centos7 k8s 1master+2node 集群配置

0 环境

软件	版本
centos	CentOS Linux release 7.8.2003
docker	Docker version 19.03.8, build afacb8b
k8s	1.18.2

ip	角色	hostname
192.168.6.101	master	master01
192.168.6.102	node	node01
192.168.6.103	node	node02

1 centos7 优化（所有节点）

1.1 改阿里源

如果安装[2.2 安装docker-ce]有问题，则此步骤去掉

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
yum update -y
yum clean all
yum makecache

1.2 关闭防火墙

firewall-cmd --state        #查看防火墙状态
systemctl stop firewalld.service        #停止firewall
systemctl disable firewalld.service     #禁止firewall开机启动

1.3 关闭selinux

getenforce  #查看selinux状态
vi /etc/selinux/config

将SELINUX=enforcing改为SELINUX=disabled

1.4 安装命令补全bash-completion

yum install -y bash-completion

2 安装docker（所有节点）

2.1 删除原有的docker软件

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

2.2 安装docker-ce

yum install -y yum-utils
yum-config-manager     --add-repo     https://download.docker.com/linux/centos/docker-ce.repo
yum install docker-ce docker-ce-cli containerd.io
systemctl start docker #启动docker
systemctl enable docker #设置为系统服务
docker -v # 验证docker是否安装成功

2.3 配置阿里镜像实现docker下载加速

mkdir -p /etc/docker
tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://[自己配置的docker加速].mirror.aliyuncs.com","https://registry.docker-cn.com"]
}
EOF

重启生效

如何配置阿里镜像加速，请参考传送门

2.4 免sudo运行docker命令（可选）

sudo groupadd docker #添加用户组(如果没有docker组的话)
sudo gpasswd -a ${USER} docker #把当前用户添加到docker用户组
sudo systemctl daemon-reload #重载配置文件
sudo systemctl restart docker  #重启docker服务

3 K8S群集

3.1 配置hosts、hostname（所有节点）

修改/etc/hosts文件

199.232.68.133 raw.githubusercontent.com #非必须，如果无法从github下载文件，可以配置次行试试
192.168.6.101 master01
192.168.6.102 node01
192.168.6.103 node02

对应主机修改/etc/hostname文件

3.2 禁用swap（所有节点）

修改配置文件/etc/fstab

vi /etc/fstab 

注释下面这一行

/mnt/swap swap swap defaults 0 0

修改/etc/sysctl.conf文件下vm.swappiness参数

echo vm.swappiness=0 >> /etc/sysctl.conf

使用free -m验证是否关闭成功

3.3 内核参数修改（所有节点）

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

sysctl -p /etc/sysctl.d/k8s.conf

3.4 安装Kubernetes源（所有节点）

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

更新缓存

yum clean all
yum -y makecache	

安装kubelet、kubeadm、kubectl

yum install -y kubelet kubeadm kubectl

安装结果

Installed:
  kubeadm.x86_64 0:1.18.2-0   kubectl.x86_64 0:1.18.2-0   kubelet.x86_64 0:1.18.2-0  

Dependency Installed:
  conntrack-tools.x86_64 0:1.4.4-7.el7                                               
  cri-tools.x86_64 0:1.13.0-0                                                        
  kubernetes-cni.x86_64 0:0.7.5-0                                                    
  libnetfilter_cthelper.x86_64 0:1.0.0-11.el7                                        
  libnetfilter_cttimeout.x86_64 0:1.0.0-7.el7                                        
  libnetfilter_queue.x86_64 0:1.0.2-2.el7_2                                          
  socat.x86_64 0:1.7.3.2-2.el7            

启动并将kubelet配置为系统服务

systemctl enable kubelet && systemctl start kubelet

3.5 master配置

生成默认配置文件

cd ~
mkdir k8s
cd k8s
kubeadm config print init-defaults ClusterConfiguration > kubeadm.conf

