一、准备环境
准备环境：
| 角色 | IP地址 |
| k8s-master | 192.168.56.21 |
| k8s-node01 | 192.168.56.25 |
| k8s-node02 | 192.168.56.26 |
所有节点环境初始化：
关闭防火墙： # systemctl stop firewalld # systemctl disable firewalld 关闭selinux： # sed -i 's/enforcing/disabled/' /etc/selinux/config # setenforce 0 关闭swap： # swapoff -a # sed -ri 's/.*swap.*/#&/' /etc/fstab 按IP分别设置主机名： # hostnamectl set-hostname k8s-master # hostnamectl set-hostname k8s-node01 # hostnamectl set-hostname k8s-node02 仅在master添加hosts： # cat >> /etc/hosts << EOF 192.168.56.21 k8s-master 192.168.56.25 k8s-node01 192.168.56.26 k8s-node02 EOF 将桥接的IPv4流量传递到iptables的链： # cat > /etc/sysctl.d/k8s.conf << EOF net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 EOF # sysctl --system 时间同步： # yum install ntpdate -y # ntpdate time.windows.com
# echo "*/5 * * * * /usr/sbin/ntpdate time.windows.com" >>/var/spool/cron/root
二、在所有节点安装Docker、kubeadm、kubectl、kubelet
2.1 安装docker
# wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo # yum install -y yum-utils device-mapper-persistent-data lvm2 # yum -y install docker-ce # systemctl enable docker && systemctl start docker
2.2 配置阿里云yum源
# 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=0 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
2.3 三个节点安装kubeadmin、kubelet，仅在k8s-master节点上安装kubectl
# yum install -y kubelet-1.19.0 kubeadm-1.19.0 kubectl-1.19.0 # systemctl enable kubelet
三、部署kubernetes master
# kubeadm init \ --apiserver-advertise-address=192.168.56.21 \ --image-repository registry.aliyuncs.com/google_containers \ --kubernetes-version v1.19.0 \ --service-cidr=10.96.0.0/12 \ --pod-network-cidr=10.244.0.0/16 \ --ignore-preflight-errors=all # mkdir -p $HOME/.kube # sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config # sudo chown $(id -u):$(id -g) $HOME/.kube/config
# kubeadm init \
> --apiserver-advertise-address=192.168.56.21 \
> --image-repository registry.aliyuncs.com/google_containers \
> --kubernetes-version v1.19.0 \
> --service-cidr=10.96.0.0/12 \
> --pod-network-cidr=10.244.0.0/16 \
> --ignore-preflight-errors=all
W1005 15:41:47.137328 25574 configset.go:348] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.19.0
[preflight] Running pre-flight checks # 检查环境
[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/
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.9. Latest validated version: 19.03
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki" # 生成k8s和etcd证书
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.56.21]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.56.21 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.56.21 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes" # 生成kubeconfig文件
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env" # 生成kubelet配置文件
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder "/etc/kubernetes/manifests" # 部署管理节点组件，用镜像启动 kubectl get pod -n kube-system
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests" # 部署etcd数据库用镜像启动
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 14.006837 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace # 上传配置文件到k8s中
[kubelet] Creating a ConfigMap "kubelet-config-1.19" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node k8s-master as control-plane by adding the label "node-role.kubernetes.io/master=''" # 给管理节点打一个标签
[mark-control-plane] Marking the node k8s-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule] # 将给管理节点打一个污点
[bootstrap-token] Using token: 46x35t.q5wjyktnsjdeu7gk # 自动为kubelet颁发证书
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS # 部署插件coredns和kube-proxy
[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:
# 接下来需要在master执行的命令
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
# 还需要部署一个网络组件
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:
# 将node节点加入master的命令
kubeadm join 192.168.56.21:6443 --token 46x35t.q5wjyktnsjdeu7gk \
--discovery-token-ca-cert-hash sha256:8d44716e10fc9c16a45cb988cee767f0d4e59f1885e71914cc0ad94ba065aaf4
kubeadm init 的部署过程及日志
四、将node节点加入k8s集群中
]# kubeadm join 192.168.56.21:6443 --token 46x35t.q5wjyktnsjdeu7gk \
> --discovery-token-ca-cert-hash sha256:8d44716e10fc9c16a45cb988cee767f0d4e59f1885e71914cc0ad94ba065aaf4
[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/
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.9. Latest validated version: 19.03
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[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.
默认token有效期为24小时，当过期之后，该token就不可用了。这时就需要重新创建token，操作如下：
[root@k8s-master ~]# kubeadm token create W1005 16:00:31.481430 31411 configset.go:348] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io] i376x3.lw9aepx6ldbzrj5c [root@k8s-master ~]# kubeadm token list TOKEN TTL EXPIRES USAGES DESCRIPTION EXTRA GROUPS i376x3.lw9aepx6ldbzrj5c 23h 2021-10-06T16:00:31+08:00 authentication,signing <none> system:bootstrappers:kubeadm:default-node-token [root@k8s-master ~]# openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //' 8d44716e10fc9c16a45cb988cee767f0d4e59f1885e71914cc0ad94ba065aaf4 [root@k8s-master ~]# kubeadm join 192.168.56.21:6443 --token i376x3.lw9aepx6ldbzrj5c \
--discovery-token-ca-cert-hash sha256:8d44716e10fc9c16a45cb988cee767f0d4e59f1885e71914cc0ad94ba065aaf4
或者直接用命令生成也可以
# kubeadm token create --print-join-command
五、部署网络组件（CNI）
此时查看node节点是NotReady状态
# kubectl get node NAME STATUS ROLES AGE VERSION k8s-master NotReady master 27m v1.19.0 k8s-node01 NotReady <none> 12m v1.19.0 k8s-node02 NotReady <none> 12m v1.19.0
https://kubernetes.io/docs/concepts/cluster-administration/addons/
注意：只需要部署下面其中一个，推荐Calico。
Calico是一个纯三层的数据中心网络方案，Calico支持广泛的平台，包括Kubernetes、OpenStack等。
Calico 在每一个计算节点利用 Linux Kernel 实现了一个高效的虚拟路由器（ vRouter） 来负责数据转发，而每个 vRouter 通过 BGP 协议负责把自己上运行的 workload 的路由信息向整个 Calico 网络内传播。
https://docs.projectcalico.org/getting-started/kubernetes/quickstart
# wget https://docs.projectcalico.org/manifests/calico.yaml --no-check-certificate
下载完后还需要修改里面定义Pod网络（CALICO_IPV4POOL_CIDR），与前面kubeadm init指定的一样
# vim calico.yaml
修改后
当calico的pod都启动成功之后，node节点就会变成ready状态
# kubectl get pod -n kube-system -l k8s-app=calico-node -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES calico-node-4dcl8 1/1 Running 0 12m 192.168.56.25 k8s-node01 <none> <none> calico-node-kjs86 1/1 Running 0 12m 192.168.56.26 k8s-node02 <none> <none> # kubectl get node NAME STATUS ROLES AGE VERSION k8s-master Ready master 39m v1.19.0 k8s-node01 Ready <none> 24m v1.19.0 k8s-node02 Ready <none> 24m v1.19.0