一、介绍
# 创建一个 Master 节点
$ kubeadm init
# 将一个 Node 节点加入到当前集群中
$ kubeadm join <Master节点的IP和端口 >
二、kubernetes架构图
三、部署k8s集群
1、基础环境
- 操作系统： CentOS7.x-86_x64
- 硬件配置：2GB或更多RAM，2个CPU或更多CPU，硬盘30GB或更多
- 禁止swap分区
2、服务器规划
| IP | |
|---|---|
| k8s-master | 192.168.56.61 |
| k8s-node1 |
3、系统初始化
#关闭防火墙： systemctl stop firewalld systemctl disable firewalld #关闭selinux： sed -i ‘s/enforcing/disabled/‘ /etc/selinux/config # 永久 setenforce 0 # 临时 #关闭swap： swapoff -a # 临时 #vim /etc/fstab # 永久 #设置主机名： hostnamectl set-hostname <hostname> #在master添加hosts： cat >> /etc/hosts << EOF 192.168.56.61 k8s-master 192.168.56.62 k8s-node1 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 # 生效 #时间同步： yum install ntpdate -y ntpdate time.windows.com
4、
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo yum -y install docker-ce-18.06.1.ce-3.el7 systemctl enable docker && systemctl start docker docker --version cat > /etc/docker/daemon.json << EOF { "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"] } EOF
②
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
③
yum install -y kubelet-1.18.0 kubeadm-1.18.0 kubectl-1.18.0 systemctl enable kubelet
④
Master节点执行
kubeadm init --apiserver-advertise-address=192.168.56.61 --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.18.0 --service-cidr=10.96.0.0/12 --pod-network-cidr=10.244.0.0/16 --ignore-preflight-errors=all
使用配置文件引导
vi kubeadm.conf apiVersion: kubeadm.k8s.io/v1beta2 kind: ClusterConfiguration kubernetesVersion: v1.18.0 imageRepository: registry.aliyuncs.com/google_containers networking: podSubnet: 10.244.0.0/16 serviceSubnet: 10.96.0.0/12 kubeadm init --config kubeadm.conf ignore-preflight-errors=all
⑤配置使用kubectl工具
mkdir -p $HOME/.kube sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config kubectl get nodes
⑥
Then you can join any number of worker nodes by running the following on each as root: kubeadm join 192.168.56.61:6443 --token 94kw30.b1gswshp2grv5vgd --discovery-token-ca-cert-hash sha256:0497a78ea746f2c1f48d67f3dca9d65cb4010868f22f2a0bbefb101d74c6f057
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：
kubeadm token create kubeadm token list openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed ‘s/^.* //‘ 0497a78ea746f2c1f48d67f3dca9d65cb4010868f22f2a0bbefb101d74c6f057 kubeadm join 192.168.56.61:6443 --token 94kw30.b1gswshp2grv5vgd --discovery-token-ca-cert-hash sha256:0497a78ea746f2c1f48d67f3dca9d65cb4010868f22f2a0bbefb101d74c6f057
5、部署
①
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。此外，Calico 项目还实现了 Kubernetes 网络策略，提供ACL功能。
文档地址：
kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml
修改calico.yaml
- 定义Pod网络（CALICO_IPV4POOL_CIDR），与前面pod CIDR配置一样
- 选择工作模式（CALICO_IPV4POOL_IPIP），支持**BGP（Never）**、**IPIP（Always）**、**CrossSubnet**（开启BGP并支持跨子网）
- name: CALICO_IPV4POOL_CIDR value: "10.244.0.0/16" - name: CALICO_IPV4POOL_VXLAN value: "Never"
部署Calico
kubectl apply -f calico.yaml [root@k8s-master ~]# kubectl get pods -n kube-system NAME READY STATUS RESTARTS AGE calico-kube-controllers-59877c7fb4-z2bms 1/1 Running 0 6m59s calico-node-pnjxq 1/1 Running 0 6m59s calico-node-v48jq 1/1 Running 0 6m59s coredns-7ff77c879f-dqk8t 1/1 Running 0 23m coredns-7ff77c879f-j8zsp 1/1 Running 0 23m etcd-k8s-master 1/1 Running 0 23m kube-apiserver-k8s-master 1/1 Running 0 23m kube-controller-manager-k8s-master 1/1 Running 0 23m kube-proxy-ck88h 1/1 Running 0 16m kube-proxy-hkb9f 1/1 Running 0 23m kube-scheduler-k8s-master 1/1 Running 0 23m
②
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml sed -i -r "s#quay.io/coreos/flannel:.*-amd64#lizhenliang/flannel:v0.11.0-amd64#g" kube-flannel.yml
6、
- 创建一个Pod,验证Pod工作
- 验证Pod网络通信
- 验证DNS解析
①查看集群状态
kubectl get cs NAME STATUS MESSAGE ERROR controller-manager Healthy ok scheduler Healthy ok etcd-0 Healthy {"health":"true"} kubectl get nodes NAME STATUS ROLES AGE VERSION k8s-master Ready master 28m v1.18.0 k8s-node1 Ready <none> 21m v1.18.0
②创建应用
kubectl create deployment nginx --image=nginx kubectl expose deployment nginx --port=80 --type=NodePort kubectl get pod,svc NAME READY STATUS RESTARTS AGE pod/nginx-f89759699-28gpp 1/1 Running 0 114s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 34m service/nginx NodePort 10.96.142.106 <none> 80:31233/TCP 73s
7、
kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0/aio/deploy/recommended.yaml
默认Dashboard只能集群内部访问，修改Service为NodePort类型，暴露到外部：
kind: Service apiVersion: v1 metadata: labels: k8s-app: kubernetes-dashboard name: kubernetes-dashboard namespace: kubernetes-dashboard spec: ports: - port: 443 targetPort: 8443 selector: k8s-app: kubernetes-dashboard
修改后
kind: Service apiVersion: v1 metadata: labels: k8s-app: kubernetes-dashboard name: kubernetes-dashboard namespace: kubernetes-dashboard spec: type: NodePort ports: - port: 443 targetPort: 8443 nodePort: 30001 selector: k8s-app: kubernetes-dashboard
创建service account并绑定默认cluster-admin管理员集群角色：
kubectl create serviceaccount dashboard-admin -n kube-system kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk ‘/dashboard-admin/{print $1}‘) #获取token命令