第十章 kubeadm工具安装kubernetes1.21.2

kubeadm 是官方社区推出的一个用于快速部署 kubernetes 集群的工具，这个工具能通过两条指令完成一个 kubernetes 集群的部署：
kube-dns与kubeadm的使用从v1.18开始就不推荐使用，并在v1.21中删除。

第一,创建一个 Master 节点	kubeadm init
第二,将 Node 节点加入到当前集群中 $ kubeadm join <Master 节点的 IP 和端口 >

一、部署系统版本

软件	版本
CentOS	CentOS Linux release 7.9.1908 (Core)
Docker	20.10.10
Kubernetes	v1.21.2
Flannel	V0.13.1
Kernel-lm	kernel-lt-4.4.245-1.el7.elrepo.x86_64.rpm
Kernel-lm-devel	kernel-lt-devel-4.4.245-1.el7.elrepo.x86_64.rpm

二、节点规划

Hostname	Outer-IP	Inner-IP	内核版本
Kubernetes-master-001	192.168.13.100	172.16.1.100	5.4.145-1.el7.elrepo.x86_64
Kubernetes-node-001	192.168.13.101	172.16.1.101	5.4.145-1.el7.elrepo.x86_64
Kubernetes-node-002	192.168.13.102	172.16.1.102	5.4.145-1.el7.elrepo.x86_64

#1.在所有节点上安装 Docker 和 kubeadm

#2.部署 Kubernetes Master

#3.部署容器网络插件

#4.部署 Kubernetes Node，将节点加入 Kubernetes 集群中

#5.部署 Dashboard Web 页面，可视化查看 Kubernetes 资源

三、系统初始化（所有节点）

1.添加host解析

#1.修改主机名
[root@ip-172-16-1-100 ~]# hostnamectl set-hostname Kubernetes-master-001
[root@ip-172-16-1-101 ~]# hostnamectl set-hostname Kubernetes-node-001
[root@ip-172-16-1-102 ~]# hostnamectl set-hostname Kubernetes-node-002

#2.Master节点添加hosts解析
[root@kubernetes-master-001 ~]# vim /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.13.100 Kubernetes-master-001 m1
192.168.13.101 Kubernetes-node-001 n1
192.168.13.102 Kubernetes-node-002 n2

#3.分发hosts文件到Node节点
[root@kubernetes-master-001 ~]# scp /etc/hosts root@n1:/etc/hosts
hosts                                                                                             100%  247     2.7KB/s   00:00    

[root@kubernetes-master-001 ~]# scp /etc/hosts root@n2:/etc/hosts
hosts                                                                                             100%  247   182.8KB/s   00:00   

2.关闭防火墙和Selinux

#1.关闭防火墙
[root@kubernetes-master-001 ~]# systemctl disable --now firewalld

#2.关闭Selinux
1）临时关闭
[root@kubernetes-master-001 ~]# setenforce  0

2）永久关闭
[root@kubernetes-master-001 ~]# sed -i 's#enforcing#disabled#g' /etc/selinux/config

3.关闭swap分区

#1.临时关闭
[root@kubernetes-master-001 ~]# swapoff -a

#2.永久关闭
[root@kubernetes-master-001 ~]# sed -i.bak 's/^.*centos-swap/#&/g' /etc/fstab
[root@kubernetes-master-001 ~]# echo 'KUBELET_EXTRA_ARGS="--fail-swap-on=false"' > /etc/sysconfig/kubelet

4.配置国内yum源

默认情况下，CentOS使用的是官方yum源，所以一般情况下在国内使用是非常慢，所以我们可以替换成国内的一些比较成熟的yum源，例如：清华大学镜像源，网易云镜像源等等。
#1.更改yum源
[root@kubernetes-master-001 ~]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
[root@kubernetes-master-001 ~]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
[root@kubernetes-master-001 ~]# curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

#2.刷新缓存
[root@kubernetes-master-001 ~]# yum makecache

#3.禁止自动更新更新内核版本
[root@kubernetes-master-001 ~]# yum update -y --exclud=kernel*

5.更新内核版本

由于Docker运行需要较新的系统内核功能，例如ipvs等等，所以一般情况下，我们需要使用4.0+以上版本的系统内核。
# 内核要求是4.18+，如果是`CentOS 8`则不需要升级内核
#1.导入elrepo的key
[root@kubernetes-master-001 ~]# rpm -import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

