k8s單master叢集部署

鏡像下載下傳、域名解析、時間同步請點選 阿裡雲開源鏡像站

1. 伺服器要求：

• 建議最小硬體配置：2核CPU、2G記憶體、20G硬碟
• 伺服器最好可以通路外網，會有從網上拉取鏡像需求，如果伺服器不能上網，需要提前下載下傳對應鏡像并導入節點

1.1 軟體環境：

1.2 伺服器規劃：

1.3 架構圖：

2. 作業系統初始化配置

# 關閉防火牆
systemctl stop firewalld
systemctl disable firewalld

# 關閉selinux
sed -i '/^SELINUX/s/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 臨時

# 關閉swap
swapoff -a  # 臨時
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久

# 根據規劃設定主機名
hostnamectl set-hostname <hostname>

# 在master添加hosts
cat >> /etc/hosts << EOF
192.168.137.81 k8s-master1
192.168.137.82 k8s-node1
192.168.137.83 k8s-node2
EOF

# 将橋接的IPv4流量傳遞到iptables的鍊
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system  # 生效

# 時間同步
yum install ntpdate -y
ntpdate time.windows.com
           

3. 安裝Docker/kubeadm/kubelet [所有節點]

這裡使用Docker作為容器引擎，也可以換成别的，例如containerd

3.1 安裝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
systemctl enable docker && systemctl start docker
           

3.2 配置鏡像下載下傳加速器

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://v27k018o.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker
           

3.3 添加阿裡雲YUM軟體源

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
           

3.4 安裝kubeadm，kubelet，kubectl

指定需安裝版本号進行部署

yum install -y kubelet-1.20.0 kubeadm-1.20.0 kubectl-1.20.0
systemctl enable kubelet
           

4. 部署Kubernetes Master

在192.168.137.81（Master）執行

kubeadm init \
  --apiserver-advertise-address=192.168.137.81 \
  --image-repository registry.aliyuncs.com/google_containers \
  --kubernetes-version v1.20.0 \
  --service-cidr=10.96.0.0/12 \
  --pod-network-cidr=10.244.0.0/16 \
  --ignore-preflight-errors=all
           

• --apiserver-advertise-address 叢集通告位址
• --image-repository 由于預設拉取鏡像位址k8s.gcr.io國内無法通路，這裡指定阿裡雲鏡像倉庫位址
• --kubernetes-version K8s版本，與上面安裝的一緻
• --service-cidr 叢集内部虛拟網絡，Pod統一通路入口
• --pod-network-cidr Pod網絡，與下面部署的CNI網絡元件yaml中保持一緻

或者使用配置檔案引導：

# cat kubeadm.conf
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.20.0
imageRepository: registry.aliyuncs.com/google_containers 
networking:
  podSubnet: 10.244.0.0/16 
  serviceSubnet: 10.96.0.0/12 

# kubeadm init --config kubeadm.conf --ignore-preflight-errors=all
           

初始化完成後，最後會輸出一個join指令，先記住，下面用。

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

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

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 192.168.137.81:6443 --token tix7ff.pnjcwvl6awyaeh8i \
    --discovery-token-ca-cert-hash sha256:617842ea5040ce5e7f971d387b58693cbfa79261763b68c589fe8d124f1a5154
           

拷貝kubectl使用的連接配接k8s認證檔案到預設路徑：

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

檢視工作節點：

[root@k8s-master ~]# kubectl get nodes
NAME          STATUS     ROLES                  AGE   VERSION
k8s-master1   NotReady   control-plane,master   95s   v1.20.0
           

注：由于網絡插件還沒有部署，還沒有準備就緒 NotReady

5. 加入Kubernetes Node節點

在192.168.137.82/83 (Node) 執行 向叢集添加新節點，執行在kubeadm init輸出的kubeadm join指令：

kubeadm join 192.168.137.81:6443 --token tix7ff.pnjcwvl6awyaeh8i \
    --discovery-token-ca-cert-hash sha256:617842ea5040ce5e7f971d387b58693cbfa79261763b68c589fe8d124f1a5154
           

