入门-k8s集群环境搭建（二）

对于 Kubernetes 初学者，在搭建K8S集群时，推荐在阿里云或腾讯云采购如下配置：（您也可以使用自己的虚拟机、私有云等您最容易获得的 Linux 环境）

• 至少2台 2核4G 的服务器
• Cent OS 7.6

 1. 检查 centos / hostname

# 在 master 节点和 worker 节点都要执行
cat /etc/redhat-release

# 此处 hostname 的输出将会是该机器在 Kubernetes 集群中的节点名字
# 不能使用 localhost 作为节点的名字
hostname

# 请使用 lscpu 命令，核对 CPU 信息
# Architecture: x86_64    本安装文档不支持 arm 架构
# CPU(s):       2         CPU 内核数量不能低于 2
lscpu

 2. 修改 hostname

# 修改 hostname
hostnamectl set-hostname your-new-host-name
# 查看修改结果
hostnamectl status
# 设置 hostname 解析
echo "127.0.0.1   $(hostname)" >> /etc/hosts

3. 检查网络

[root@guanbin-k8s-master ~]# ip route show
default via 192.168.85.1 dev ens160
blackhole 10.100.110.64/26 proto bird
10.100.110.65 dev cali055187aeadb scope link
10.100.110.66 dev cali84c4725d535 scope link
10.100.110.67 dev cali5ed802dd6c6 scope link
169.254.0.0/16 dev ens160 scope link metric 1002
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1
192.168.85.0/24 dev ens160 proto kernel scope link src 192.168.85.163

[root@guanbin-k8s-master ~]# ip address
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:50:56:98:55:c5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.85.163/24 brd 192.168.85.255 scope global ens160
       valid_lft forever preferred_lft forever
    inet6 fe80::250:56ff:fe98:55c5/64 scope link
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether 02:42:d0:41:25:02 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 scope global docker0
       valid_lft forever preferred_lft forever
4: cali055187aeadb@if3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1440 qdisc noqueue state UP group default
    link/ether ee:ee:ee:ee:ee:ee brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::ecee:eeff:feee:eeee/64 scope link
       valid_lft forever preferred_lft forever
5: tunl0@NONE: <NOARP,UP,LOWER_UP> mtu 1440 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ipip 0.0.0.0 brd 0.0.0.0
    inet 10.100.110.64/32 brd 10.100.110.64 scope global tunl0
       valid_lft forever preferred_lft forever
6: cali84c4725d535@if4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1440 qdisc noqueue state UP group default
    link/ether ee:ee:ee:ee:ee:ee brd ff:ff:ff:ff:ff:ff link-netnsid 1
    inet6 fe80::ecee:eeff:feee:eeee/64 scope link
       valid_lft forever preferred_lft forever
7: cali5ed802dd6c6@if4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1440 qdisc noqueue state UP group default
    link/ether ee:ee:ee:ee:ee:ee brd ff:ff:ff:ff:ff:ff link-netnsid 2
    inet6 fe80::ecee:eeff:feee:eeee/64 scope link
       valid_lft forever preferred_lft forever

kubelet使用的IP地址

• ip route show 命令中，可以知道机器的默认网卡，通常是 eth0，如 default via 172.21.0.23 dev eth0
• ip address 命令中，可显示默认网卡的 IP 地址，Kubernetes 将使用此 IP 地址与集群内的其他节点通信，如 172.17.216.80
• 所有节点上 Kubernetes 所使用的 IP 地址必须可以互通（无需 NAT 映射、无安全组或防火墙隔离）

4.关闭防火墙及selinux

 2个节点都操作

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

5.关闭分区

swapoff -a # 临时

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

6. 添加hosts

在所有主机上上添加如下命令

cat >> /etc/hosts << EOF 192.168.85.163 guanbin-k8s-master 192.168.12.38 guanbin-k8s-node EOF

7.设置系统时区并同步时间服务器

# yum install -y ntpdate

# ntpdate time.windows.com

8.安装docker (所有节点)

$ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
$ yum -y install docker-ce-18.06.1.ce-3.el7
$ systemctl enable docker && systemctl start docker
$ docker --version
Docker version 18.06.1-ce, build e68fc7a 

9. 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

10.安装kubeadm,kubelet和kubectl （所有主机）

$ yum install -y kubelet-1.15.0 kubeadm-1.15.0 kubectl-1.15.0
$ systemctl enable kubelet

11.部署k8s master

# 只在 master 节点执行
# 替换 x.x.x.x 为 master 节点实际 IP（请使用内网 IP）
# export 命令只在当前 shell 会话中有效，开启新的 shell 窗口后，如果要继续安装过程，请重新执行此处的 export 命令
export MASTER_IP=x.x.x.x
# 替换 apiserver.demo 为 您想要的 dnsName
export APISERVER_NAME=apiserver.demo
# Kubernetes 容器组所在的网段，该网段安装完成后，由 kubernetes 创建，事先并不存在于您的物理网络中
export POD_SUBNET=10.100.0.1/16
echo "${MASTER_IP}    ${APISERVER_NAME}" >> /etc/hosts
curl -sSL https://kuboard.cn/install-script/v1.18.x/init_master.sh | sh -s 1.18.0
 

输出日志为：

[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/

12.执行日志提示的命令

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

13.检查 master 初始化结果

# 只在 master 节点执行

# 执行如下命令，等待 3-10 分钟，直到所有的容器组处于 Running 状态
watch kubectl get pod -n kube-system -o wide

# 查看 master 节点初始化结果
kubectl get nodes -o wide

14.添加 node节点

 在master节点执行,可获取kubeadm join 命令及参数

# 只在 master 节点执行 kubeadm token create --print-join-command

 输出如下所示：

 该 token 的有效时间为 2 个小时，2小时内，您可以使用此 token 初始化任意数量的 worker 节点。

kubeadm join apiserver.demo:6443 --token mpfjma.4vjjg8flqihor4vt     --discovery-token-ca-cert-hash sha256:6f7a8e40a810323672de5eee6f4d19aa2dbdb38411845a1bf5dd63485c43d303

 在node节点执行上面的输出命令即可：

# 只在 worker 节点执行
# 替换 x.x.x.x 为 master 节点的内网 IP
export MASTER_IP=x.x.x.x
# 替换 apiserver.demo 为初始化 master 节点时所使用的 APISERVER_NAME
export APISERVER_NAME=apiserver.demo
echo "${MASTER_IP}    ${APISERVER_NAME}" >> /etc/hosts

# 替换为 master 节点上 kubeadm token create 命令的输出
kubeadm join apiserver.demo:6443 --token mpfjma.4vjjg8flqihor4vt     --discovery-token-ca-cert-hash sha256:6f7a8e40a810323672de5eee6f4d19aa2dbdb38411845a1bf5dd63485c43d303    

15.查看添加唉node节点是否成功

[root@guanbin-k8s-master ~]# kubectl get nodes
NAME                 STATUS   ROLES    AGE   VERSION
guanbin-k8s-master   Ready    master   59m   v1.18.0
guanbin-k8s-node     Ready    <none>   36m   v1.18.0

 注意：status是Ready说明已经成功了，若非Ready则执行以下命令查看原因：

kubectl describe node k8s-master | grep Ready

参考：https://kuboard.cn/install/install-k8s.html#%E5%AE%89%E8%A3%85-ingress-controller