Kubernetes节点上线和下线、Kubernetes高可用集群搭建上、Kubernetes高可用集群搭建中和Kubernetes高可用集群搭建下

一、Kubernetes节点上线和下线

1.新节点上线

1）准备工作
关闭防火墙firewalld、selinux
设置主机名
设置/etc/hosts
关闭swap

swapoff -a

永久关闭，vi /etc/fstab 注释掉swap那行

将桥接的ipv4流量传递到iptables链

modprobe br_netfilter ##生成bridge相关内核参数
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

打开端口转发

echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf
sysctl -p

时间同步

yum install -y chrony;
systemctl start chronyd;
systemctl enable chronyd

2）安装containerd
先安装yum-utils工具

yum install -y yum-utils

配置Docker官方的yum仓库，如果做过，可以跳过

yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo

安装containerd

yum install containerd.io -y

 启动服务

systemctl enable containerd
systemctl start containerd

生成默认配置

containerd config default > /etc/containerd/config.toml 

修改配置

vi /etc/containerd/config.toml
sandbox_image = "registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.9" # 修改为阿里云镜像地址
SystemdCgroup = true # 使用
systemd cgroup

重启containerd服务

systemctl restart containerd

3）配置kubernetes仓库

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

说明：kubernetes用的是RHEL7的源，和8是通用的

4）安装kubeadm和kubelet

yum install -y kubelet-1.27.2 kubeadm-1.27.2 kubectl-1.27.2

启动kubelet服务

systemctl start kubelet.service
systemctl enable kubelet.service 

 5）设置crictl连接 containerd

crictl config --set runtime-endpoint=unix:///run/containerd/containerd.sock

6）到master节点上，获取join token

kubeadm token create --print-join-command

7）到新节点，加入集群

kubeadm join 192.168.222.101:6443 --token uzopz7.ryng3lkdh2qwvy89 --discovery-token-cacert-hash sha256:1a1fca6d1ffccb4f48322d706ea43ea7b3ef2194483699952178950b52fe2601

8）master上查看node信息

kubectl get node

2. 节点下线

1）下线之前，先创建一个测试Deployment

命令行创建deployment，指定Pod副本为7
kubectl create deployment testdp2 --image=nginx:1.23.2 --replicas=7

查看Pod

kubectl get po -o wide

2）驱逐下线节点上的Pod，并设置不可调度（aminglinux01上执行）

kubectl drain aminglinux04 --ignore-daemonsets

3）恢复可调度（aminglinux01上执行）

kubectl uncordon aminglinux04

4）移除节点

kubectl delete node aminglinux04

二、Kubernetes高可用集群搭建（堆叠etcd模式）

 

堆叠etcd集群指的是，etcd和Kubernetes其它组件共用一台主机。

高可用思路：
1）使用keepalived+haproxy实现高可用+负载均衡
2）apiserver、Controller-manager、scheduler三台机器分别部署一个节点，共三个节点
3）etcd三台机器三个节点实现集群模式
机器准备（操作系统Rocky8.7）：
 

主机名	IP	安装组件
k8s-master01	192.168.100.11	etcd、apiserver、Controller-manager、scheduller、 keepalived、haproxy、kubelet、containerd、kubeadm
k8s-master02	192.168.100.12	etcd、apiserver、Controller-manager、scheduller、 keepalived、haproxy、kubelet、containerd、kubeadm
k8s-master03	192.168.100.13	etcd、apiserver、Controller-manager、scheduller、 keepalived、haproxy、kubelet、containerd、kubeadm
k8s-node01	192.168.100.14	kubelet、containerd、kubeadm
k8s-node01	192.168.100.15	kubelet、containerd、kubeadm
--	192.168.100.200

1.准备工作

说明：5台机器都做

1）关闭防火墙firewalld、selinux

[root@bogon ~]# sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
[root@bogon ~]# systemctl disable firewalld;  systemctl stop firewalld
Removed /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.

2）设置主机名

hostnamectl  set-hostname k8s-master01

3）设置/etc/hosts

echo "192.168.100.11  k8s-master01" >> /etc/hosts
echo "192.168.100.12  k8s-master01" >> /etc/hosts
echo "192.168.100.13  k8s-master01" >> /etc/hosts
echo "192.168.100.14  k8s-node01" >> /etc/hosts
echo "192.168.100.15  k8s-node02" >> /etc/hosts

4）关闭swap
swapoff -a
永久关闭， 注释掉swap那行

/dev/mapper/rl-root     /                       xfs     defaults        0 0
UUID=784fb296-c00c-4615-a4a6-583ae0156b04 /boot                   xfs     defaults        0 0
#/dev/mapper/rl-swap     none                    swap    defaults        0 0

5）将桥接的ipv4流量传递到iptables链

modprobe br_netfilter ##生成bridge相关内核参数
[root@bogon ~]# cat > /etc/sysctl.d/k8s.conf << EOF
> net.bridge.bridge-nf-call-ip6tables = 1
> net.bridge.bridge-nf-call-iptables = 1
> net.ipv4.ip_forward = 1
> EOF
sysctl --system # 生效

[root@bogon ~]# sysctl --system 
* Applying /usr/lib/sysctl.d/10-default-yama-scope.conf ...
kernel.yama.ptrace_scope = 0
* Applying /usr/lib/sysctl.d/50-coredump.conf ...
kernel.core_pattern = |/usr/lib/systemd/systemd-coredump %P %u %g %