Ubuntu 20.04 部署kubernetes 1.22 集群

由于众所周知的原因（F**K 红X），CentOS8的生命周期就快结束了，系统要转入Ubuntu的怀抱了，不过还好所有的应用都扔到kubernetes上了，迁移的难度大大降低。近期在做Ubuntu的测试，正好把在ubuntu 20.04 LTS 上部署最新的kubernetes记录下来

基础环境：

系统：ubuntu 20.04 LTS

master：172.19.82.170

slave1：172.19.82.192

slave2：172.19.82.160

基础组件：

$ sudo su# apt update && apt upgrade -y && init 6

# apt install -y net-tools lrzsz htop

配置时间并令时间戳立即生效

# timedatectl set-timezone Asia/Shanghai && systemctl restart rsyslog

设置hosts解析：

# hostnamectl set-hostname master && bash

# hostnamectl set-hostname slave1 && bash

# hostnamectl set-hostname slave2 && bash

# cat >> /etc/hosts<< EOF

172.19.82.170 master

172.19.82.192 slave1

172.19.82.160 slave2

EOF

关闭SWAP（过于简单就不写了）

关闭selinux和防火墙 （过于简单就不写了）

修改内核参数：

# cat >> /etc/sysctl.conf << EOF

net.bridge.bridge-nf-call-ip6tables = 1

net.bridge.bridge-nf-call-iptables = 1

net.ipv4.ip_forward = 1

vm.max_map_count = 262144EOF

# modprobe br_netfilter && sysctl -p /etc/sysctl.conf

设置rp_filter的值

kubernetes集群如果使用的是calico网络插件，那么要求下面两个内核参数为0或者1，ubuntu20.04默认是2

# vim /etc/sysctl.d/10-network-security.conf

net.ipv4.conf.default.rp_filter=1

net.ipv4.conf.all.rp_filter=1

# sysctl –system

安装docker-ce
# apt remove docker docker-engine docker.io containerd runc
# apt-get install ca-certificates \curl gnupg lsb-release
# curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
# echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
# apt update
# apt install docker-ce docker-ce-cli containerd.io
# systemctl enable docker
# mkdir /etc/docker/
# vim /etc/docker/daemon.json
{
        "exec-opts":["native.cgroupdriver=systemd"]
}
# systemctl restart docker

安装kubernetes 1.22
# apt install ca-certificates curl software-properties-common apt-transport-https curl
# curl -s https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo apt-key add -
# cat >> /etc/apt/sources.list.d/kubernetes.list < 
     
修改配置文件   # 只在master节点操作
# kubeadm config print init-defaults > kubeadm.yaml
# vim kubeadm.yaml       修改&新增4处
apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 172.19.82.170   # 修改为master节点IP
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  imagePullPolicy: IfNotPresent
  name: node
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns: {}
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers   # 修改为阿里云源站
kind: ClusterConfiguration
kubernetesVersion: 1.22.2       # 修改为正确的版本号，原来是1.22.0
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16     # 新增
  serviceSubnet: 10.96.0.0/12
scheduler: {}
 
     
查看需要的镜像   # 只在master节点操作
# kubeadm config images list --config kubeadm.yaml
registry.aliyuncs.com/google_containers/kube-apiserver:v1.22.2
registry.aliyuncs.com/google_containers/kube-controller-manager:v1.22.2
registry.aliyuncs.com/google_containers/kube-scheduler:v1.22.2
registry.aliyuncs.com/google_containers/kube-proxy:v1.22.2
registry.aliyuncs.com/google_containers/pause:3.5
registry.aliyuncs.com/google_containers/etcd:3.5.0-0
registry.aliyuncs.com/google_containers/coredns:v1.8.4
  
     
拉取镜像
# kubeadm config images pull --config kubeadm.yaml
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-apiserver:v1.22.2
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-controller-manager:v1.22.2
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-scheduler:v1.22.2
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-proxy:v1.22.2
[config/images] Pulled registry.aliyuncs.com/google_containers/pause:3.5
[config/images] Pulled registry.aliyuncs.com/google_containers/etcd:3.5.0-0
[config/images] Pulled registry.aliyuncs.com/google_containers/coredns:v1.8.4
  
    

初始化集群    # 只在master节点操作
# kubeadm init --config kubeadm.yaml
[init] Using Kubernetes version: v1.22.2
[preflight] Running pre-flight checks
        [WARNING Hostname]: hostname "node" could not be reached
        [WARNING Hostname]: hostname "node": lookup node on 127.0.0.53:53: server 
························
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
·····················
# mkdir -p $HOME/.kube
# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
# chown $(id -u):$(id -g) $HOME/.kube/config
# kubectl get nodes
NAME   STATUS     ROLES                  AGE   VERSION
node   NotReady   control-plane,master   34m   v1.22.2

添加slave节点到master集群中   # 在两个slave节点执行
# kubeadm join 172.19.82.170:6443 --token abcdef.0123456789abcdef \
        --discovery-token-ca-cert-hash sha256:7600dfe96c4aed7cf86a4d43c8ab1653b642f0xxxxxxxxxxxxxxxxxxxxx 

# kubectl get nodes   # 在master节点查看
NAME     STATUS     ROLES                  AGE     VERSION
node     NotReady   control-plane,master   39m     v1.22.2
slave1   NotReady                    2m50s   v1.22.2
slave2   NotReady                    113s    v1.22.2

安装flannel插件
# wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
# vim kube-flannel.yml
在下面增加配置，指定具体的网卡，尤其是在多网卡环境，默认是第一块网卡
args:
        - --ip-masq
        - --kube-subnet-mgr
resources:
变为
args:
        - --ip-masq
        - --kube-subnet-mgr
        - --iface=ens3    # 指定具体的网卡
resources:
# kubectl create -f kube-flannel.yml 

# kubectl get nodes
NAME     STATUS   ROLES                  AGE   VERSION
node     Ready    control-plane,master   63m   v1.22.2
slave1   Ready                     26m   v1.22.2
slave2   Ready                     25m   v1.22.2

这样环境就OK了