基于AlmaLinux9使用kubeadm搭建集群， ubuntu部署文档, 有疑问的地方可以看官方文档

准备机器

我的机器详情如下, 配置至少为4C4G

hostname IP 作用
public 10.0.0.3 ingress和apiserver的负载均衡，nfs存储
master1 10.0.0.11 k8s master节点
master2 10.0.0.12 k8s master节点
master3 10.0.0.13 k8s master节点
worker1 10.0.0.21 k8s worker节点
worker2 10.0.0.22 k8s worker节点

每台机器都做域名解析，或者绑定hosts（直接使用ip地址会有警告）

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vim /etc/hosts

10.0.0.3  public kube-apiserver
10.0.0.11 master1
10.0.0.12 master2
10.0.0.13 master3

每台机器都关闭防火墙和SELinux

负载均衡机器必须要关闭,因为6443不是nginx的标准端口,会被selinux拦截, 防火墙也需要放行6443端口, 可以考虑直接关闭防火墙

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sudo systemctl disable --now firewalld
setenforce 0
sed -i "s/^SELINUX=.*/SELINUX=disabled/g" /etc/selinux/config

基础环境配置

基础环境是不管master还是worker都需要的环境

  1. 禁用swap
  2. 确保每个节点上 MAC 地址和 product_uuid 的唯一性sudo cat /sys/class/dmi/id/product_uuid
  3. 修改hostname

安装runtime

先决条件

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# 设置必需的 sysctl 参数，这些参数在重新启动后仍然存在。
cat <<EOF | sudo tee /etc/sysctl.d/99-kubernetes-cri.conf
net.bridge.bridge-nf-call-iptables  = 1
net.ipv4.ip_forward                 = 1
net.bridge.bridge-nf-call-ip6tables = 1
EOF

# 应用 sysctl 参数而无需重新启动
sudo sysctl --system

安装

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cat <<EOF | sudo tee /etc/modules-load.d/containerd.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter


# 卸载旧版本Docker
sudo yum remove docker \
              docker-client \
              docker-client-latest \
              docker-common \
              docker-latest \
              docker-latest-logrotate \
              docker-logrotate \
              docker-engine

# 安装docker仓库
sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

# 安装containerd
sudo yum install containerd.io -y

配置

从yum源安装的containerd默认禁用了cri，可以使用命令重新生成默认配置

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containerd config default | sudo tee /etc/containerd/config.toml

结合 runc 使用 systemd cgroup 驱动，在 /etc/containerd/config.toml 中设置

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[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
...
[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
   SystemdCgroup = true

配置registry.mirrors为阿里云镜像

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[plugins."io.containerd.grpc.v1.cri".registry.mirrors]
  [plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]      
    endpoint = ["https://bqr1dr1n.mirror.aliyuncs.com"]      
  [plugins."io.containerd.grpc.v1.cri".registry.mirrors."k8s.gcr.io"]      
    endpoint = ["https://registry.aliyuncs.com/k8sxio"] 

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sudo systemctl enable containerd
sudo systemctl restart containerd

crictl 配置

之前使用docker的时候，docker给我们做了很多好用的工具，现在用了containerd，管理容器我们用cri管理工具crictl，创建配置文件

vim /etc/crictl.yaml

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runtime-endpoint: unix:///run/containerd/containerd.sock
debug: false

安装kubeadm、kubelet 和 kubectl

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cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-\$basearch
enabled=1
gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
exclude=kubelet kubeadm kubectl
EOF

# 查看可用的版本
yum list kubelet kubeadm kubectl  --showduplicates --disableexcludes=kubernetes

sudo yum install -y kubelet-1.26.9-0 kubeadm-1.26.9-0 kubectl-1.26.9-0 --disableexcludes=kubernetes

sudo systemctl enable --now kubelet

准备负载均衡

在public机器上执行

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dnf install -y nginx nginx-all-modules

vim nginx.conf

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# 将server块监听80端口这一段删除
    server {
        listen       80;
        listen       [::]:80;
        server_name  _;
        root         /usr/share/nginx/html;

