超简单kubernetes 高可用集群版安装

前置条件

• 系统要求:64位centos7.6
• 关闭防火墙和selinux
• 关闭操作系统swap分区(使用k8s不推荐打开)
• 请预配置好每个节点的hostname保证不重名即可
• 请配置第一个master能秘钥免密登入所有节点(包括自身)

环境说明

本手册安装方式适用于小规模使用

多主模式(最少三个), 每个master节点上需要安装keepalived

准备工作(每个节点都需要执行)

Docker和kubernetes软件源配置

# 切换到配置目录
cd /etc/yum.repos.d/
# 配置docker-ce阿里源
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# 配置kubernetes阿里源
cat < /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

配置内核相关参数

cat <  /etc/sysctl.d/ceph.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system

安装相应软件包

# 安装kubeadm kubelet kubectl
yum install kubeadm kubectl kubelet -y

# 开机启动kubelet和docker
systemctl enable docker kubelet

# 启动docker
systemctl start docker

部署

安装keepalived(在所有master上执行)

# 此处如果有Lb可省略 直接使用LB地址
# 安装时候请先在初始化master上执行,保证VIP附着在初始化master上,否则请关闭其他keepalived

# 安装完成后可根据自己业务需要实现健康监测
yum install keepalived -y

# 备份keepalived原始文件
mv /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak

# 生成新的keepalived配置文件,文中注释部分对每台master请进行修改
cat < /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   router_id k8s-master1                      #主调度器的主机名
   vrrp_mcast_group4 224.26.1.1         

}

vrrp_instance VI_1 {
    state BACKUP                          
    interface eth0
    virtual_router_id 66              
    nopreempt                             
    priority 90                         
    advert_int 1
    authentication {
        auth_type PASS                     
        auth_pass 123456                 
    }
    virtual_ipaddress {
        10.20.1.8                            #VIP地址声明
    }
}
EOF

# 配置keepalived开机启动和启动keepalived
systemctl enable keepalived
systemctl start keepalived

生成kubeadm master 配置文件

cd && cat < kubeadm.yaml
apiVersion: kubeadm.k8s.io/v1beta1
kind: ClusterConfiguration
kubernetesVersion: stable
apiServer:
  certSANs:
  - "172.29.2.188"  #请求改为你的vip地址
controlPlaneEndpoint: "172.29.2.188:6443"  #请求改为你的vip地址
imageRepository: registry.cn-hangzhou.aliyuncs.com/peter1009
networking:
  dnsDomain: cluster.local
  podSubnet: "10.244.0.0/16"
  serviceSubnet: 10.96.0.0/12
EOF

初始化第一个master

# 使用上一步生成的kubeadm.yaml
kubeadm init --config kubeadm.yaml

# 执行完上一步输出如下
root@k8s4:~# kubeadm  init --config kubeadm.yaml
I0522 06:20:13.352644    2622 version.go:96] could not fetch a Kubernetes version from 
......... 此处省略
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/

You can now join any number of control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join 172.16.10.114:6443 --token v2lv3k.aysjlmg3ylcl3498 \
    --discovery-token-ca-cert-hash sha256:87b69e590e9d59055c5a9c6651e333044c402dba877beb29906eddfeb0998d72 \
    --experimental-control-plane

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

kubeadm join 172.16.10.114:6443 --token v2lv3k.aysjlmg3ylcl3498 \
    --discovery-token-ca-cert-hash sha256:87b69e590e9d59055c5a9c6651e333044c402dba877beb29906eddfeb0998d72

