Kubernetes集群搭建 ver1.20.5
阅读原文时间:2022年01月01日阅读:9

Kubernetes是一个可移植的、可扩展的容器集群管理系统开源平台,用于管理容器化的工作负载和服务,可促进声明式配置和自动化,适用于快速交付和频繁变更的场景

kubernetes的特点

可移植: 支持公有云,私有云,混合云,多重云(multi-cloud)

可扩展: 模块化, 插件化, 可挂载, 可组合

自动化: 自动部署,自动重启,自动复制,自动伸缩/扩展

  1. kubeadm方式部署,部署简单,开发环境
  2. ansible部署,方便做后期节点的添加与维护
  3. 二进制方式部署,复杂度高,但可以高度自定义参数
  1. 最小化基础系统(此处为Centos 7.9.2009)
  2. 关闭防火墙 selinux和swap
  3. 更新软件源
  4. 时间同步
  5. 各节点安装docker
  • docker要使用兼容的版本,查看kubernetes release changelog说明
  • kubernetes-1.20 CRI 移除docker支持,改用docker shim,此处CRI部署使用docker-ce-3:19.03.15-3.el7

https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.20.md

Deprecation
Docker support in the kubelet is now deprecated and will be removed in a future release. The kubelet uses a module called "dockershim" which implements CRI support for Docker and it has seen maintenance issues in the Kubernetes community. We encourage you to evaluate moving to a container runtime that is a full-fledged implementation of CRI (v1alpha1 or v1 compliant) as they become available. (#94624, @dims) [SIG Node]
Kubectl: deprecate --delete-local-data (#95076, @dougsland) [SIG CLI, Cloud Provider and Scalability]

1.1 基础初始化

sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
setenforce 0
systemctl disable --now firewalld
swapoff -a
sed -i.bak /swap/d /etc/fstab
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo\
yum -y install vim curl dnf
timedatectl set-ntp true
# 增加内核配置
cat <<EOF > /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system
vim /etc/hosts  # 节点hosts本地解析

# 配置阿里云kubernetes镜像
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[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

# dnf list  kubelet --showduplicates
# 由于官网未开放同步方式, 可能会有索引gpg检查失败的情况, 这时请用 yum install -y --nogpgcheck kubelet kubeadm kubectl 安装

1.2 安装docker

wget -O /etc/yum.repos.d/docker-ce.repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# VERSION=3:20.10.5-3.el7
VERSION=3:19.03.15-3.el7
dnf -y install docker-ce-${VERSION}
systemctl enable --now docker
sudo mkdir -p /etc/docker
# 使用推荐的systemd驱动程序  https://kubernetes.io/docs/setup/production-environment/container-runtimes/
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://0nth4654.mirror.aliyuncs.com"],
  "exec-opts":["native.cgroupdriver=systemd"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker
systemctl enable docker

$ vim /usr/lib/systemd/system/docker.service
$ 使用推荐的systemd驱动程序
$ ExecStart=/usr/bin/dockerd --exec-opt native.cgroupdriver=systemd

2.1 镜像加速配置

#kubeadm config images list --kubernetes-version v1.20.5
k8s.gcr.io/kube-apiserver:v1.20.5
k8s.gcr.io/kube-controller-manager:v1.20.5
k8s.gcr.io/kube-scheduler:v1.20.5
k8s.gcr.io/kube-proxy:v1.20.5
k8s.gcr.io/pause:3.2
k8s.gcr.io/etcd:3.4.13-0
k8s.gcr.io/coredns:1.7.0

docker pull  registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.20.5
...

docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.20.5 harbor.alp.local/kubernetes-basic/kube-apiserver:v1.20.5
...