        # Load configuration files for the default server block.
        include /etc/nginx/default.d/*.conf;

        error_page 404 /404.html;
        location = /404.html {
        }

        error_page 500 502 503 504 /50x.html;
        location = /50x.html {
        }
    }


# 在文件最后添加
stream {
    include stream.conf;
}

然后vim /etc/nginx/stream.conf

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upstream k8s-apiserver {
    server master1:6443;
    server master2:6443;
    server master3:6443;
}
server {
    listen 6443;
    proxy_connect_timeout 1s;
    proxy_pass k8s-apiserver;
}
upstream ingress-http {
    server 10.0.0.21:30080;   # 这里需要更改成ingress的NodePort
    server 10.0.0.22:30080;   # 这里需要更改成ingress的NodePort
}
server {
    listen 80;
    proxy_connect_timeout 1s;
    proxy_pass ingress-http;
}
upstream ingress-https {
    server 10.0.0.21:30443;   # 这里需要更改成ingress的NodePort
    server 10.0.0.22:30443;   # 这里需要更改成ingress的NodePort
}
server {
    listen 443;
    proxy_connect_timeout 1s;
    proxy_pass ingress-https;
}

创建集群

kubeadm init

####创建初始化kubeadm文件

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kubeadm config print init-defaults > kubeadm-config.yaml

####创建的yaml文件

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apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 172.31.23.101 #高可用nginx-vip地址
  bindPort: 6443
nodeRegistration:
  criSocket: unix:///var/run/containerd/containerd.sock
  imagePullPolicy: IfNotPresent
  name: node
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns: {}
etcd:
  local:
    dataDir: /var/lib/etcd
# 修改镜像仓库地址
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: 1.28.0
networking:
  dnsDomain: cluster.local
  serviceSubnet: 10.96.0.0/12
  podSubnet: 10.244.0.0/16
scheduler: {}
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
cgroupDriver: systemd

在master1上执行

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sudo kubeadm init \
--kubernetes-version 1.26.9 \
--control-plane-endpoint "kube-apiserver:6443" \
--upload-certs \
--service-cidr=10.96.0.0/12 \
--pod-network-cidr=10.244.0.0/16

也可以用kubeadm config print init-defaults > init.yaml 生成kubeadm的配置，并用
kubeadm init --config=init.yaml来创建集群。

安装网络插件

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

获取join命令, 增加新的节点

node

kubeadm init 后会把加入master节点和加入worker节点的命令输出在终端上, 有效期2小时, 如果超时，可以重新生成

生成添加命令:

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kubeadm token create --print-join-command

master

  1. 生成证书, 记录certificate key

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    kubeadm init phase upload-certs --upload-certs

  2. 获取加入命令

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    kubeadm token create --print-join-command

  3. 上面两步可以简化成

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    echo "$(kubeadm token create --print-join-command) --control-plane --certificate-key $(kubeadm init phase upload-certs --upload-certs | tail -1)"

常见问题

常见问题

修改kube-proxy代理模式

相比iptables，使用ipvs可以提供更好的性能

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kubectl -n kube-system edit configmap kube-proxy

mode参数修改成ipvs

image.png

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kubectl -n kube-system rollout restart daemonset kube-proxy

查看kube-proxy日志，出现 Using ipvs Proxier 说明修改成功。
image.png

如何移除节点

移除worker节点

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kubectl drain worker2 --ignore-daemonsets
kubectl delete node worker2

如果是master节点还需要移除etcd member

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kubectl exec -it -n kube-system etcd-master1 -- /bin/sh

# 查看etcd member list
etcdctl --endpoints 127.0.0.1:2379 --cacert /etc/kubernetes/pki/etcd/ca.crt --cert /etc/kubernetes/pki/etcd/server.crt --key /etc/kubernetes/pki/etcd/server.key member list

# 通过ID来删除etcd member
etcdctl --endpoints 127.0.0.1:2379 --cacert /etc/kubernetes/pki/etcd/ca.crt --cert /etc/kubernetes/pki/etcd/server.crt --key /etc/kubernetes/pki/etcd/server.key member remove 12637f5ec2bd02b8