#2.安装elrepo的yum源
[root@kubernetes-master-001 ~]# rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm

#3.仓库启用后，列出可用的内核相关包
[root@kubernetes-master-001 ~]# yum --disablerepo="*" --enablerepo="elrepo-kernel" list available

#4.长期维护版本lt为5.4，最新主线稳定版ml为5.14，我们需要安装最新的长期维护版本内核，使用如下命令：(以后这台机器升级内核直接运行这句就可升级为最新维护版本)
[root@k8s-master-001-001 ~]# yum -y --enablerepo=elrepo-kernel install kernel-lt.x86_64 kernel-lt-devel.x86_64

#5.设置启动优先级
[root@kubernetes-master-001 ~]# grub2-set-default  0 && grub2-mkconfig -o /etc/grub2.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.4.158-1.el7.elrepo.x86_64
Found initrd image: /boot/initramfs-5.4.158-1.el7.elrepo.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-957.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-cdbb018d1b2946f5940de9311b06dc86
Found initrd image: /boot/initramfs-0-rescue-cdbb018d1b2946f5940de9311b06dc86.img
done

#6.查看内核版本
[root@kubernetes-master-001 ~]# grubby --default-kernel
/boot/vmlinuz-5.4.158-1.el7.elrepo.x86_64

6.安装ipvs

ipvs是系统内核中的一个模块，其网络转发性能很高。一般情况下，我们首选ipvs。
#1.安装IPVS
[root@kubernetes-master-001 ~]# yum install -y conntrack-tools ipvsadm ipset conntrack libseccomp

#2.加载IPVS模块
cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
ipvs_modules="ip_vs ip_vs_lc ip_vs_wlc ip_vs_rr ip_vs_wrr ip_vs_lblc ip_vs_lblcr ip_vs_dh ip_vs_sh ip_vs_fo ip_vs_nq ip_vs_sed ip_vs_ftp nf_conntrack"
for kernel_module in \${ipvs_modules}; do
  /sbin/modinfo -F filename \${kernel_module} > /dev/null 2>&1
  if [ $? -eq 0 ]; then
    /sbin/modprobe \${kernel_module}
  fi
done
EOF

#3.授权并查看IPVS
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs

7.优化系统内核参数

内核参数优化的主要目的是使其更适合kubernetes的正常运行。
cat > /etc/sysctl.d/k8s.conf << EOF
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
fs.may_detach_mounts = 1
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
fs.file-max=52706963
fs.nr_open=52706963
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp.keepaliv.probes = 3
net.ipv4.tcp_keepalive_intvl = 15
net.ipv4.tcp.max_tw_buckets = 36000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp.max_orphans = 327680
net.ipv4.tcp_orphan_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.ip_conntrack_max = 65536
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.top_timestamps = 0
net.core.somaxconn = 16384
EOF

#查看内核参数
sysctl -p

# 重启
reboot

8.安装基础软件

安装一些基础软件，是为了方便我们的日常使用。
[root@kubernetes-master-001 ~]# yum install wget expect vim net-tools ntp bash-completion ipvsadm ipset jq iptables conntrack sysstat libseccomp -y

四、安装docker

Docker主要是作为k8s管理的常用的容器工具之一。

#1.CentOS7版
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

yum install docker-ce -y
sudo mkdir -p /etc/docker

# 设置加速器
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://8mh75mhz.mirror.aliyuncs.com"]
}
EOF

sudo systemctl daemon-reload ; systemctl restart docker;systemctl enable --now docker.service

#2.CentOS8版
wget https://download.docker.com/linux/centos/7/x86_64/stable/Packages/containerd.io-1.2.13-3.2.el7.x86_64.rpm
yum install containerd.io-1.2.13-3.2.el7.x86_64.rpm -y
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

yum install docker-ce -y
sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://8mh75mhz.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload ; systemctl restart docker;systemctl enable --now docker.service

五、同步集群时间

在集群当中，时间是一个很重要的概念，一旦集群当中某台机器时间跟集群时间不一致，可能会导致集群面临很多问题。所以，在部署集群之前，需要同步集群当中的所有机器的时间。

