使用kubeadm安装Kubernetes

1. Docker安装
   

   yum install -y yum-utils
   yum-config-manager --add-repo https://docs.docker.com/v1.13/engine/installation/linux/repo_files/centos/docker.repo
   yum makecache fast
   yum list docker-engine.x86_64 --showduplicates |sort -r
   rpm -qa | grep docker*
   yum install -y docker-engine-1.12.6
   systemctl start docker
   systemctl enable docker

   Kubernetes 1.6还没有针对docker 1.13和最新的docker 17.03上做测试和验证,所以这里安装Kubernetes官方推荐的Docker 1.12版本

2. 添加kubernetes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
   EOF
   
   cat >> /etc/sysctl.d/k8s.conf <<EOF
   net.bridge.bridge-nf-call-ip6tables = 1  net.bridge.bridge-nf-call-iptables = 1
   EOF
   
   sysctl -p /etc/sysctl.d/k8s.conf

3. 安装k8s服务
   yum install -y kubelet kubeadm kubectl kubernetes-cni
   systemctl enable kubelet.service
   systemctl restart kubelet.service
4. 所有节点添加hosts
   cat >> /etc/hosts <<EOF
   10.10.24.237 k8s-master
   10.10.24.236 k8s-node-1
   10.10.24.232 k8s-node-2
   EOF
5. 主节点初始化集群
   kubeadm init --kubernetes-version=v1.7.5 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=10.10.24.237
   网络问题无法从google下载容器镜像：
   [apiclient] Created API client, waiting for the control plane to become ready
   卡住需要执行kubeadm reset清理,重新执行
   init成功后k8s的核心组件均正常启动,以container的形式启动：ps -ef|grep kube
   为了使用kubectl访问apiserver,在~/.bash_profile中追加下面的环境变量：
   export KUBECONFIG=/etc/kubernetes/admin.conf
   source ~/.bash_profile
   此时kubectl命令在master node上就可以用了,查看一下当前机器中的Node：
   kubectl get nodes
6. 向集群中添加节点
   将node1和node2加入集群，分别在node1和node2上执行：
   kubeadm join --token e7986d.e440de5882342711 10.10.24.237:6443
   使master node参与工作负载
   kubectl taint nodes --all node-role.kubernetes.io/master-
   使用kubeadm初始化的集群，出于安全考虑Pod不会被调度到Master Node上，也就是说Master Node不参与工作负载
7. 所有节点安装flannel pod网络
   kubectl create -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel-rbac.yml
   kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
   serviceaccount "flannel" created
   configmap "kube-flannel-cfg" created
   daemonset "kube-flannel-ds" created
   ps -ef|grep kube|grep flannel
   使用kubectl get pod --all-namespaces -o wide确保所有的Pod都处于Running
8. 安装Dashboard插件
   wget https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/kubernetes-dashboard.yaml
   kubectl create -f kubernetes-dashboard.yaml
   kubectl create -f kube-dashboard-rbac.yml

   kind: ClusterRoleBinding
   apiVersion: rbac.authorization.k8s.io/v1beta1
   metadata:
   name: dashboard-admin
   roleRef:
   apiGroup: rbac.authorization.k8s.io
   kind: ClusterRole
   name: cluster-admin
   subjects:
   - kind: ServiceAccount
   name: default
   namespace: kube-system

   kubectl create -f dashboard-rbac.yml

9. 在集群中运行Heapster 
   wget https://github.com/kubernetes/heapster/archive/v1.3.0.tar.gz
   tar -zxvf v1.3.0.tar.gz
   cd heapster-1.3.0/deploy/kube-config/influxdb
   kubectl create -f ./
   deployment "monitoring-grafana" created
   service "monitoring-grafana" created
   deployment "heapster" created
   service "heapster" created
   deployment "monitoring-influxdb" created
   service "monitoring-influxdb" created