2.2 高可用master可配置

在所有的master节点安装指定版本的kubeadm、kubelet、kubectl、docker

在master和node节点安装kubeadm、kubelet、kubectl、docker等软件

# dnf list kubeadm --showduplicates
version=1.20.5 && echo $version
dnf install kubeadm-$version kubelet-$version kubectl-$version
systemctl enable --now kubelet && systemctl status kubelet

在所有node节点安装指定版本的kubeadm、kubelet、docker

version=1.20.5 && echo $version
dnf install kubeadm-$version kubelet-$version
systemctl enable --now kubelet

所有节点都需要安装kubeadm on ubuntu

# for master
apt-cache madsion kubeadm=1.17.2-00 kubectl-1.17.2-00 kubelet=1.17.2-00

# for node
apt install  kubeadm=1.17.2-00 kubelet=1.17.2-00

https://kubernetes.io/zh/docs/setup/production-environment/tools/kubeadm/install-kubeadm/

master节点中任意一台进行初始化,且只需要初始化一次

# kubeadm init -h
# kubeadm config images list --kubernetes-version v1.20.5   # 可提前下载镜像,防止初始化失败
# https://kubernetes.io/zh/docs/reference/setup-tools/kubeadm/kubeadm-init/

kubeadm init \
--apiserver-advertise-address=192.168.1.113 \
--apiserver-bind-port=6443 \
--control-plane-endpoint=192.168.1.113 \
--ignore-preflight-errors=swap \
--service-dns-domain=alp.domain \
--image-repository=registry.cn-hangzhou.aliyuncs.com/google_containers \
--kubernetes-version=1.20.5 \
--pod-network-cidr=10.0.0.0/16 \
--service-cidr=172.20.1.0/20

#################################################
[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

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/

You can now join any number of control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join 192.168.1.113:6443 --token 0ej3dg.1msgev7hznukc183 \
    --discovery-token-ca-cert-hash sha256:7c901a6b1ae135e2ce1012265d9bd3887e128b7d35e147a29ecdeb5e6ca01568 \
    --control-plane

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

kubeadm join 192.168.1.113:6443 --token 0ej3dg.1msgev7hznukc183 \
    --discovery-token-ca-cert-hash sha256:7c901a6b1ae135e2ce1012265d9bd3887e128b7d35e147a29ecdeb5e6ca01568

5.1基于文件初始化master节点

kubeadm config print init-defaults > kubeadm-init.yml  # 输出默认初始化配置
vim kubeadm-init.yml
# bootstrapTokens时间
# 监听地址 advertiseAddress
# kubernetesVersion
# dnsDomain
# + podSubnet
# serviceSubnet
# imageRepository
# + controlPlanEndpoint   # vip地址 172.16.3.248:6443
# 40 line

kubeadm init --config kubeadm-init.yml

5.2 将其他master主机加入集群(扩容master )

kubeadm init phase upload-certs --upload-certs   # 取得key

kubeadm join 192.168.1.113:6443 --token gpduj8.mpejowfe7entffhk \
    --discovery-token-ca-cert-hash sha256:1a56f5c63583097f19842b56195648c4df233448db80905c4c808f9f28821d82 \
    --control-plane --certificate-key ${key}

6.1 安装flannel网络插件

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
修改默认的pod-network-cidr为初始化设置的(默认配置为10.244.0.0)  

kubectl apply -f kube-flannel.yml

6.2 查看集群状态

export KUBECONFIG=/etc/kubernetes/admin.conf

[0 root@master1 /root] #kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.5", GitCommit:"6b1d87acf3c8253c123756b9e61dac642678305f", GitTreeState:"clean", BuildDate:"2021-03-18T01:08:27Z", GoVersion:"go1.15.8", Compiler:"gc", Platform:"linux/amd64"}
[0 root@master /root] #kubectl get nodes -A
NAME     STATUS     ROLES                  AGE     VERSION
master   NotReady   control-plane,master   7m17s   v1.20.5
[0 root@master1 /root] #kubectl get pods -A
NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE
kube-system   coredns-54d67798b7-6sfsj         0/1     Pending   0          7m6s
kube-system   coredns-54d67798b7-v2lh6         0/1     Pending   0          7m6s
kube-system   etcd-master                      1/1     Running   0          7m13s
kube-system   kube-apiserver-master            1/1     Running   0          7m13s
kube-system   kube-controller-manager-master   1/1     Running   0          7m13s
kube-system   kube-proxy-6zfdd                 1/1     Running   0          7m6s
kube-system   kube-scheduler-master            1/1     Running   0          7m13s

