemctl restart $SERVICES; systemctl enable $SERVICES; systemctl status $SERVICES; done;

The first demo

Prepare file a.yaml 


apiVersion: extensions/v1beta1 
kind: Deployment 
metadata: 
 name: my-app
spec: 
 replicas: 2
 template:
 metadata:
 labels:
 app: my-app
 spec:
 containers:
 - name: my-app
 image: registry.alauda.cn/yubang/paas_base_test
 ports:
 - containerPort: 80
 command: ["/bin/bash", "/var/start.sh"] 
 resources: 
  limits: 
  cpu: 0.5 
  memory: 64Mi

Prepare file b.yaml 


apiVersion: v1 
kind: Service 
metadata: 
 name: my-app-svc
 labels:
 app: my-app
spec: 
 ports:
 - port: 80
 targetPort: 80
 nodePort: 30964
 type: NodePort
 selector:
 app: my-app

Create a service 


kubectl create -f a.yaml --validate 
kubectl create -f b.yaml --validate

Remove the service 


kubectl delete -f a.yaml 
kubectl delete -f b.yaml

Add child nodes

Install the software 


yum-config-manager --add-repo https://docs.docker.com/v1.13/engine/installation/linux/repo_files/centos/docker.repo 
yum makecache fast 
yum -y install docker-engine-1.13.1 
yum install epel-release -y 
yum remove -y docker-engine* 
yum install -y kubernetes docker flannel

Modify configuration file (10.135.163.237 for master node ip, 139.199.0.29 for current node ip) 


sed -i "s/localhost:2379/10.135.163.237:2379/g" /etc/etcd/etcd.conf

sed -i "s/localhost:2380/10.135.163.237:2380/g" /etc/etcd/etcd.conf

sed -i "s/10.135.163.237:2379/10.135.163.237:2379,http:\/\/127.0.0.1:2379/g" /etc/etcd/etcd.conf


sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/kubernetes/apiserver

sed -i "s/--insecure-bind-address=127.0.0.1/--insecure-bind-address=0.0.0.0/g" /etc/kubernetes/apiserver

sed -i "s/--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota/--admission_control=NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota/g" /etc/kubernetes/apiserver



sed -i "s/--hostname-override=127.0.0.1/--hostname-override=10.135.163.237/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/kubelet


sed -i "s/--address=127.0.0.1/--address=0.0.0.0/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/config

sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/sysconfig/flanneld
0

Start the service 


sed -i "s/localhost:2379/10.135.163.237:2379/g" /etc/etcd/etcd.conf

sed -i "s/localhost:2380/10.135.163.237:2380/g" /etc/etcd/etcd.conf

sed -i "s/10.135.163.237:2379/10.135.163.237:2379,http:\/\/127.0.0.1:2379/g" /etc/etcd/etcd.conf


sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/kubernetes/apiserver

sed -i "s/--insecure-bind-address=127.0.0.1/--insecure-bind-address=0.0.0.0/g" /etc/kubernetes/apiserver

sed -i "s/--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota/--admission_control=NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota/g" /etc/kubernetes/apiserver



sed -i "s/--hostname-override=127.0.0.1/--hostname-override=10.135.163.237/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/kubelet


sed -i "s/--address=127.0.0.1/--address=0.0.0.0/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/config

sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/sysconfig/flanneld
1

View the nodes on the primary server 


sed -i "s/localhost:2379/10.135.163.237:2379/g" /etc/etcd/etcd.conf

sed -i "s/localhost:2380/10.135.163.237:2380/g" /etc/etcd/etcd.conf

sed -i "s/10.135.163.237:2379/10.135.163.237:2379,http:\/\/127.0.0.1:2379/g" /etc/etcd/etcd.conf


sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/kubernetes/apiserver

sed -i "s/--insecure-bind-address=127.0.0.1/--insecure-bind-address=0.0.0.0/g" /etc/kubernetes/apiserver

sed -i "s/--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota/--admission_control=NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota/g" /etc/kubernetes/apiserver



sed -i "s/--hostname-override=127.0.0.1/--hostname-override=10.135.163.237/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/kubelet


sed -i "s/--address=127.0.0.1/--address=0.0.0.0/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/config

sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/sysconfig/flanneld
2

Restart the service (rejoin the cluster) 


systemctl restart kube-apiserver.service

Remove nodes 


sed -i "s/localhost:2379/10.135.163.237:2379/g" /etc/etcd/etcd.conf

sed -i "s/localhost:2380/10.135.163.237:2380/g" /etc/etcd/etcd.conf

sed -i "s/10.135.163.237:2379/10.135.163.237:2379,http:\/\/127.0.0.1:2379/g" /etc/etcd/etcd.conf


sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/kubernetes/apiserver

sed -i "s/--insecure-bind-address=127.0.0.1/--insecure-bind-address=0.0.0.0/g" /etc/kubernetes/apiserver

sed -i "s/--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota/--admission_control=NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota/g" /etc/kubernetes/apiserver



sed -i "s/--hostname-override=127.0.0.1/--hostname-override=10.135.163.237/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/kubelet


sed -i "s/--address=127.0.0.1/--address=0.0.0.0/g" /etc/kubernetes/kubelet


sed -i "s/127.0.0.1:8080/10.135.163.237:8080/g" /etc/kubernetes/config

sed -i "s/127.0.0.1:2379/10.135.163.237:2379/g" /etc/sysconfig/flanneld
4

conclusion

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