Kubernetes——一种较为简便的安装方式

搭建K8s集群[无需翻墙]

一种较为简单的方式

• 环境要求

• 由于条件有限，准备了两台虚拟主机Centos7.x（裸机）
  –在安装过程中能够体会到2台或者更多台机器的安装过程类似

软件版本

Docker       18.09.0
---
kubeadm-1.14.0-0 
kubelet-1.14.0-0 
kubectl-1.14.0-0
---
k8s.gcr.io/kube-apiserver:v1.14.0
k8s.gcr.io/kube-controller-manager:v1.14.0
k8s.gcr.io/kube-scheduler:v1.14.0
k8s.gcr.io/kube-proxy:v1.14.0
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.3.10
k8s.gcr.io/coredns:1.3.1
---
calico:v3.9

更新yum源

所有机器都需要执行

yum -y update
yum install -y conntrack ipvsadm ipset jq sysstat curl iptables libseccomp

# 安装 wget 配置阿里镜像源
yum install -y wget
cd /etc/yum.repos.d/
mv CentOS-Base.repo CentOS-Base.repo.back
wget -O CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
yum clean all
yum makecache

安装Docker

01 安装必要的依赖
 sudo yum install -y yum-utils device-mapper-persistent-data lvm2
 
02 设置docker仓库
	sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
	
3.【设置要设置一下阿里云镜像加速器】这里通过登录阿里云账户获取主机的实际地址
sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
"registry-mirrors": ["这边替换成自己的实际地址"]
}
EOF
4.重新加载生效
sudo systemctl daemon-reload


5.安装docker
yum install -y docker-ce-18.09.0 docker-ce-cli-18.09.0 containerd.io

04 启动docker  并设置开机启动
sudo systemctl start docker && sudo systemctl enable docker

修改hosts文件

master节点

# 设置master的hostname，并且修改hosts文件
sudo hostnamectl set-hostname m

vi /etc/hosts

192.168.121.138 m
192.168.121.140 w1

worker节点

# 设置worker01/02的hostname，并且修改hosts文件
sudo hostnamectl set-hostname w1

vi /etc/hosts
192.168.121.138 m
192.168.121.140 w1

ping测试

m:   ping w1
w1:  ping m

系统基础前提配置

# (1)关闭防火墙
systemctl stop firewalld && systemctl disable firewalld

# (2)关闭selinux
setenforce 0
sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

# (3)关闭swap
swapoff -a
sed -i '/swap/s/^\(.*\)$/#\1/g' /etc/fstab

# (4)配置iptables的ACCEPT规则
iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat && iptables -P FORWARD ACCEPT

# (5)设置系统参数
cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

sysctl --system

Installing kubeadm, kubelet and kubectl

配置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

安装kubeadm&kubelet&kubectl

# 查看排序
yum list kubeadm --showduplicates | sort -r

cri-tools-1.13.0-0.x86_64 来自 kubernetes
kubeadm-1.14.0-0.x86_64 来自 kubernetes
kubectl-1.14.0-0.x86_64 来自 kubernetes
kubelet-1.14.0-0.x86_64 来自 kubernetes
kubernetes-cni-0.8.7-0.x86_64 来自 kubernetes
socat-1.7.3.2-2.el7.x86_64 来自 base


# 安装
yum install -y kubeadm-1.14.0-0 kubelet-1.14.0-0 kubectl-1.14.0-0 --skip-broken

# 这里安装报错，分别执行如下命令分别安装各个组件
yum install -y cri-tools-1.13.0-0.x86_64
yum install -y kubeadm-1.14.0-0.x86_64
yum install -y kubectl-1.14.0-0.x86_64
yum install -y kubelet-1.14.0-0.x86_64
yum install -y kubernetes-cni-0.8.7-0.x86_64
yum install -y socat-1.7.3.2-2.el7.x86_64

docker和k8s设置同一个cgroup

# docker  在 daemon.json文件中增加如下配置，注意使用 ,  隔开
vi /etc/docker/daemon.json
    "exec-opts": ["native.cgroupdriver=systemd"],
# 重启docker
systemctl restart docker
    