預設token有效期為24小時，當過期之後，該token就不可用了。這時就需要重新建立token，可以直接使用指令快捷生成：

kubeadm token create --print-join-command
           

參考資料：https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm-join/

6. 部署容器網絡（CNI）

Calico是一個純三層的資料中心網絡方案，是目前Kubernetes主流的網絡方案。 下載下傳YAML：

wget https://docs.projectcalico.org/manifests/calico.yaml
           

下載下傳完後還需要修改裡面定義Pod網絡（CALICO_IPV4POOL_CIDR），與前面kubeadm init的 --pod-network-cidr指定的一樣。 修改完後檔案後，部署：

kubectl apply -f calico.yaml
kubectl get pods -n kube-system
           

等Calico Pod都Running，節點也會準備就緒：

參考資料：https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#pod-network

[root@k8s-master <sub>]# kubectl get pods -n kube-system
NAME                                       READY   STATUS    RESTARTS   AGE
calico-kube-controllers-5f6cfd688c-4hfmv   1/1     Running   0          2m37s
calico-node-8swrp                          1/1     Running   0          2m37s
calico-node-nv96p                          1/1     Running   0          2m37s
calico-node-s2vl6                          1/1     Running   0          2m37s
coredns-7f89b7bc75-7nzm8                   0/1     Running   0          22m
coredns-7f89b7bc75-9c46c                   0/1     Running   0          22m
etcd-k8s-master1                           1/1     Running   0          22m
kube-apiserver-k8s-master1                 1/1     Running   0          22m
kube-controller-manager-k8s-master1        1/1     Running   0          22m
kube-proxy-clc6k                           1/1     Running   0          18m
kube-proxy-dvlvr                           1/1     Running   0          22m
kube-proxy-jr6hm                           1/1     Running   0          18m
kube-scheduler-k8s-master1                 1/1     Running   0          22m
[root@k8s-master </sub>]# kubectl get nodes
NAME          STATUS   ROLES                  AGE   VERSION
k8s-master1   Ready    control-plane,master   23m   v1.20.0
k8s-node1     Ready    <none>                 18m   v1.20.0
k8s-node2     Ready    <none>                 18m   v1.20.0
           

7. 測試kubernetes叢集

在Kubernetes叢集中建立一個pod，驗證是否正常運作：

kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePort
kubectl get pod,svc
           

[root@k8s-master ~]# kubectl get pod,svc
NAME                         READY   STATUS    RESTARTS   AGE
pod/nginx-6799fc88d8-nkzk6   1/1     Running   0          6m51s

NAME                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
service/kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        32m
service/nginx        NodePort    10.108.121.252   <none>        80:30167/TCP   6m2s
           

通路位址：http://NodeIP:Port

8. 部署Dashboard

Dashboard是官方提供的一個UI，可用于基本管理K8s資源。

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.3/aio/deploy/recommended.yaml
           

預設Dashboard隻能叢集内部通路，修改Service為NodePort類型，暴露到外部：

# vi recommended.yaml
...
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001
  selector:
    k8s-app: kubernetes-dashboard
  type: NodePort
...

# kubectl apply -f recommended.yaml
# kubectl get pods -n kubernetes-dashboard
           

通路位址：https://NodeIP:30001 建立service account并綁定預設cluster-admin管理者叢集角色：

# 建立使用者
$ kubectl create serviceaccount dashboard-admin -n kube-system
# 使用者授權
$ kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
# 擷取使用者Token
$ kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
           

使用輸出的token登入Dashboard。

[root@k8s-master ~]# kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
Name:         dashboard-admin-token-cgmld
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: dashboard-admin
              kubernetes.io/service-account.uid: 3208e176-5115-4425-bb67-d45863bc05f7

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1066 bytes
namespace:  11 bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IlBnN2lzMk8zYndPX3ZONnc0cnFnRjhsVnczOTVlNGxXSDl4c1Z0OGtmNDAifQ.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.DY9SLeakUzVUqUHLJjLuaBtv0EOj6l-zsCfmzKTtsiTkaX39bGpLInToKuSpbXHYAmkpCvoZH22ghmOds3LFgvQBCIt6M83rrL83aPzhDjAKtPtPkz9vJGR7K5LnfrB9AX5dVhiU_AkaVIBIFcqTxVlFpl6W1EzTc0uJDM7K8Gr2XnPvRfUMe8WaEWR7tVxMEEhPhP2waEYmcc5uFz5unI_g6lTMYRJnhZCjfqh7lS9NA_8WgmoQnQjxW4cYAsqrdCzbroTEMCslH_pCj-PZNxf7mKVXZwklYL78t8klU_AytuhdaV88iRR3HEuBMYLbfJjy6RLkyt_ORweaXb8npg
           

本文轉自：https://blog.51cto.com/wemux/5354074