#1.CentOS7版
yum install ntp -y

ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo 'Asia/Shanghai' > /etc/timezone

ntpdate time2.aliyun.com

# 写入定时任务
#Timing synchronization time
* * * * * /usr/sbin/ntpdate ntp1.aliyun.com &>/dev/null


#2.CentOS8版
rpm -ivh http://mirrors.wlnmp.com/centos/wlnmp-release-centos.noarch.rpm
yum install wntp -y

ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo 'Asia/Shanghai' > /etc/timezone

ntpdate time2.aliyun.com

# 写入定时任务
#Timing synchronization time
* * * * * /usr/sbin/ntpdate ntp1.aliyun.com &>/dev/null

六、安装Kubernetes

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=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

yum makecache

setenforce 0

# 默认安装最新版
yum install -y kubelet kubeadm kubectl 

# 指定版本安装
yum install -y kubelet-1.21.2 
yum install -y kubeadm-1.21.2
yum install -y kubectl-1.21.2

systemctl enable kubelet && systemctl start kubelet

七、初始化master节点

[root@k8s-master-001-001 ~]# kubeadm  init --image-repository=registry.cn-hangzhou.aliyuncs.com/k8sos  --service-cidr=10.96.0.0/12 --pod-network-cidr=10.244.0.0/16 --kubernetes-version=v1.21.2
... ...
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 192.168.13.100:6443 --token vb47mm.6tehbl5sbc5fqcz7 \
	--discovery-token-ca-cert-hash sha256:107d3665d2b689dd124cc60ed41adcbbf215ab28e2af1b6ca03d27c901575a9d 

kubeadm init \
--image-repository=registry.cn-hangzhou.aliyuncs.com/k8sos \   # 指定下载镜像的仓库
--service-cidr=10.96.0.0/12 \   # 指定k8s智能负载均衡器的网段
--pod-network-cidr=10.244.0.0/16 # 指定k8s服务的网段
--kubernetes-version=v1.21.2 \  # 指定安装的k8s版本号

八、配置kubernetes用户信息

[root@kubernetes-master-001 ~]# mkdir -p $HOME/.kube
[root@kubernetes-master-001 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@kubernetes-master-001 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config
[root@kubernetes-master-001 ~]# export KUBECONFIG=/etc/kubernetes/admin.conf

#登录配置文件
[root@kubernetes-master-001 ~]# cd .kube/
[root@kubernetes-master-001 ~/.kube]# ll config 
-rw------- 1 root root 5594 Nov  8 14:11 config
[root@kubernetes-master-001 ~/.kube]# cat config

九、安装集群网络插件

kubernetes需要使用第三方的网络插件来实现kubernetes的网络功能，这样一来，安装网络插件成为必要前提；第三方网络插件有多种，常用的有flanneld、calico和cannel（flanneld+calico），不同的网络组件，都提供基本的网络功能，为各个Node节点提供IP网络等。

#1.方式一：直接安装
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

#2.方式二：编写配置文件安装

1.编写配置文件

[root@kubernetes-master-001 ~]# vim kube-flannel.yaml
---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: psp.flannel.unprivileged
  annotations:
    seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
    seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
    apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
    apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
  privileged: false
  volumes:
  - configMap
  - secret
  - emptyDir
  - hostPath
  allowedHostPaths:
  - pathPrefix: "/etc/cni/net.d"
  - pathPrefix: "/etc/kube-flannel"
  - pathPrefix: "/run/flannel"
  readOnlyRootFilesystem: false
  # Users and groups
  runAsUser:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  fsGroup:
    rule: RunAsAny
  # Privilege Escalation
  allowPrivilegeEscalation: false
  defaultAllowPrivilegeEscalation: false
  # Capabilities
  allowedCapabilities: ['NET_ADMIN', 'NET_RAW']
  defaultAddCapabilities: []
  requiredDropCapabilities: []
  # Host namespaces
  hostPID: false
  hostIPC: false
  hostNetwork: true
  hostPorts:
  - min: 0
    max: 65535
  # SELinux
  seLinux:
    # SELinux is unused in CaaSP
    rule: 'RunAsAny'
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: flannel
rules:
- apiGroups: ['extensions']
  resources: ['podsecuritypolicies']
  verbs: ['use']
  resourceNames: ['psp.flannel.unprivileged']
- apiGroups:
  - ""
  resources:
  - pods
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - nodes
  verbs:
  - list
  - watch
- apiGroups:
  - ""
  resources:
  - nodes/status
  verbs:
  - patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: flannel
  namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: flannel
data:
  cni-conf.json: |
    {
      "name": "cbr0",
      "cniVersion": "0.3.1",
      "plugins": [
        {
          "type": "flannel",
          "delegate": {
            "hairpinMode": true,
            "isDefaultGateway": true
          }
        },
        {
          "type": "portmap",
          "capabilities": {
            "portMappings": true
          }
        }
      ]
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/os
                operator: In
                values:
                - linux
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.13.1-rc1
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.13.1-rc1
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
            add: ["NET_ADMIN", "NET_RAW"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
      - name: run
        hostPath:
          path: /run/flannel
      - name: cni
        hostPath:
          path: /etc/cni/net.d
      - name: flannel-cfg
        configMap:
          name: kube-flannel-cfg