# kubelet，这边如果发现输出directory not exist，是没问题的
sed -i "s/cgroup-driver=systemd/cgroup-driver=cgroupfs/g" /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
# 启动 kubernetes
systemctl enable kubelet && systemctl start kubelet

proxy/pause/scheduler等国内镜像

(1)查看kubeadm使用的镜像

kubeadm config images list

可以发现这里都是国外的镜像

k8s.gcr.io/kube-apiserver:v1.14.0
k8s.gcr.io/kube-controller-manager:v1.14.0
k8s.gcr.io/kube-scheduler:v1.14.0
k8s.gcr.io/kube-proxy:v1.14.0
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.3.10
k8s.gcr.io/coredns:1.3.1

(2)解决国外镜像不能访问的问题

• 创建kubeadm.sh脚本，用于拉取镜像/打tag/删除原有镜像

#!/bin/bash

set -e

KUBE_VERSION=v1.14.0
KUBE_PAUSE_VERSION=3.1
ETCD_VERSION=3.3.10
CORE_DNS_VERSION=1.3.1

GCR_URL=k8s.gcr.io
ALIYUN_URL=registry.cn-hangzhou.aliyuncs.com/google_containers

images=(kube-proxy:${KUBE_VERSION}
kube-scheduler:${KUBE_VERSION}
kube-controller-manager:${KUBE_VERSION}
kube-apiserver:${KUBE_VERSION}
pause:${KUBE_PAUSE_VERSION}
etcd:${ETCD_VERSION}
coredns:${CORE_DNS_VERSION})

for imageName in ${images[@]} ; do
  docker pull $ALIYUN_URL/$imageName
  docker tag  $ALIYUN_URL/$imageName $GCR_URL/$imageName
  docker rmi $ALIYUN_URL/$imageName
done

• 运行脚本和查看镜像

# 运行脚本
sh ./kubeadm.sh

# 查看镜像
docker images

• 将这些镜像推送到自己的阿里云仓库【可选，根据自己实际的情况】

kube init初始化master

初始化master节点（在主节点上执行）

kubeadm init --kubernetes-version=1.14.0 --apiserver-advertise-address=本地IP --pod-network-cidr=10.244.0.0/16

#  我在安装的过程中报错，版本不对应，重新下载对应版本
yum -y remove kubelet
yum -y install kubelet-1.14.0
yum -y install kubeadm-1.14.0

• 安装成功日志如下，从节点使用末尾的 kubeadm join 命令加入到集群中

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 192.168.121.138:6443 --token y4yylq.ev18cfq87ic0yqmz \
    --discovery-token-ca-cert-hash sha256:af4b166caaaacb231fc33027fdb7d6a6c2bb455dd3a478fe84e191ade0d5819b 

• 验证主节点

---报错
The connection to the server localhost:8080 was refused - did you specify the right host or port?
    
[解决办法]
ll /etc/kubernetes/admin.conf
echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
source ~/.bash_profile

• 再次验证，可以发现主节点部署成功

kubectl get pods -n kube-system  

健康检查

curl -k https://localhost:6443/healthz

输出  ok

部署calico网络插件

网络插件起到协助通信的作用

calico，同样在master节点上操作

# 在k8s中安装calico
kubectl apply -f https://docs.projectcalico.org/v3.9/manifests/calico.yaml

# 确认一下calico是否安装成功
kubectl get pods --all-namespaces -w

kube join–从节点假如

master节点的最后打印信息，在从节点中执行

kubeadm join 192.168.121.138:6443 --token y4yylq.ev18cfq87ic0yqmz \
    --discovery-token-ca-cert-hash sha256:af4b166caaaacb231fc33027fdb7d6a6c2bb455dd3a478fe84e191ade0d5819b 

检查集群信息

kubectl get nodes

NAME                   STATUS   ROLES    AGE     VERSION
master-kubeadm-k8s     Ready    master   19m     v1.14.0
worker01-kubeadm-k8s   Ready    <none>   3m6s    v1.14.0
worker02-kubeadm-k8s   Ready    <none>   2m41s   v1.14.0

在加入从节点的时候，报错  
not found /etc/kubernetes/admin.conf
然后拷贝主节点的admin.conf文件到从节点中
修改  .bash_profile 并重启