手把手带你搭建k8sKubernetes一个核心的特点就是能够自主的管理容器来保证云平台中的容器按照用户的期望状态运行着

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Kubernetes概述

准备镜像

建议使用CentOS-7.8进行安装 CentOS-7.8:下载地址

vm配置

建议：最少3台2核2G的配置

服务器整体规划

名称	IP
k8s-master	192.168.159.128
k8s-node1	192.168.159.129
k8s-node2	192.168.159.130

安装CentOS常用应用

由于小王是最小安装的所以许多常用应用没有安装需要自己手动安装

安装vim

yum install vim -y

安装ifconfig

yum install net-tools -y

准备工作

# 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
getenforce ## 查看selinux 状态

# 关闭swap
swapoff -a  # 临时
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久
free -g  ## 查看swap状态

# 根据规划设置主机名
hostnamectl set-hostname <hostname>

# 在master添加hosts
cat >> /etc/hosts << EOF
192.168.159.128 k8s-master
192.168.159.129 k8s-node1
192.168.159.130 k8s-node2
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

卸载旧版本的docker

sudo yum remove docker \
  docker-client \
  docker-client-latest \
  docker-common \
  docker-latest \
  docker-latest-logrotate \
  docker-logrotate \
  docker-engine

安装基础依赖

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

配置docker yum源

sudo yum-config-manager \
--add-repo \
http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

安装并设置开机启动 docker

yum install -y docker-ce-19.03.8 docker-ce-cli-19.03.8 containerd.io
systemctl enable docker
systemctl start docker

配置阿里云加速

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://rsj0shyq.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

安装k8s环境

配置K8S的yum源

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
       http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

卸载旧版本

yum remove -y kubelet kubeadm kubectl

安装kubelet、kubeadm、kubectl

yum install -y kubelet-1.17.3 kubeadm-1.17.3 kubectl-1.17.3

开机启动和重启kubelet

systemctl enable kubelet && systemctl start kubelet

创建一个shell脚本内容如下 vim images.sh

#!/bin/bash
images=(
  kube-apiserver:v1.17.3
    kube-proxy:v1.17.3
  kube-controller-manager:v1.17.3
  kube-scheduler:v1.17.3
  coredns:1.6.5
  etcd:3.4.3-0
    pause:3.1
)
for imageName in ${images[@]} ; do
    docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
done

给 images.sh 赋执行权限 chmod -R 700 images.sh 通过 sh images.sh 执行脚本
docker images 查看脚本下载的docker 镜像、

初始化master节点

kubeadm init \
--apiserver-advertise-address=192.168.159.128 \
--image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
--kubernetes-version v1.17.3 \
--service-cidr=10.96.0.0/16 \
--pod-network-cidr=10.244.0.0/16

--apiserver-advertise-address=192.168.159.128 这里的地址需要修改成master对应的IP地址。

红框部分建议复制出来 内容如下：

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 192.168.159.128:6443 --token gee67u.p8cz2d2ahu377hx7 \
    --discovery-token-ca-cert-hash sha256:7c63a464bce9509a1ae7340f135fc4190e7581f0ca0272a8a06fcd327197dc44

安装红框内容执行以下命令

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

部署网络插件calico

安装calico网络插件有坑：calico-3.22.0.yaml的部分内容进行了修改

### 下载calico 需要的docker镜像
docker pull calico/cni:v3.22.0
docker pull calico/kube-controllers:v3.22.0
docker pull calico/pod2daemon-flexvol:v3.22.0
docker pull calico/node:v3.22.0

获取 calico-3.22.0.yaml 将calico-3.22.0.yaml上传master服务器 kubectl apply -f calico-3.22.0.yaml

查看calico版本 kubectl describe deployment calico-kube-controllers -n kube-system
查看calico 运行情况 kubectl get pods -A

搭建完成通过 `kubectl get nodes` 在主节点查看节点运行的情况

如果calico 运行情况是Running并且k8s-master节点是Ready状态时方可将从节点加入到 master节点中。在从节点执行如下命令

kubeadm join 192.168.159.128:6443 --token gee67u.p8cz2d2ahu377hx7 \
    --discovery-token-ca-cert-hash sha256:7c63a464bce9509a1ae7340f135fc4190e7581f0ca0272a8a06fcd327197dc44

加入主节点后，在主节点上执行kubectl get node -o wide 查看每个node节点的健康状态

注意事项

关于令牌报错如果在两个从节点运行执行令牌报错：

   [ERROR FileContent--proc-sys-net-bridge-bridge-nf-call-iptables]: /proc/sys/net/bridge/bridge-nf-call-iptables contents are not set to 1
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
To see the stack trace of this error execute with --v=5 or higher

解决方案，两个从节点都执行以下命令：

echo "1" >/proc/sys/net/bridge/bridge-nf-call-iptables

如果超过2小时忘记了令牌，可以这样做kubeadm token create --print-join-command #打印新令牌

kubeadm token create --ttl 0 --print-join-command #创建个永不过期的令牌

手把手带你搭建k8s