Kubernetes 安裝手冊（Ubuntu非高可用版）

阿新 • • 發佈：2021-08-13

安裝前準備工作
部署kubernetes

安裝前準備工作

1.設定hosts解析

操作節點：所有節點（k8s-master）均需執行

修改hostname

# 在master節點
$ hostnamectl set-hostname k8s-master #設定master節點的hostname

# slave1節點
$ hostnamectl set-hostname k8s-worker-node1

# slave2節點
$ hostnamectl set-hostname k8s-worker-node2

2.調整系統配置

操作節點：所有的master和slave節點（k8s-master,k8s-slave）需要執行

設定iptables

$ iptables -P FORWARD ACCEPT
$ /etc/init.d/ufw stop
$ ufw disable

*關閉swap

swapoff -a
# 防止開機自動掛載 swap 分割槽
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

修改核心引數

cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward=1
vm.max_map_count=262144
EOF
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf

設定apt源

$ apt-get update && apt-get install -y apt-transport-https ca-certificates software-properties-common 
$ curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add - 
$ curl -fsSL https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu/gpg | sudo apt-key add 
$ add-apt-repository "deb [arch=amd64] https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu $(lsb_release -cs) stable"
$ add-apt-repository "deb [arch=amd64] https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main"

$ apt-get update   
#若上步出現NO_PUBLICKEY問題，參考https://www.cnblogs.com/jiangzuo/p/13667011.html

3.安裝docker

操作節點：所有節點

$ apt-get install docker-ce=5:20.10.8~3-0~ubuntu-bionic
## 啟動docker
$ systemctl enable docker && systemctl start docker

部署kubernetes

1.安裝 kubeadm,kubelet和kubectl

操作節點：所有的master和slave節點(k8s-master,k8s-slave) 需要執行

$ apt-get install kubelet=1.21.1-00 kubectl=1.21.1-00 kubeadm=1.21.1-00
## 檢視kubeadm 版本
$ kubeadm version
## 設定kubelet開機啟動
$ systemctl enable kubelet

2.初始化配置檔案

操作節點：只在master節點（k8s-master）執行

$ kubeadm config print init-defaults > kubeadm.yaml
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 192.168.136.138    # 修改為master節點ip
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: node     # 刪掉此行，刪掉此行，刪掉此行
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers    # 修改此處映象repo
kind: ClusterConfiguration
kubernetesVersion: 1.21.0
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16		# 新增此行
  serviceSubnet: 10.96.0.0/12
scheduler: {}

3.提前下載映象

操作節點：只在master節點（k8s-master）執行

  # 提前下載映象到本地
$ kubeadm config images pull --config kubeadm.yaml
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-apiserver:v1.21.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-controller-manager:v1.21.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-scheduler:v1.21.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-proxy:v1.21.0
[config/images] Pulled registry.aliyuncs.com/google_containers/pause:3.4.1
[config/images] Pulled registry.aliyuncs.com/google_containers/etcd:3.4.13-0
failed to pull image "registry.aliyuncs.com/google_containers/coredns/coredns:v1.8.0": output: Error response from daemon: pull access denied for registry.aliyuncs.com/google_containers/coredns/coredns, repository does not exist or may require 'docker login': denied: requested access to the resource is denied
, error: exit status 1
To see the stack trace of this error execute with --v=5 or higher

提示找不到coredns的映象，我們可以通過如下方式解決：

$ docker pull coredns/coredns:1.8.0
$ docker tag coredns/coredns:1.8.0 registry.aliyuncs.com/google_containers/coredns/coredns:v1.8.0

4.初始化master節點

操作節點：只在master節點（k8s-master）執行

$ kubeadm init --config kubeadm.yaml

若初始化成功後，最後會提示如下資訊：

...
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 192.168.136.138:6443 --token abcdef.0123456789abcdef \
        --discovery-token-ca-cert-hash sha256:3a7987c9f5007ebac7980e6614281ee0e064c760c8db012471f9f662289cc9ce

