半小时搭建一套带Dashboard的kubernetes（K8S）集群
K8S
kubernetes（K8S）是什么
Kubernetes（常简称为K8S）是用于自动部署、扩展和管理容器化（containerized）应用程序的开源系统。系统由Google设计并捐赠给Cloud Native Computing Foundation（今属Linux基金会）来使用。
它旨在提供“跨主机集群的自动部署、扩展以及运行应用程序容器的平台”。它支持一系列容器工具, 包括Docker等。我们可以将Docker看成Kubernetes内部使用的低级别组件。
为什么要使用kubernetes
Docker这个新兴的容器化技术当前应用越来越广，并且其从单机走向集群也称为必然，而云计算的蓬勃发展正在加速这一进程。kubernetes作为当前普遍被业界广泛认可和看好的docker分布式系统解决方案，前景非常可观。
使用Kubernetes可以做什么：
- 自动化容器的部署和复制
- 随时扩展或收缩容器规模
- 将容器组织成组，并且提供容器间的负载均衡
- 很容易地升级应用程序容器的新版本
- 提供容器弹性，如果容器失效就替换它
部署环境准备
机器信息
机器信息
关闭防火墙及selinux
# systemctl stop firewalld # systemctl disable firewalld # setenforce 0
修改hosts
172.17.0.218 k8sm-218 172.17.0.219 k8s-219 172.17.0.220 k8s-220
增加网络转发
# cat <<EOF > /etc/sysctl.d/k8s.conf net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 EOF # sysctl --system //使配置生效
安装组件
安装指定版本Docker
# wget -O /etc/yum.repos.d/docker-ce.repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo # yum install docker-ce-18.06.1.ce-3.el7 -y # systemctl start docker # systemctl enable docker
安装指定版本kubelet，kubeadm，kubectl
# 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 # yum install kubelet-1.13.3 -y # yum install kubeadm-1.13.3 -y # yum install kubectl-1.13.3 -y # systemctl enable kubelet
初始化master
# kubeadm init --kubernetes-version=v1.13.3 --apiserver-advertise-address=172.17.0.218 --image-repository registry.aliyuncs.com/google_containers --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12
参数含义：
--kubernetes-version：指定kubeadm版本；
--pod-network-cidr：指定pod所属网络
--image-repository 指定下载源
--service-cidr：指定service网段,负载均衡ip
--ignore-preflight-errors=Swap/all：忽略 swap/所有 报错
初始化成功结果
Your Kubernetes master 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 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 machines by running the following on each node as root: kubeadm join 172.17.0.218:6443 --token ai3bxc.zgq33i1sbdybhnci --discovery-token-ca-cert-hash sha256:20cb9ccc07e2612bc3b31bd7b5e8909bdbd3d293e7c7f4c18dbee6f62ea94788
增加kubectl权限访问
此处为初始化成功输出的内容，复制即可
# mkdir -p $HOME/.kube # sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config # sudo chown $(id -u):$(id -g) $HOME/.kube/config
安装pod网络组件
# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
增加node到集群里
// master初始化后的命令 # kubeadm join 172.17.0.218:6443 --token ai3bxc.zgq33i1sbdybhnci --discovery-token-ca-cert-hash sha256:20cb9ccc07e2612bc3b31bd7b5e8909bdbd3d293e7c7f4c18dbee6f62ea94788
master节点查看node状态
# kubectl get node NAME STATUS ROLES AGE VERSION k8s-219 Ready <none> 112m v1.13.3 k8s-220 Ready <none> 113m v1.13.3 k8sm-218 Ready master 162m v1.13.3
部署webui dashboard
下载官方的yaml文件:
# wget https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml
修改两个地方
第一个是修改镜像,kubernetes-dashboard.yaml配置文件112行
90 # ------------------- Dashboard Deployment ------------------- # 91 92 kind: Deployment 93 apiVersion: apps/v1 94 metadata: 95 labels: 96 k8s-app: kubernetes-dashboard 97 name: kubernetes-dashboard 98 namespace: kube-system 99 spec: 100 replicas: 1 101 revisionHistoryLimit: 10 102 selector: 103 matchLabels: 104 k8s-app: kubernetes-dashboard 105 template: 106 metadata: 107 labels: 108 k8s-app: kubernetes-dashboard 109 spec: 110 containers: 111 - name: kubernetes-dashboard 112 #image: k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.1 113 image: mirrorgooglecontainers/kubernetes-dashboard-amd64:v1.10.0 114 ports: 115 - containerPort: 8443 116 protocol: TCP
第二个是添加一个type,指定端口类型为 NodePort，这样外界可以通过地址 nodeIP:nodePort 访问 dashboard,kubernetes-dashboard.yaml配置文件158行:
148 # ------------------- Dashboard Service ------------------- # 149 150 kind: Service 151 apiVersion: v1 152 metadata: 153 labels: 154 k8s-app: kubernetes-dashboard 155 name: kubernetes-dashboard 156 namespace: kube-system 157 spec: 158 type: NodePort 159 ports: 160 - port: 443 161 targetPort: 8443 162 selector: 163 k8s-app: kubernetes-dashboard
部署到k8s集群
# kubectl apply -f kubernetes-dashboard.yaml # kubectl get pods -n kube-system |grep dashboard kubernetes-dashboard-6685cb584f-xlk2h 1/1 Running 0 98s # kubectl get pods,svc -n kube-system NAME READY STATUS RESTARTS AGE pod/coredns-78d4cf999f-5hcjm 1/1 Running 0 3h21m pod/coredns-78d4cf999f-6mlql 1/1 Running 0 3h21m pod/etcd-k8sm-218 1/1 Running 0 3h20m pod/kube-apiserver-k8sm-218 1/1 Running 0 3h19m pod/kube-controller-manager-k8sm-218 1/1 Running 0 3h20m pod/kube-flannel-ds-amd64-6kfhg 1/1 Running 0 3h13m pod/kube-flannel-ds-amd64-c4fr4 1/1 Running 0 152m pod/kube-flannel-ds-amd64-qhc2w 1/1 Running 0 151m pod/kube-proxy-7hntq 1/1 Running 0 151m pod/kube-proxy-b4txb 1/1 Running 0 3h21m pod/kube-proxy-bz529 1/1 Running 0 152m pod/kube-scheduler-k8sm-218 1/1 Running 0 3h20m pod/kubernetes-dashboard-6685cb584f-xlk2h 1/1 Running 0 3m5s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP 3h21m service/kubernetes-dashboard NodePort 10.104.4.26 <none> 443:31667/TCP 3m5s
通过https访问ui
登录页
Token （令牌） 认证方式登录
1）授权 (所有 namespace )
// 创建serviceaccount # kubectl create serviceaccount dashboard-serviceaccount -n kube-system // 创建clusterrolebinding # kubectl create clusterrolebinding dashboard-cluster-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-serviceaccount
2）获取令牌（用于网页登录）
// 查看口令列表 # kubectl get secret -n kube-system |grep dashboard-serviceaccount-token dashboard-serviceaccount-token-f45wg kubernetes.io/service-account-token 3 22s // 获取口令 # kubectl describe secret dashboard-serviceaccount-token-f45wg -n kube-system
3）将获取到的token放在令牌里
输入token
4）登录成功
K8S UI
至此，K8S集群+Dashboard搭建成功！
后记
此篇不涉及理论，面向对象是刚接触K8S的朋友，最小成本来搭建一套K8S集群，以最快时间来看到效果，增加学习的信心^_^
请先 后发表评论～