修改kubeadm.conf配置文件

mageRepository修改为

imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers 

advertiseAddress修改为master01的ip

localAPIEndpoint:
  advertiseAddress: 192.168.6.101

修改k8s的实际版本号

kubernetesVersion: v1.18.2

配置podSubnet

podSubnet: 10.244.0.0/16

根据kubeadm.conf配置文件下载镜像

kubeadm config images pull --config ./kubeadm.conf

根据kubeadm.conf初始化环境

sudo kubeadm init --config ./kubeadm.conf

下载成功如有如下提示，要记录好kubeadm join 192.168.6.101:6443 ...这段命令，这段命令用于配置node环境

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 192.168.6.101:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:d60829461dcbfd149c00b41e2baa3c500d9a459840578faf2c0a6e33635fc9fd

创建配置文件并赋予权限，重启kubelet服务

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

配置flannel覆盖网络工具

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
kubectl apply -f  kube-flannel.yml

验证master01是否配置成功

kubectl get nodes

配置成功会如下图所示，status为Ready

将master01上的配置文件通过scp拷贝到node01、node02上

sudo scp /etc/kubernetes/admin.conf lovewinner@node01:/home/lovewinner
sudo scp /home/lovewinner/k8s/kube-flannel.yml lovewinner@node01:/home/lovewinner

sudo scp /etc/kubernetes/admin.conf lovewinner@node02:/home/lovewinner
sudo scp /home/lovewinner/k8s/kube-flannel.yml lovewinner@node02:/home/lovewinner

3.6 node配置（node01、node02配置）

创建配置文件并赋予权限

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

加入到集群中

sudo kubeadm join 192.168.6.101:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:d60829461dcbfd149c00b41e2baa3c500d9a459840578faf2c0a6e33635fc9fd

配置flannel覆盖网络工具

cd /home/lovewinner
kubectl apply -f kube-flannel.yml

3.7 安装控制面板（master01配置）

下载配置文件

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0/aio/deploy/recommended.yaml

修改配置文件

spec:
  type: NodePort #添加此属性
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30443  #添加此属性

更新配置

kubectl apply -f recommended.yaml

浏览器访问https://master01:30443 ，登录dashboard

创建dashboard-adminuser.yaml，并复制下面内容

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard  

创建登录用户

kubectl apply -f dashboard-adminuser.yaml

查看token

kubectl -n kubernetes-dashboard describe secret $(kubectl -n kubernetes-dashboard get secret | grep admin-user | awk '{print $1}')

执行完以后如下所示

Name:         admin-user-token-6hw6v
Namespace:    kubernetes-dashboard
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: admin-user
              kubernetes.io/service-account.uid: 5b5af84f-0266-47f3-9b9a-5d51117be850

Type:  kubernetes.io/service-account-token

Data
====
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6Inp5NmRITFR4SjNGaWN2b1pQd2RyRnlqcjZDSmJOZmV3VnhCcFhYS2RSeWsifQ.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.v2-KCiTnQcK60Sw_Ey_0p3Fvln8U1HbzlVV9JBcPu3eXXzpMliRPDQEJJ9V0wewyZk5zo6pub2g7Gv8xla2H3krosnAfucVnPKpRgyxVtKdhdst2SdQr0TZZ0tTd-wGq0Gjoti1UQcZsvQaNeE6NALrDdeEcuziMGOZVnW1qpwx8sBceK4h0GVas3LE7j1vQPBH3w_qaNA_JY_NeQNZe0UCZXCNkBjtTnaWfQh2lXcal5UuzUWqsEcd42t9qh63GyX04wwG85jJbP0zerwpB0M8LN3axzM-hojxvOwYSvUbR7Ws4igKYDbdFez6_oViqE3SIvQJU1Xs-twOm9zzQ9A
ca.crt:     1025 bytes
namespace:  20 bytes

参考资源

• https://blog.51cto.com/3241766/2405624
• https://blog.csdn.net/networken/article/details/85607593