接下來按照上述提示資訊操作，配置kubectl客戶端的認證

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

⚠️注意：此時使用 kubectl get nodes檢視節點應該處於notReady狀態，因為還未配置網路外掛

若執行初始化過程中出錯，根據錯誤資訊調整後，執行kubeadm reset後再次執行init操作即可

5.新增slave節點到叢集中

操作節點：所有的slave節點（k8s-slave）需要執行
在每臺slave節點，執行如下命令，該命令是在kubeadm init成功後提示資訊中打印出來的，需要替換成實際init後打印出的命令。

kubeadm join 192.168.136.135:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:1c4305f032f4bf534f628c32f5039084f4b103c922ff71b12a5f0f98d1ca9a4f

6.安裝calico外掛

操作節點：只在master節點（k8s-master）執行

安裝operator

$ kubectl create -f https://docs.projectcalico.org/manifests/tigera-operator.yaml

等待operator pod安裝啟動完成

$ kubectl -n tigera-operator get po
NAME                               READY   STATUS    RESTARTS   AGE
tigera-operator-698876cbb5-kfpb2   1/1     Running   0          38m

映象拉取比較慢，可以手動去節點docker pull拉取

編輯calico配置

$ vim custom-resources.yaml
apiVersion: operator.tigera.io/v1
kind: Installation
metadata:
  name: default
spec:
  # Configures Calico networking.
  calicoNetwork:
    # Note: The ipPools section cannot be modified post-install.
    ipPools:
    - blockSize: 26
      cidr: 10.244.0.0/16        #修改和pod cidr一致
      encapsulation: VXLANCrossSubnet
      natOutgoing: Enabled
      nodeSelector: all()

---

# This section configures the Calico API server.
# For more information, see: https://docs.projectcalico.org/v3.20/reference/installation/api#operator.tigera.io/v1.APIServer
apiVersion: operator.tigera.io/v1
kind: APIServer
metadata:
  name: default
spec: {}

建立calico配置

$ kubectl apply -f custom-resources.yaml

等待operator自動建立calico的pod

# operator會自動建立calico-apiserver和calico-system兩個名稱空間以及必要的pod，等待pod啟動完成即可
$ kubectl get ns
NAME               STATUS   AGE
calico-apiserver   Active   13m
calico-system      Active   19m

$ kubectl -n calico-apiserver get po
NAME                                READY   STATUS    RESTARTS   AGE
calico-apiserver-554fbf9554-b6kzv   1/1     Running   0          13m

$ kubectl -n calico-system get po
NAME                                       READY   STATUS    RESTARTS   AGE
calico-kube-controllers-868b656ff4-hn6qv   1/1     Running   0          20m
calico-node-qqrp9                          1/1     Running   0          20m
calico-node-r45z2                          1/1     Running   0          20m
calico-typha-5b64cf4b48-vws5j              1/1     Running   0          20m
calico-typha-5b64cf4b48-w6wqf              1/1     Running   0          20m

7.驗證叢集

操作節點：在master節點（k8s-master）執行

$ kubectl get nodes  #觀察叢集節點是否全部Ready

建立測試nginx服務

$ kubectl run  test-nginx --image=nginx:alpine

檢視pod是否建立成功，並訪問pod ip測試是否可用

$ kubectl get po -o wide
NAME                          READY   STATUS    RESTARTS   AGE   IP           NODE         NOMINATED NODE   READINESS GATES
test-nginx-5bd8859b98-5nnnw   1/1     Running   0          9s    10.244.1.2   k8s-slave1   <none>           <none>
$ curl 10.244.1.2
...
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

8.清理環境

如果你的叢集安裝過程中遇到了其他問題，我們可以使用下面的命令來進行重置：

# 在全部叢集節點執行
kubeadm reset
ifconfig cni0 down && ip link delete cni0
ifconfig flannel.1 down && ip link delete flannel.1
rm -rf /run/flannel/subnet.env
rm -rf /var/lib/cni/
mv /etc/kubernetes/ /tmp
mv /var/lib/etcd /tmp
mv ~/.kube /tmp
iptables -F
iptables -t nat -F
ipvsadm -C
ip link del kube-ipvs0
ip link del dummy0