1. 环境准备

节点信息	master	node
IP	172.28.14.103	172.28.14.104
内存	4G	2G
CPU	2核	2核
系统	CentOS Linux release 7.8.2003 (Core)	CentOS Linux release 7.8.2003 (Core)

• master节点执行

[root@k8smaster ~]# hostnamectl set-hostname k8smaster
[root@k8smaster ~]# systemctl stop firewalld
[root@k8smaster ~]# setenforce 0 
setenforce: SELinux is disabled
[root@k8smaster ~]# cat >> /etc/hosts << EOF
172.28.14.103 k8smaster
172.28.14.104 k8snode
EOF
[root@k8smaster ~]# reboot

• node节点执行

[root@k8snode ~]# hostnamectl set-hostname k8snode
[root@k8snode ~]# systemctl stop firewalld
[root@k8snode ~]# setenforce 0 
setenforce: SELinux is disabled
[root@k8snode ~]# cat >> /etc/hosts << EOF
172.28.14.103 k8smaster
172.28.14.104 k8snode
EOF
[root@k8snode ~]# reboot

2. 所有节点安装Docker/kubeadm/kubelet

2.1. 安装docker

mkdir /etc/yum.repos.d/back
mv /etc/yum.repos.d/* /etc/yum.repos.d/back/
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
wget -O /etc/yum.repos.d/docker-ce.repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo 
yum -y install docker-ce-18.06.1.ce-3.el7
 # 启动docker
systemctl enable docker && systemctl start docker

# 配置镜像加速器
mkdir -p /etc/docker
tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://6ysopw9t.mirror.aliyuncs.com"]
}
EOF
systemctl daemon-reload
systemctl restart docker

2.2 添加阿里云YUM软件源

# 添加阿里云yum源
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

2.3 安装kubeadm，kubelet和kubectl

yum install -y kubelet-1.18.0 kubeadm-1.18.0 kubectl-1.18.0
systemctl enable kubelet

3. 部署Master

master节点执行

[root@k8smaster ~]# kubeadm init \
   --apiserver-advertise-address=172.28.14.103 \
   --image-repository registry.aliyuncs.com/google_containers \
   --kubernetes-version v1.18.0 \
   --service-cidr=10.96.0.0/12 \
   --pod-network-cidr=10.244.0.0/16
W0818 17:24:16.348436   30168 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.18.0
[preflight] Running pre-flight checks
        [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8smaster kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 172.28.14.103]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8smaster localhost] and IPs [172.28.14.103 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8smaster localhost] and IPs [172.28.14.103 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
W0818 17:24:21.735976   30168 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0818 17:24:21.737007   30168 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 20.502769 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.18" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node k8smaster as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node k8smaster as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 7ykjbd.vdoyl2lgcw7gppx2
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

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

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 172.28.14.103:6443 --token 7ykjbd.vdoyl2lgcw7gppx2 \
    --discovery-token-ca-cert-hash sha256:dc1430249616caf7c59fe02028854be9006e6640d5bc203ccf182fb8286bb5f8 

4. 添加Node

node节点执行

[root@k8snode ~]# kubeadm join 172.28.14.103:6443 --token 7ykjbd.vdoyl2lgcw7gppx2     --discovery-token-ca-cert-hash sha256:dc1430249616caf7c59fe02028854be9006e6640d5bc203ccf182fb8286bb5f8 
W0818 17:29:02.171704   13434 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[preflight] Running pre-flight checks
        [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.18" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

5. 部署网络插件

master节点执行

[root@k8smaster ~]# mkdir flannel
[root@k8smaster ~]# cd flannel/
[root@k8smaster flannel]# curl -O https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  4398  100  4398    0     0   5737      0 --:--:-- --:--:-- --:--:--  5734
[root@k8smaster flannel]# ls
kube-flannel.yml
[root@k8smaster flannel]# docker pull quay.io/coreos/flannel:v0.14.0-rc1
v0.14.0-rc1: Pulling from coreos/flannel
801bfaa63ef2: Pull complete 
e4264a7179f6: Pull complete 
bc75ea45ad2e: Pull complete 
7362b3b13577: Pull complete 
fddb5353186c: Pull complete 
071b96dd834b: Pull complete 
37b23f1e6a4f: Pull complete 
Digest: sha256:0394177305e08d560f3cb5f5dcd1ee12575a9fd5ab801471922ff0b8f5863e92
Status: Downloaded newer image for quay.io/coreos/flannel:v0.14.0-rc1
[root@k8smaster flannel]# export KUBECONFIG=/etc/kubernetes/admin.conf
[root@k8smaster flannel]# source /etc/profile
[root@k8smaster flannel]# kubectl apply -f kube-flannel.yml
namespace/kube-flannel created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created

# 等一会Pending才会变成Running
[root@k8smaster flannel]# kubectl get pods -n kube-system
NAME                                READY   STATUS    RESTARTS   AGE
coredns-7ff77c879f-g2qsm            1/1     Running   0          28m
coredns-7ff77c879f-sv7cb            1/1     Running   0          28m
etcd-k8smaster                      1/1     Running   0          29m
kube-apiserver-k8smaster            1/1     Running   0          29m
kube-controller-manager-k8smaster   1/1     Running   0          29m
kube-proxy-jm62r                    1/1     Running   0          24m
kube-proxy-s2dv7                    1/1     Running   0          28m
kube-scheduler-k8smaster            1/1     Running   0          29m

6. 测试

6.1 创建服务

[root@k8smaster ~]# kubectl create deployment nginx --image=nginx
deployment.apps/nginx created
[root@k8smaster ~]# 
[root@k8smaster ~]# kubectl get pods
NAME                    READY   STATUS    RESTARTS   AGE
nginx-f89759699-t8267   1/1     Running   0          44s
[root@k8smaster ~]# 
[root@k8smaster ~]# 
[root@k8smaster ~]# kubectl get pod,svc
NAME                        READY   STATUS    RESTARTS   AGE
pod/nginx-f89759699-t8267   1/1     Running   0          67s

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   2d17h
[root@k8smaster ~]# 
[root@k8smaster ~]# 
[root@k8smaster ~]# kubectl expose deployment nginx --port=80 --type=NodePort
service/nginx exposed
[root@k8smaster ~]# 
[root@k8smaster ~]# 
[root@k8smaster ~]# kubectl get pod,svc
NAME                        READY   STATUS    RESTARTS   AGE
pod/nginx-f89759699-t8267   1/1     Running   0          94s

NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
service/kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP        2d17h
service/nginx        NodePort    10.109.4.150   <none>        80:32238/TCP   3s
[root@k8smaster ~]# 

6.2 测试访问

测试访问结果