6.3 使得单master节点状态可用

kubectl taint node master node-role.kubernetes.io/master=:NoSchedule    #设置master不可调度
kubectl taint node master node-role.kubernetes.io/master-                 # 设置master可调度
kubectl describe node master  | grep Taints                     # 查看污点标签

6.4 增加master节点

6.4.1 拷贝证书方式

# 1. 从已kubeadm init的节点拷贝证书
scp /etc/kubernetes/pki/ca.* master-2:/etc/kubernetes/pki/
scp /etc/kubernetes/pki/sa.* master-2:/etc/kubernetes/pki/
scp /etc/kubernetes/pki/front-proxy-ca.* master-2:/etc/kubernetes/pki/
scp /etc/kubernetes/pki/etcd/ca.* master-2:/etc/kubernetes/pki/etcd/

# 2. 新master进行初始化
kubeadm join 192.168.1.113:6443 --token 0ej3dg.1msgev7hznukc183 \
  --discovery-token-ca-cert-hash sha256:7c901a6b1ae135e2ce1012265d9bd3887e128b7d35e147a29ecdeb5e6ca01568 \
  --control-plane

6.4.2 生成证书方式

# 1. 当前 maste 生成证书用于添加新控制节点
kubeadm init phase upload-certs --upload-certs

# 2. 新master进行初始化
kubeadm join 192.168.1.113:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:c555fd7cdf1f08d1b4aab959417bb620010e3376c6be406d8a36ddc1fdd233eb \
    --control-plane \
    --certificate-key 6ff68e4e7c0255073a9f0a9d96b76fc8f4ec4b490dfdaf6a567b4dd95622f012

使用kubeadm将node节点加入k8smaster

kubeadm join 192.168.1.113:6443 --token 0ej3dg.1msgev7hznukc183 \
    --discovery-token-ca-cert-hash sha256:7c901a6b1ae135e2ce1012265d9bd3887e128b7d35e147a29ecdeb5e6ca01568

kubeadm重新生成加入token

# kubeadm token create --print-join-command


# 查看node状态
kubectl get node
kubectl describe node node1

# 验证k8s集群状态
kubectl get cs
NAME STATUS MESSAGE ERROR
controller-manager Healthy ok
scheduler Healthy ok
etcd-0 Healthy {"health":"true"}

# 当前csr证书状态
kubectl get csr
NAME AGE REQUESTOR CONDITION
csr-7bzrk 14m system:bootstrap:0fpghu Approved,Issued
csr-jns87 20m system:node:kubeadm-master1.magedu.net Approved,Issued
csr-vcjdl 14m system:bootstrap:0fpghu Approved,Issued


kubectl create deployment net --image=busybox --replicas=3 -- sleep 36000
# kubectl scale deploy net --replicas=10
kubectl get pod -o wide
kubectl exec -it $(pod_name) --  sh
# ping 其他pod节点和外网测试网络通信

https://github.com/kubernetes/dashboard

https://github.com/kubernetes/dashboard/blob/master/docs/user/access-control/creating-sample-user.md

10.2 配置与安装 dashboard与admin-user

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.2.0/aio/deploy/recommended.yaml -o dashboard-v2.2.0.yml
# 由于官方为localhost访问,此处添加type: NodePort直接代理出来访问dashboard(添加第40行)
# cat -n dashboard-v2.2.0.yml | sed -n 32,45p
    32    kind: Service
    33    apiVersion: v1
    34    metadata:
    35      labels:
    36        k8s-app: kubernetes-dashboard
    37      name: kubernetes-dashboard
    38      namespace: kubernetes-dashboard
    39    spec:
++> 40      type: NodePort
    41      ports:
    42        - port: 443
    43          targetPort: 8443
    44      selector:
    45        k8s-app: kubernetes-dashboard

# cat admin-user.yml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard

# kubectl apply -f dashboard-v2.2.0.yml -f admin-user.yml

10.2 登录dashboard

#- 1. 获取nodeport 为 32241
#kubectl get services -n kubernetes-dashboard
NAME                        TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)         AGE
dashboard-metrics-scraper   ClusterIP   172.16.4.15   <none>        8000/TCP        41m
kubernetes-dashboard        NodePort    172.16.1.0    <none>        443:32241/TCP   41m

