记一次用kubeadm安装k8s

安装配置

1. 系统：centos7
2. k8s 版本：1.16.2 （1.24之后用的是contained，这里安装方式会存在问题）
3. 配置：一个master节点 两个node节点

前置配置

1. 设置主机名

   hostnamectl set-hostname k8s-master
   hostnamectl set-hostname k8s-slave1
   hostnamectl set-hostname k8s-slave2
   

2. 修改host

   cat << EOF >> /etc/hosts
   10.211.55.21 k8s-master
   10.211.55.22 k8s-slave1
   10.211.55.23 k8s-slave2
   EOF
   

安装docker(所有节点都需操作)

1. 关闭防火墙

   systemctl stop firewalld.service 
   systemctl disable firewalld.service
   

2. 关闭交换空间

   swapoff -a
   sed -i 's/.*swap.*/#&/' /etc/fstab
   

3. 关闭selinux

   setenforce 0
   sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
   

4. 修改内核数

   # 修改内核参数
   cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
   net.bridge.bridge-nf-call-iptables  = 1
   net.bridge.bridge-nf-call-ip6tables = 1
   net.ipv4.ip_forward                 = 1
   EOF
   

5. 设置yum源

   curl -o /etc/yum.repos.d/Centos-7.repo http://mirrors.aliyun.com/repo/Centos-7.repo
   curl -o /etc/yum.repos.d/docker-ce.repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
   
   cat <<EOF > /etc/yum.repos.d/kubernetes.repo
   [kubernetes]
   name=Kubernetes
   baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
   # 是否开启本仓库
   enabled=1
   # 是否检查 gpg 签名文件
   gpgcheck=0
   # 是否检查 gpg 签名文件
   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
   

6. 设置yum缓存 yum clean all && yum makecache

   yum clean all && yum makecache
   

7. 安装docker-ce

   yum install docker-ce
   

8. 设置docker源加速

   sudo mkdir -p /etc/docker
   sudo tee /etc/docker/daemon.json <<-'EOF'
   {
     "registry-mirrors": [
       "https://dockerproxy.com",
       "https://hub-mirror.c.163.com",
       "https://mirror.baidubce.com",
       "https://ccr.ccs.tencentyun.com"
     ],
     "insecure-registries" : ["http://10.211.55.100:5000"]
   }
   EOF
   

9. 重启docker

   systemctl daemon-reload && systemctl restart docker
   

10. 安装kubeadm kubelet kubectl

    yum install -y kubelet-1.16.2 kubeadm-1.16.2 kubectl-1.16.2 -- disableexclues=kubernetes
    
    systemctl enable kubelet
    

安装kubeadm（只在master操作）

1. 初始化

   kubeadm config print init-defaults > kubeadm.yaml 
   

2. 修改配置

   apiVersion: kubeadm.k8s.io/v1beta2
   bootstrapTokens:
   - groups:
     - system:bootstrappers:kubeadm:default-node-token
     token: abcdef.0123456789abcdef
     ttl: 24h0m0s
     usages:
     - signing
     - authentication
   kind: InitConfiguration
   localAPIEndpoint:
     # 修改主机地址 为master的ip
     advertiseAddress: 10.211.55.21
     bindPort: 6443
   nodeRegistration:
     criSocket: /var/run/dockershim.sock
     name: k8s-master
     taints:
     - effect: NoSchedule
       key: node-role.kubernetes.io/master
   ---
   apiServer:
     timeoutForControlPlane: 4m0s
   apiVersion: kubeadm.k8s.io/v1beta2
   certificatesDir: /etc/kubernetes/pki
   clusterName: kubernetes
   controllerManager: {}
   dns:
     type: CoreDNS
   etcd:
     local:
       dataDir: /var/lib/etcd
   # 修改镜像地址
   imageRepository: registry.aliyuncs.com/google_containers
   kind: ClusterConfiguration
   # 修改版本号为install的版本号，前面我们装的事1.16.2
   kubernetesVersion: v1.16.2
   networking:
     dnsDomain: cluster.local
     # 增加pod网络配置
     podSubnet: 10.244.0.0/16
     serviceSubnet: 10.96.0.0/12
   scheduler: {}
   

3. 拉取镜像

   kubeadm config images pull --config kubeadm.yaml
   

4. 初始化

   kubeadm init --config kubeadm.yaml
   

5. 根据提示信息导入环境变量

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

配置网络

1. 获取配置

   wget https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml
   

2. 安装

   kubectl apply -f kube-flannel.yml
   

3. 解决 flannel 无可执行命令问题

   # slave可能也会有这个问题，需要同样处理
   https://github.com/containernetworking/plugins/releases/tag/v0.8.6
   wget https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz
   tar axvf ./cni-plugins-linux-amd64-v0.8.6.tgz  -C /opt/cni/bin/
   

测试nginx

1. 增加配置

   cat << EOF >> nginx.yaml 
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx-deployment
     labels:
       app: nginx
   spec:
     replicas: 2
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - name: nginx
           image: nginx:1.23.2
           ports:
           - containerPort: 80
   EOF
   

2. 执行nginx配置

   kubectl apply -f nginx.yaml
   

操作命令记录

# 查看部署node
kubectl get node
# 查看所用namespace
kubectl get pods --all-namespaces
kubectl get pods --all-namespaces -o wide

# 查看node信息
kubectl describe node k8s-slave1

# 查看pod信息
kubectl -n ns describe pod podName

# 查看kubelet状态 
journalctl -f -u kubelet.service

kubectl create -f nginx.yaml
kubectl apply -f nginx.yaml
kubectl delete -f nginx.yaml