kubeadmin快速安装k8s集群

个人办公环境，通过VM workstation NAT模式快速安装k8s集群用于本地测试，本次安装版本v1.15.0.

一、安装kubeadm环境准备

主机	IP
k8s-master01	192.168.68.150
node01	192.168.68.151
node02	192.168.68.152

以下操作，在三台节点执行

1. 关闭防火墙及selinux

systemctl stop firewalld && systemctl disable firewalld

sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config && setenforce 0

2. 关闭 swap 分区

swapoff -a 临时

sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab 永久

3. 分别在192.168.68.150/151/152上设置主机名及配置hosts

hostnamectl set-hostname k8s-master（192.168.68.150主机打命令）
hostnamectl set-hostname node01（192.168.68.151主机打命令）
hostnamectl set-hostname node02 (192.168.68.152主机打命令)

4. 在所有主机上上添加如下命令

cat >> /etc/hosts << EOF
192.168.68.150 k8s-master
192.168.68.151 node01
192.168.68.152 node02
EOF

5. 内核调整,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

6. 设置系统时区并同步时间服务器
   yum install -y ntpdate && ntpdate time.windows.com

7. docker 安装&配置

安装依赖

yum install -y yum-utils device-mapper-persistent-data lvm2

设置yum源

yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

可以查看所有仓库中所有docker版本，并选择特定版本安装`

yum list docker-ce --showduplicates | sort -r

yum -y install docker-ce-18.06.1.ce-3.el7

启动并加入开机启动

systemctl start docker && systemctl enable docker

配置镜像加速器（阿里云/可选）

8. 添加kubernetes YUM软件源

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

9. 安装kubeadm,kubelet和kubectl

yum install -y kubelet-1.15.0-0 kubeadm-1.15.0-0 kubectl-1.15.0-0

二、部署Kubernetes Master

只需要在Master 节点执行，这里的apiserve需要修改成自己的master地址

kubeadm init \
--apiserver-advertise-address=192.168.68.150 \
--image-repository registry.aliyuncs.com/google_containers \
--kubernetes-version v1.17.0 \
--service-cidr=10.1.0.0/16 \
--pod-network-cidr=10.244.0.0/16

由于默认拉取镜像地址k8s.gcr.io国内无法访问，这里指定阿里云镜像仓库地址,输出信息：

[bootstrap-token] Using token: zh8qer.f6q4sixlsulxi2tp
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[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
[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:

  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/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 192.168.68.129:6443 --token zh8qer.f6q4sixlsulxi2tp \
    --discovery-token-ca-cert-hash sha256:4fd045390a800653f081b0618d74e1d24c84a4dcf8baeb79878d3c7152bbe7ef 

根据输出提示操作：

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

加入k8s node节点，分别在两个Node节点 192.168.68.151/192.168.68.152执行
kubeadm join 192.168.68.129:6443 --token zh8qer.f6q4sixlsulxi2tp \ --discovery-token-ca-cert-hash sha256:4fd045390a800653f081b0618d74e1d24c84a4dcf8baeb79878d3c7152bbe7ef

输出提示内容

[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.

三、安装网络插件

本次集群安装采用flannel网络插件

只需要在Master节点执行

wget https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml

kubectl apply -f kube-flannel.yml

查看集群node状态
查看集群的node状态，安装完网络工具之后，只有显示如下状态，所有节点全部都Ready好了之后才能继续后面的操作

kubectl get nodes

四、测试Kubernetes集群

在Kubernetes集群中创建一个pod，然后暴露端口，验证是否正常访问

kubectl create deployment nginx --image=nginx

kubectl expose deployment nginx --port=80 --type=NodePort

kubectl get pods,svc

访问地址：http://NodeIP:Port ,此例就是：http://192.168.68.152:30667