2.查看镜像

[root@kubernetes-master-001 ~]# cat kube-flannel.yaml |grep image

3.替换镜像

[root@kubernetes-master-001 ~]# sed -i 's#quay.io/coreos/flannel#registry.cn-hangzhou.aliyuncs.com/k8sos/flannel#g' kube-flannel.yaml

4.安装flannel

#1.安装flannel
[root@kubernetes-master-001 ~]# kubectl  apply -f kube-flannel.yaml
Warning: policy/v1beta1 PodSecurityPolicy is deprecated in v1.21+, unavailable in v1.25+
podsecuritypolicy.policy/psp.flannel.unprivileged 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

#2.查看flannel运行状态
[root@kubernetes-master-001 ~]# kubectl get pods -n kube-system
NAME                                            READY   STATUS    RESTARTS   AGE
coredns-978bbc4b6-6dpvj                         1/1     Running   0          18m
coredns-978bbc4b6-lgj6g                         1/1     Running   0          18m
etcd-kubernetes-master-001                      1/1     Running   0          18m
kube-apiserver-kubernetes-master-001            1/1     Running   0          18m
kube-controller-manager-kubernetes-master-001   1/1     Running   0          18m
kube-flannel-ds-wcs76                           1/1     Running   0          71s
kube-proxy-hjljv                                1/1     Running   0          18m
kube-scheduler-kubernetes-master-001            1/1     Running   0          18m

十、 增加命令提示

yum install -y bash-completion
source /usr/share/bash-completion/bash_completion
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc

十一、添加从节点(Node节点)

1.Node节点加入集群

[root@kubernetes-node-001 ~]# kubeadm join 192.168.13.100:6443 --token vb47mm.6tehbl5sbc5fqcz7 --discovery-token-ca-cert-hash sha256:107d3665d2b689dd124cc60ed41adcbbf215ab28e2af1b6ca03d27c901575a9d
[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 -o yaml'
[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.

[root@kubernetes-node-002 ~]# kubeadm join 192.168.13.100:6443 --token vb47mm.6tehbl5sbc5fqcz7 --discovery-token-ca-cert-hash sha256:107d3665d2b689dd124cc60ed41adcbbf215ab28e2af1b6ca03d27c901575a9d
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[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.

2.主节点查看集群信息

[root@kubernetes-master-001 ~]# kubectl  get  nodes
NAME                    STATUS   ROLES                  AGE     VERSION
kubernetes-master-001   Ready    control-plane,master   40m     v1.21.2
kubernetes-node-001     Ready    <none>                 6m58s   v1.21.2
kubernetes-node-002     Ready    <none>                 19m     v1.21.2

十二、测试集群

#1.测试一
[root@kubernetes-master-001 ~]# kubectl run test -it --rm --image=busybox:1.28.3
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
/ #

#2.测试二
[root@kubernetes-master-001 ~]# kubectl create deployment nginx --image=nginx
deployment.apps/nginx created
[root@kubernetes-master-001 ~]# kubectl expose deployment nginx --port=80 --type=NodePort
service/nginx exposed
[root@kubernetes-master-001 ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        42m
nginx        NodePort    10.111.239.146   <none>        80:30828/TCP   8s

[root@kubernetes-master-001 ~]# curl 192.168.13.100:30828
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body {  35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<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>