kubeadm安装HA集群
鉴于使用二进制的方式安装较为复杂,且不太好处理证书的生成,分发等问题,并且对性能没有较高的要求,所以强烈推荐使用此模式,具体下来这个模式的好处为:
- 官方提供的工具,有官方的文档支持
- 安装贼简单,没有其他的依赖
- 扩展性强,有官方的一些扩展支持
- 集群全部以容器启动,所以没那么多你需要管理的service
准备
硬件
- 一台或多台运行 Ubuntu 16.04 + 的主机(其他linux系统也行)
- 集群中完整的网络连接,公网或者私网都可以
各节点环境
- #### docker
使用加入器安装docker
curl https://releases.rancher.com/install-docker/17.03.sh | sh
- #### 禁用swap
然后需要禁用 swap 文件,这是 Kubernetes 的强制步骤。编辑/etc/fstab
文件,注释掉引用swap
的行,保存并重启后输入sudo swapoff -a
即可
vim /etc.fastab
#注释调swap的行
sudo swapoff -a
设置源
sudo apt-get update && sudo apt-get install -y apt-transport-https curl -s https://gitee.com/tanx/kubernetes-test/raw/master/kubeadm/apt-key.gpg | sudo apt-key add - sudo cat <<EOF >/etc/apt/sources.list.d/kubernetes.list deb http://mirrors.ustc.edu.cn/kubernetes/apt/ kubernetes-xenial main EOF
安装master
安装kubelet,kubeadm,kubectl
sudo apt-get update sudo apt-get install -y kubelet kubeadm kubectl
编辑 kubeadm 配置文件
kubeadm-config.yaml
apiVersion: kubeadm.k8s.io/v1beta1 kind: ClusterConfiguration imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers kubernetesVersion: v1.13.1 controlPlaneEndpoint: k8s-cluster.smile13.com:6443 #你的k8s的访问地址 apiServer: certSANs: - k8s-cluster.smile13.com ##你的k8s的访问地址 networking: serviceSubnet: 10.96.0.0/12 podSubnet: 192.168.0.0/16 dnsDomain: "cluster.local"
完整的可以参考
https://godoc.org/k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta1
提前拉取镜像(可选)
kubeadm config images pull --config kubeadm-config.yaml
初始化master1
[root@k8s01 ~]# kubeadm init --config kubeadm-config.yaml [init] Using Kubernetes version: v1.13.1 [preflight] Running pre-flight checks [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' [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env" [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml" [kubelet-start] Activating the kubelet service [certs] Using certificateDir folder "/etc/kubernetes/pki" [certs] Generating "ca" certificate and key [certs] Generating "apiserver" certificate and key [certs] apiserver serving cert is signed for DNS names [k8s01 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local k8s-cluster.smile13.com k8s-cluster.smile13.com] and IPs [10.96.0.1 192.168.158.131] [certs] Generating "apiserver-kubelet-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 [k8s01 localhost] and IPs [192.168.158.131 127.0.0.1 ::1] [certs] Generating "etcd/peer" certificate and key [certs] etcd/peer serving cert is signed for DNS names [k8s01 localhost] and IPs [192.168.158.131 127.0.0.1 ::1] [certs] Generating "etcd/healthcheck-client" certificate and key [certs] Generating "apiserver-etcd-client" certificate and key [certs] Generating "front-proxy-ca" certificate and key [certs] Generating "front-proxy-client" certificate and key [certs] Generating "sa" key and public key [kubeconfig] Using kubeconfig folder "/etc/kubernetes" [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 [control-plane] Using manifest folder "/etc/kubernetes/manifests" [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" [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 28.003045 seconds [uploadconfig] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace [kubelet] Creating a ConfigMap "kubelet-config-1.13" in namespace kube-system with the configuration for the