基于centos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(可选但建议)

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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

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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
  4. 允许 iptables 检查桥接流量
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cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
br_netfilter
EOF

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sudo sysctl --system

安装runtime

先决条件

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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

# 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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# 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

生成默认配置

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sudo mkdir -p /etc/containerd
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

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Docker

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curl -fsSL get.docker.com | bash

配置Doker

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sudo mkdir /etc/docker
cat <<EOF | sudo tee /etc/docker/daemon.json
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

sudo systemctl restart docker

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=0
repo_gpgcheck=0
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
exclude=kubelet kubeadm kubectl
EOF

# 将 SELinux 设置为 permissive 模式（相当于将其禁用）
sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

sudo yum install -y kubelet-1.21.10-0 kubeadm-1.21.10-0 kubectl-1.21.10-0 --disableexcludes=kubernetes

sudo systemctl enable --now kubelet
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# 创建仓库文件
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=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

setenforce 0

# 安装指定版本的kubeadm
yum install -y --nogpgcheck kubelet-1.21.10-0 kubeadm-1.21.10-0 kubectl-1.21.10-0

# 启动kubelet
systemctl enable --now kubelet

准备负载均衡

在public机器上执行，负载均衡软件选一个就行了，以下二选一

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yum install -y haproxy
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--- 前面保持默认配置 ---

frontend k8s_api_fe
    bind :6443
    default_backend k8s_api_be
    mode tcp
    option tcplog
backend k8s_api_be
    balance source
    mode tcp
    server      master1 master1:6443 check
    server      master2 master2:6443 check
    server      master3 master3:6443 check

frontend http_ingress_traffic_fe
    bind :80
    default_backend http_ingress_traffic_be
    mode tcp
    option tcplog
backend http_ingress_traffic_be
    balance source
    mode tcp
    server      worker1 10.0.0.21:30080 check   # 这里需要更改成ingress的NodePort
    server      worker2 10.0.0.22:30080 check   # 这里需要更改成ingress的NodePort

frontend https_ingress_traffic_fe
    bind *:443
    default_backend https_ingress_traffic_be
    mode tcp
    option tcplog
backend https_ingress_traffic_be
    balance source
    mode tcp
    server      worker1 10.0.0.21:30443 check   # 这里需要更改成ingress的NodePort
    server      worker2 10.0.0.22:30443 check   # 这里需要更改成ingress的NodePort

vim nginx.conf 在文件最后添加

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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

在init之前先将镜像拉取到本地（可选步骤）

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kubeadm config images pull --kubernetes-version 1.21.10

在k8s-master0上执行

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sudo kubeadm init \
--kubernetes-version 1.21.10 \
--control-plane-endpoint "kube-apiserver:6443" \
--upload-certs \
--service-cidr=10.96.0.0/12 \
--pod-network-cidr=10.244.0.0/16

在init之前先将镜像拉取到本地（可选步骤）

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kubeadm config images pull --kubernetes-version 1.21.10 --image-repository registry.cn-hangzhou.aliyuncs.com/google_containers

在k8s-master0上执行

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sudo kubeadm init \
--kubernetes-version 1.21.10 \
--control-plane-endpoint "kube-apiserver:6443" \
--image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
--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 后会输出在终端上, 有效期2小时, 超时后可以重新生成

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)"

移除节点

移除节点

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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