#- 2. 获取token
# kubectl get secret -A | grep admin-user
# kubectl describe secret admin-user-token-nzpjj  -n kubernetes-dashboard

# -3. 访问dashboard
https://192.168.1.113:32241

10.3 Kubeconfig登录

制作Kubeconfig文件

10.4 设置token登录会话保持时间

# vim dashboard/kubernetes-dashboard.yaml
&nbsp;&nbsp;&nbsp;image: harbor.alp.local/baseimages/kubernetes-dashboard-amd64:v1.10.1
&nbsp;&nbsp;&nbsp;ports:
&nbsp;&nbsp;&nbsp;- containerPort: 8443
&nbsp;&nbsp;&nbsp;&nbsp;protocol: TCP
&nbsp;&nbsp;&nbsp;args:
&nbsp;&nbsp;&nbsp;&nbsp;- --auto-generate-certificates
&nbsp;&nbsp;&nbsp;&nbsp;- --token-ttl=43200
# kubectl apply -f .

https://v1-20.docs.kubernetes.io/zh/docs/setup/release/version-skew-policy/

11.1 升级kubeadm为指定版本

dnf install kubeadm=1.20.4

11.2 升级master

kubeadm upgrade plan   # 查看变化
kubeadm upgrade apply v1.20.4   # 开始升级
dnf install kubelet=1.20.4 kubectl=1.20.4 kubeadm=1.20.4

11.2 升级node

kubeadm upgrade node --kubelet-version 1.20.4   #升级各 node 节点配置文件
dnf install kubelet=1.20.4 kubeadm=1.20.4  #升级 kubelet 二进制包


kubeadm reset   # 重置节点,不可恢复
kubeadm token --help   # token管理
kubectl taint node master node-role.kubernetes.io/master-  #设置master节点可调度

# node节点重建操作
# kubectl drain node01 --delete-local-data --force --ignore-daemonsets
                  #清空节点(若节点已经NotReady了,则drain命令会卡住无法完成)
kubectl delete node node01    # 删除node01节点
kubectl uncordon node01       # 恢复node01节点调度

# 初始化 Control-plane/Master 节点
kubeadm init \
    --apiserver-advertise-address 0.0.0.0 \
    # API 服务器所公布的其正在监听的 IP 地址,指定“0.0.0.0”以使用默认网络接口的地址
    # 切记只可以是内网IP,不能是外网IP,如果有多网卡,可以使用此选项指定某个网卡
    --apiserver-bind-port 6443 \
    # API 服务器绑定的端口,默认 6443
    --cert-dir /etc/kubernetes/pki \
    # 保存和存储证书的路径,默认值:"/etc/kubernetes/pki"
    --control-plane-endpoint kuber4s.api \
    # 为控制平面指定一个稳定的 IP 地址或 DNS 名称,
    # 这里指定的 kuber4s.api 已经在 /etc/hosts 配置解析为本机IP
    --image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
    # 选择用于拉取Control-plane的镜像的容器仓库,默认值:"k8s.gcr.io"
    # 因 Google被墙,这里选择国内仓库
    --kubernetes-version 1.17.3 \
    # 为Control-plane选择一个特定的 Kubernetes 版本, 默认值:"stable-1"
    --node-name master01 \
    #  指定节点的名称,不指定的话为主机hostname,默认可以不指定
    --pod-network-cidr 10.10.0.0/16 \
    # 指定pod的IP地址范围
    --service-cidr 10.20.0.0/16 \
    # 指定Service的VIP地址范围
    --service-dns-domain cluster.local \
    # 为Service另外指定域名,默认"cluster.local"
    --upload-certs
    # 将 Control-plane 证书上传到 kubeadm-certs Secret

- 手把手从零搭建与运营生产级的 Kubernetes 集群与 KubeSphere

- kubectl cmd

- kubernetes技能图谱

- kubeadm-init.yml

apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 36h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 192.168.1.113
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: master
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
# controlPlaneEndpoint: 192.168.1.113:6443
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.20.5
networking:
  dnsDomain: alpine.local
  podSubnet: 10.0.0.0/16
  serviceSubnet: 172.16.0.0/20
scheduler: {}