kubelets in the cluster [patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "k8s01" as an annotation [mark-control-plane] Marking the node k8s01 as control-plane by adding the label "node-role.kubernetes.io/master=''" [mark-control-plane] Marking the node k8s01 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule] [bootstrap-token] Using token: t1yovr.ag1xbdhfgo36z8f7 [bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles [bootstraptoken] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials [bootstraptoken] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token [bootstraptoken] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster [bootstraptoken] creating the "cluster-info" ConfigMap in the "kube-public" namespace [addons] Applied essential addon: CoreDNS [addons] Applied essential addon: kube-proxy 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 k8s-cluster.smile13.com:6443 --token t1yovr.ag1xbdhfgo36z8f7 --discovery-token-ca-cert-hash sha256:ceaf1b9a9ef558ff8706331cb88e81c28d48528972cee2b92a8416364768e45d [root@k8s01 ~]# mkdir -p $HOME/.kube [root@k8s01 ~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config [root@k8s01 ~]# chown $(id -u):$(id -g) $HOME/.kube/config
查看集群状态
[root@k8s01 ~]# kubectl get cs NAME STATUS MESSAGE ERROR controller-manager Healthy ok scheduler Healthy ok etcd-0 Healthy {"health": "true"} [root@k8s01 ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION k8s01 NotReady master 4m45s v1.13.1
安装网络插件
kubectl apply -f https://docs.projectcalico.org/v3.3/getting-started/kubernetes/installation/hosted/rbac-kdd.yaml kubectl apply -f https://docs.projectcalico.org/v3.3/getting-started/kubernetes/installation/hosted/kubernetes-datastore/calico-networking/1.7/calico.yaml
复制安装文件到其他master
[root@k8s01 k8s-install]# cd /etc/kubernetes && tar cvzf k8s-key.tgz pki/ca.* pki/sa.* pki/front-proxy-ca.* pki/etcd/ca.* admin.conf pki/ca.crt pki/ca.key pki/sa.key pki/sa.pub pki/front-proxy-ca.crt pki/front-proxy-ca.key pki/etcd/ca.crt pki/etcd/ca.key admin.conf [root@k8s01 kubernetes]# scp /etc/kubernetes/k8s-key.tgz k8s02:/etc/kubernetes/ [root@k8s01 kubernetes]# scp /etc/kubernetes/k8s-key.tgz k8s03:/etc/kubernetes/ ######到对应的master解压k8s-key.tgz包 ######复制kubeadm-config.yaml到其他master(用于从阿里云下载镜像,也可以不复制,直接pull需要的镜像,这里我为了方便直接copy配置文件进行pull) [root@k8s01 ~]# scp k8s-install/kubeadm-config.yaml k8s02:~ kubeadm-config.yaml [root@k8s01 ~]# scp k8s-install/kubeadm-config.yaml k8s03:~ kubeadm-config.yaml
原理
在进行更改之前,运行一系列飞行前检查以验证系统状态。
生成自签名CA(或使用现有CA),以便为群集中的每个组件设置标识。如果用户通过将其放入通过
--cert-dir
(/etc/kubernetes/pki
默认情况下)配置的cert目录中提供了自己的CA证书和/或密钥,则会跳过此步骤。将kubeconfig文件写入kubelet
/etc/kubernetes/
,控制器管理器和调度程序以用于连接到API服务器,每个API服务器都有自己的标识,以及另一个用于管理命名的kubeconfig文件admin.conf
。为API服务器,控制器管理器和调度程序生成静态Pod清单。如果未提供外部etcd,则会为etcd生成其他静态Pod清单。
安装其他master
拉取镜像
kubeadm config images pull --config kubeadm-config.yaml
初始化master
kubeadm join k8s-cluster.smile13.com:6443 --token t1yovr.ag1xbdhfgo36z8f7 --discovery-token-ca-cert-hash sha256:ceaf1b9a9ef558ff8706331cb88e81c28d48528972cee2b92a8416364768e45d --experimental-control-plane
一定注意此处加入了新的参数–experimental-control-plane
查看集群状态
[root@k8s01 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s01 Ready master 31m v1.13.1
k8s02 Ready master 4m51s v1.13.1