### 1. 安装前的准备工作

```sh
# 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld

# 查看hostname并修改

hostname   # 查看本机hostname
hostnamectl set-hostname k8s-master # 把本机名设置成k8s-master
hostnamectl status  # 查看修改结果
echo "127.0.0.1 $(hostname)" >> /etc/hosts  # 修改hosts文件

# 关闭selinux(linux的安全机制)
sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0

# 关闭swap(关闭内存交换)
swapoff -a
sed -ri 's/.*swap.*/#&/' '/etc/fstab'
free -m  # 检查，确保swap里面没有东西

# 配置桥接流量
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

# 生效
sudo sysctl --system
```

### 2. docker安装

省略。。。。

### 3. 安装k8s

```sh
# 配置k8s的yum源
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
gpg_key=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

#  卸载旧版本
yum remove -y kubelet kubeadm kubectl

# 查看可以安装的版本
yum list kubelet --showduplicates | sort -r   

# 安装kubernetes
yum install -y kubelet kubeadm kubectl

# 设置开机启动kubelet
systemctl enable kubelet

# 启动kubelet
systemctl start kubelet

# 查看kubelet状态
systemctl status kubelet  # kubelet进入无限死循环状态
```

>  如果执行安装kubelet失败。可能是我阿里云的yum源配置有问题，我联系了阿里云的售后，他帮我解决了。

### 4. 配置master节点

```sh
# 查看kubeadm需要下载的镜像
kubeadm config images list

## 需要下载的镜像
k8s.gcr.io/kube-apiserver:v1.23.1
k8s.gcr.io/kube-controller-manager:v1.23.1
k8s.gcr.io/kube-scheduler:v1.23.1
k8s.gcr.io/kube-proxy:v1.23.1
k8s.gcr.io/pause:3.6
k8s.gcr.io/etcd:3.5.1-0
k8s.gcr.io/coredns/coredns:v1.8.6

# 挨个下载以上镜像，由于是国外镜像，使用阿里云镜像仓库下载
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.23.1
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.23.1
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.23.1
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.23.1
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.6
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.5.1-0
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:v1.8.6

# 因为coredns是带二级目录的，所以要多执行这一步
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:v1.8.6 registry.cn-hangzhou.aliyuncs.com/google_containers/coredns/coredns:v1.8.6

# 创建k8s集群

# 查看eth0的inet私有网络地址，复制出来填入apiserver-advertise-address
ip a

# 初始化一个master节点
# image-respository  镜像仓库的地址
# service-cidr pod-network-cidr 设定两个子网范围，不能和apiserver冲突
kubeadm init \
--apiserver-advertise-address=172.31.43.126  \
--image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
--kubernetes-version v1.23.1 \
--service-cidr=172.100.0.0/16 \
--pod-network-cidr=192.168.0.0/16 \
--ignore-preflight-errors=all
```

* 巨坑：出现错误kubelet连接失败
```sh
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz": dial tcp [::1]:10248: connect: connection refused.

        Unfortunately, an error has occurred:
                timed out waiting for the condition

        This error is likely caused by:
                - The kubelet is not running
                - The kubelet is unhealthy due to a misconfiguration of the node in some way (required cgroups disabled)

        If you are on a systemd-powered system, you can try to troubleshoot the error with the following commands:
                - 'systemctl status kubelet'
                - 'journalctl -xeu kubelet'

        Additionally, a control plane component may have crashed or exited when started by the container runtime.
        To troubleshoot, list all containers using your preferred container runtimes CLI.

        Here is one example how you may list all Kubernetes containers running in docker:
                - 'docker ps -a | grep kube | grep -v pause'
                Once you have found the failing container, you can inspect its logs with:
                - 'docker logs CONTAINERID'

error execution phase wait-control-plane: couldn't initialize a Kubernetes cluster
To see the stack trace of this error execute with --v=5 or higher
```

> 产生原因：docker和kublelt的Cgroup Driver两个不一致

* 解决方法：
```sh
sudo docker info|grep Cgroup # 查看docker的 Cgroup Driver，显示为cgroupfs，而kubelet为systemd
vim /etc/docker/daemon.json # 加入"exec-opts": ["native.cgroupdriver=systemd"]
systemctl daemon-reload
systemctl restart docker
systemctl restart kubelet
```
执行成功显示如下：
```sh
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

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

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/

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

kubeadm join 172.31.43.126:6443 --token y5nwzd.kegm5jldmaep9i7z \
        --discovery-token-ca-cert-hash sha256:f14ca1c0c3321d4c1ee7386eab8df759c34808ac0f902619fee4c506adcf6d9d 
```

根据提示执行
```sh
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
export KUBECONFIG=/etc/kubernetes/admin.conf

# 并且安装插件，我这里安装Calico
kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

# 命令检查，获取集群中所有部署好的应用，等待他们都是running状态
kubectl get pod -A

# 查看集群里面所有的节点
kubectl get nodes
```