Use kubeadm installed K8S

Kubeadm installation

kubeadm is Kubernetes official tool for quick installation Kubernetes cluster, along Kubernetes each version release will be updated simultaneously, some of the practical aspects of the cluster configuration kubeadm have to make adjustments, you can learn to cluster configuration Kubernetes official in experiments kubeadm Some new best practices.

Installation Docker ce

Docker install
each machine needs to be filled

Preparing the Environment

Edit correspondence between hosts

cat <<EOF >>/etc/hosts
192.168.37.61 Smile1
192.168.37.62 Smile2
192.168.37.63 Smile3
EOF

Turn off the firewall

systemctl stop firewalld.service  
systemctl disable firewalld.service

Disable SELINUX

sudo setenforce 0
sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config

Close swap

swapoff -a
sed -i 's/.*swap.*/#&/' /etc/fstab 

Add the following kernel configuration parameters

cat > /etc/sysctl.d/k8s.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

The source yum configuration K8S

cat < /etc/yum.repos.d/kubernetes.repo
[Kubernetes]
name = Kubernetes
baseurl = http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled = 1
gpgcheck = 0
repo_gpgcheck = 0
gpgkey = http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

Installation kubelet, kubeadm, kubectl

yum makecache fast
yum install -y kubelet kubeadm kubectl

Adjust the startup mode

kubelet boot environment variables to be like the docker's drive cgroup-driver

docker info | grep -i cgroup
Cgroup Driver: cgroupfs  --> 运行命令显示

docker's cgroup-driver is cgroupfs, and k8s default systemd
modify docker of cgroup-driver

vim /etc/docker/daemon.json
加入内容 : { "exec-opts": ["native.cgroupdriver=systemd"] }

The final contents of the file

{
"registry-mirrors": [
"https://dockerhub.azk8s.cn",
"https://reg-mirror.qiniu.com"
],
"exec-opts": ["native.cgroupdriver=systemd"]
}

Restart Docker

systemctl restart docker
systemctl status docker

Start kubelet Service

systemctl enable kubelet.service
systemctl start kubelet.service

Configuring Master Node

Be kubernetes cluster initialization

Master node Run:
kubeadm the init = --kubernetes-Version 1.15.0  
--apiserver-advertise-address 192.168.37.61 =  
--image-Repository = gcr.azk8s.cn / google_containers  
--pod-Network-CIDR = 10.244. 0.0 / 16 --token-ttl 0

--kubernetes-version: specify the version number
--apiserver-advertise-address: Specifies the host address
in which image-repository This step is very important, kubeadm default from the official website k8s.grc.io download the required image, domestic inaccessible, requiring Ali cloud or other designated domestic warehouse mirror address.

The segment is defined POD: 10.244.0.0/16,

It will return the following message after successful initialization

//这个返回信息三条命令是配置kubectl工具的命令
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

// 这个返回信息是配置Node节点的命令
kubeadm join 192.168.98.230:6443 --token dexs09.ftjp7y7obq6a3t6n \
      --discovery-token-ca-cert-hash sha256:4aace846f8a6c381902592049591152fd7250b63e500e370a4b64902d202f7f2

Configuration tool kubectl

After a successful return to the initialization run three commands

Network deployment pod

There are many Reference
We chose flannel , several others may be a problem

wget https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml

//在kube-flannel.yml里面默认的镜像下载地址是quay.io，国内无法访问，这里替换所有的quay.io为 quay-mirror.qiniu.com
sed -i "s/quay.io/quay-mirror.qiniu.com/g" kube-flannel.yml

The installation command

kubectl apply -f kube-flannel.yml

View the running status

kubectl get pod --all-namespaces -o wide

Make sure that all of the pod are in the running state

Node node deployment

All of the node cluster node is added to kubernets

//在Node节点上执行(这个命令就是集群初始化之后的返回信息)
kubeadm join 192.168.98.230:6443 --token dexs09.ftjp7y7obq6a3t6n \
          --discovery-token-ca-cert-hash sha256:4aace846f8a6c381902592049591152fd7250b63e500e370a4b64902d202f7f2

Status of each node in the cluster is detected last

kubectl get nodes

View the status of each pod again, to ensure that all state in Runing

kubectl get pod --all-namespaces -o wide

If you have a problem, reconfigure the Master

kubeadm reset

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