安装集群

cat < copy.sh
CONTROL_PLANE_IPS="172.16.10.101 172.16.10.102"  # 修改这两个ip地址为你第二/第三masterip地址
for host in ${CONTROL_PLANE_IPS}; do
    ssh $host mkdir -p /etc/kubernetes/pki/etcd
    scp /etc/kubernetes/pki/ca.crt "${USER}"@$host:/etc/kubernetes/pki/
    scp /etc/kubernetes/pki/ca.key "${USER}"@$host:/etc/kubernetes/pki/
    scp /etc/kubernetes/pki/sa.key "${USER}"@$host:/etc/kubernetes/pki/
    scp /etc/kubernetes/pki/sa.pub "${USER}"@$host:/etc/kubernetes/pki/
    scp /etc/kubernetes/pki/front-proxy-ca.crt "${USER}"@$host:/etc/kubernetes/pki/
    scp /etc/kubernetes/pki/front-proxy-ca.key "${USER}"@$host:/etc/kubernetes/pki/
    scp /etc/kubernetes/pki/etcd/ca.crt "${USER}"@$host:/etc/kubernetes/pki/etcd/ca.crt
    scp /etc/kubernetes/pki/etcd/ca.key "${USER}"@$host:/etc/kubernetes/pki/etcd/ca.key
    scp /etc/kubernetes/admin.conf "${USER}"@$host:/etc/kubernetes/
done
EOF

# 如果未配置免密登录,该步骤讲失败
bash -x copy.sh

# 在当前节点执行提示内容,使kubectl能访问集群
  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

# 在其他master节点上配置执行提示内容(必须要copy.sh文件执行成功以后)
kubeadm join 172.16.10.114:6443 --token v2lv3k.aysjlmg3ylcl3498 \
    --discovery-token-ca-cert-hash sha256:87b69e590e9d59055c5a9c6651e333044c402dba877beb29906eddfeb0998d72 \
    --experimental-control-plane

# 在其他非master的节点上配置执行提示内容
kubeadm join 172.16.10.114:6443 --token v2lv3k.aysjlmg3ylcl3498 \
    --discovery-token-ca-cert-hash sha256:87b69e590e9d59055c5a9c6651e333044c402dba877beb29906eddfeb0998d72

安装flannel

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

检查是否安装完成

root@k8s4:~# kubectl  get nodes
NAME   STATUS   ROLES    AGE   VERSION
k8s4   Ready    master   20m   v1.14.2
root@k8s4:~# kubectl  get nodes
NAME   STATUS   ROLES    AGE   VERSION
k8s4   Ready    master   20m   v1.14.2
root@k8s4:~# kubectl  get pods --all-namespaces
NAMESPACE     NAME                           READY   STATUS    RESTARTS   AGE
kube-system   coredns-8cc96f57d-cfr4j        1/1     Running   0          20m
kube-system   coredns-8cc96f57d-stcz6        1/1     Running   0          20m
kube-system   etcd-k8s4                      1/1     Running   0          19m
kube-system   kube-apiserver-k8s4            1/1     Running   0          19m
kube-system   kube-controller-manager-k8s4   1/1     Running   0          19m
kube-system   kube-flannel-ds-amd64-k4q6q    1/1     Running   0          50s
kube-system   kube-proxy-lhjsf               1/1     Running   0          20m
kube-system   kube-scheduler-k8s4            1/1     Running   0          19m

测试是否能正常使用集群

# 取消节点污点,使master能被正常调度, k8s4请更改为你自有集群的nodename
kubectl  taint node k8s4 node-role.kubernetes.io/master:NoSchedule-

# 创建nginx deploy
root@k8s4:~# kubectl  create deploy nginx --image nginx
deployment.apps/nginx created

root@k8s4:~# kubectl  get pods
NAME                     READY   STATUS    RESTARTS   AGE
nginx-65f88748fd-9sk6z   1/1     Running   0          2m44s

# 暴露nginx到集群外
root@k8s4:~# kubectl  expose deploy nginx --port=80 --type=NodePort
service/nginx exposed
root@k8s4:~# kubectl  get svc
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1                443/TCP        25m
nginx        NodePort    10.104.109.234           80:32129/TCP   5s
root@k8s4:~# curl 127.0.0.1:32129







Welcome to nginx!
If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.

For online documentation and support please refer to
nginx.org.

Commercial support is available at
nginx.com.

Thank you for using nginx.