kubeadm is a tool for rapid deployment of kubernetes clusters launched by the official community.

1. Installation requirements

Before you start to deploy the Kubernetes cluster machine, you need to meet the following conditions:

• One or more machines, operating system centos7.6-86
• Hardware configuration: 4GB or more RAM, 4 CPU s or more, 30GB or more hard disk
• Network interworking among all machines in the cluster
• Disable swap partition

2. Preparation environment

Turn off firewall:
systemctl stop firewalld
systemctl disable firewalld

Close selinux:
sed -i 's/enforcing/disabled/' /etc/selinux/config 
setenforce 0

Close swap:
swapoff -a $temporary
 Sed - I '/ swap / S / ^ \ (. * \) $/ ා \ 1 / g' / etc / fstab $permanent

Add the corresponding relationship between host name and IP (remember to set the host name):
$ cat >> /etc/hosts<<EOF
9.110.187.120 k8s-master
9.110.187.125 k8s-node1
9.110.187.126 k8s-node2
EOF
 Pass the bridged IPv4 traffic to the iptables chain:
$ cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
$ sysctl --system

3. Install Docker/kubeadm/kubelet on all nodes

Kubernetes default CRI (container runtime) is Docker, so install Docker first.

3.1 installing Docker

$ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
$ yum -y install docker-ce-18.06.1.ce-3.el7
$ systemctl enable docker && systemctl start docker
$ docker --version
Docker version 18.06.1-ce, build e68fc7a
$ yum list docker-ce --showduplicates | sort -r

3.2 add Alibaba cloud YUM software source

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

3.3 installation of kubeadm, kubelet and kubectl

Due to frequent version updates, the version number deployment is specified here:

yum install -y kubelet-1.16.2 kubeadm-1.16.2 kubectl-1.16.2 bash-completion wget
systemctl enable kubelet

4. Deploy Kubernetes Master

Executed at 9.110.187.120 (Master).

$ kubeadm init \
  --apiserver-advertise-address=9.110.187.120 \
  --image-repository registry.aliyuncs.com/google_containers \
  --kubernetes-version v1.16.2 \
  --service-cidr=10.1.0.0/16 \
  --pod-network-cidr=10.244.0.0/16

Because the default pull image address k8s.gcr.io is inaccessible in China, Alibaba cloud image warehouse address is specified here.

Using the kubectl tool:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
$ kubectl get nodes

5. Install Pod network plug-in (CNI)

$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

If the download fails, you can change to this image address: lizhenliang/flannel:v0.11.0-amd64

6. Join Kubernetes Node

Executed at 9.110.187.125/126 (Node).

To add a new node to the cluster, execute the kubeadm join command output at kubeadm init:

$ kubeadm join 9.110.187.120:6443 --token esce21.q6hetwm8si29qxwn \
    --discovery-token-ca-cert-hash sha256:00603a05805807501d7181c3d60b478788408cfe6cedefedb1f97569708be9c5

7. Test kubernetes cluster

Create a pod in the Kubernetes cluster and verify that it works:

kubectl create deployment nginx --image=nginx.1.16
kubectl expose deployment nginx --port=80 --type=NodePort
kubectl get pods -A  -o wide
kubectl describe pod nginx-86c57db685-frwwt

Access address: http://NodeIP:Port

8. Kubernetes V1.16.2 deploy Dashboard V2.0(beta5)

$ wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta5/aio/deploy/recommended.yaml

Modify the contents of the recommended.yaml file (vi recommended.yaml):

---
#Add direct access port
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  type: NodePort #increase
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001 #increase
  selector:
    k8s-app: kubernetes-dashboard

---
#Because many browsers cannot use the automatically generated certificates, we create and comment out the kubernetes dashboard certs object declaration
#apiVersion: v1
#kind: Secret
#metadata:
#  labels:
#    k8s-app: kubernetes-dashboard
#  name: kubernetes-dashboard-certs
#  namespace: kubernetes-dashboard
#type: Opaque

---

Create certificate
mkdir dashboard-certs
cd dashboard-certs/
#Create namespace
kubectl create namespace kubernetes-dashboard    #It will be created automatically in yaml, and can be created independently

# Create key file
openssl genrsa -out dashboard.key 2048

#Certificate request
openssl req -days 36000 -new -out dashboard.csr -key dashboard.key -subj '/CN=dashboard-cert'

#Self signed certificate
openssl x509 -req -in dashboard.csr -signkey dashboard.key -out dashboard.crt

#Create kubernetes dashboard certs object
kubectl create secret generic kubernetes-dashboard-certs --from-file=dashboard.key --from-file=dashboard.crt -n kubernetes-dashboard

Deploy Dashboard

The two images involved can be downloaded first
 Installation
kubectl create -f  ~/recommended.yaml
 #Inspection results
kubectl get pods -A  -o wide

kubectl get service -n kubernetes-dashboard  -o wide

9. Create dashboard administrator

cat >> dashboard-admin.yaml<<EOF
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: dashboard-admin
  namespace: kubernetes-dashboard
EOF

kubectl create -f dashboard-admin.yaml

//Assign permissions to users:
cat >>dashboard-admin-bind-cluster-role.yaml<<EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: dashboard-admin-bind-cluster-role
  labels:
    k8s-app: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: dashboard-admin
  namespace: kubernetes-dashboard
EOF

kubectl create -f dashboard-admin-bind-cluster-role.yaml

Access address: http://NodeIP:30001

Create a service account and bind the default cluster admin administrator cluster role:

$ kubectl create serviceaccount dashboard-admin -n kube-system
$ kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
$ kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')

Log in to the Dashboard with the output token.

10. Install metrics server

Download the image file on Node1/Node2:

docker pull bluersw/metrics-server-amd64:v0.3.6
docker tag bluersw/metrics-server-amd64:v0.3.6 k8s.gcr.io/metrics-server-amd64:v0.3.6  

To perform the installation on the Master:

git clone https://github.com/kubernetes-incubator/metrics-server.git
cd metrics-server/deploy/1.8+/
//Modify metrics-server-deployment.yaml
image: k8s.gcr.io/metrics-server-amd64  #Add the following content under image
        command:
        - /metrics-server
        - --metric-resolution=30s
        - --kubelet-insecure-tls
        - --kubelet-preferred-address-types=InternalIP

//Find runAsNonRoot: true modify to runAsNonRoot: false

kubectl create -f .

//If you can't get the image, you can change image: mirrorgooglecontainers/metrics-server-amd64:v0.3.6