kubeadm部署K8S集群（v1.14.2）

目录

• 1. 简介
• 2.节点规划
• 3.安装前准备工作
  • 3.1 设置hosts解析
  • 3.2调整系统配置
  • 3.3 安装docker
• 4. 部署kubernetes
  • 4.1 安装kubeadm，kubelet和kubectl
  • 4.2 初始化配置文件
  • 4.3 提前下载镜像
  • 4.4 初始化master节点
  • 4.5 添加node节点到集群中
  • 4.6 安装calico网络插件
  • 4.7 设置kubectl自动补全
• 5.部署dashboard
• 6. 清理环境

1. 简介

测试环境Kubernetes 1.14.2版本搭建文档，搭建方式为kubeadm

2.节点规划

部署k8s集群的节点按照用途可以划分为如下2类角色：

• master：集群的master节点，集群的初始化节点，基础配置不低于2C4G
• node：集群的node接点，可以多台，基础配置不低于2C4G

本次部署是一台master+2台node，节点规划如下：

主机名	节点ip	角色	部署组件
k8s-master	172.18.126.1	master	etcd, kube-apiserver, kube-controller-manager, kubectl, kubeadm, kubelet, kube-proxy, calico
k8s-node01	172.18.126.2	node	kubectl, kubelet, kube-proxy, calico
k8s-node02	172.18.126.3	node	kubectl, kubelet, kube-proxy, calico

3.安装前准备工作

3.1 设置hosts解析

操作节点：所有节点都需要执行

• 修改hostname

# 在master节点
$ hostnamectl set-hostname k8s-master #设置master节点的hostname

# 在slave-1节点
$ hostnamectl set-hostname k8s-slave1 #设置slave1节点的hostname

# 在slave-2节点
$ hostnamectl set-hostname k8s-slave2 #设置slave2节点的hostname

• 添加hosts解析

$ cat >>/etc/hosts<<EOF
172.18.126.1 master
172.18.126.2 node01
172.18.126.3 node02
EOF

3.2调整系统配置

操作节点：所有节点都需要执行

• 设置安全组开放端口

如果节点间无安全组限制（内网机器间可以任意访问），可以忽略，否则，至少保证如下端口可通：
k8s-master节点：TCP：6443，2379，2380，60080，60081UDP协议端口全部打开
k8s-slave节点：UDP协议端口全部打开

• 设置iptables

iptables -P FORWARD ACCEPT

• 关闭swap

swapoff -a
# 防止开机自动挂载 swap 分区
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

• 关闭selinux和防火墙

sed -ri 's#(SELINUX=).*#\1disabled#' /etc/selinux/config
setenforce 0
systemctl disable firewalld && systemctl stop firewalld

• 修改内核参数

cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward=1
vm.max_map_count=262144
EOF
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf  

• 设置yum源

$ curl -o /etc/yum.repos.d/Centos-7.repo http://mirrors.aliyun.com/repo/Centos-7.repo
$ curl -o /etc/yum.repos.d/docker-ce.repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
$ cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
$ yum clean all && yum makecache

3.3 安装docker

操作节点：所有节点均需操作

## 查看所有的可用版本
$ yum list docker-ce --showduplicates | sort -r
##安装旧版本 yum install docker-ce-cli-18.09.9-3.el7  docker-ce-18.09.9-3.el7
## 安装源里最新版本
$ yum install docker-ce-20.10.6 -y

## 配置docker加速
$ mkdir -p /etc/docker
vi /etc/docker/daemon.json
{
  "insecure-registries": [    
    "172.18.126.1:5000" 
  ],                          
  "registry-mirrors" : [
    "https://8xpk5wnt.mirror.aliyuncs.com"
  ]
}
## 启动docker
$ systemctl enable docker && systemctl start docker

4. 部署kubernetes

4.1 安装kubeadm，kubelet和kubectl

操作节点：所有节点均需执行

#首先安装kubelet-1.14.2，一起安装会报错（原因暂不知晓）
$ yum install -y kubelet-1.14.2
$ yum install -y  kubeadm-1.14.2 kubectl-1.14.2  ipvsadm

## 查看kubeadm 版本
$ kubeadm version
## 设置kubelet开机启动
$ systemctl enable kubelet 

4.2 初始化配置文件

操作节点：只在master节点执行
使用kubeadm config print init-defaults > kubeadm.yaml 打印出默认配置，然后在根据自己的环境修改配置

$ kubeadm config print init-defaults > kubeadm.yaml
$ cat kubeadm.yaml
apiVersion: kubeadm.k8s.io/v1beta1
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 1.2.3.4    #apiserver地址，因为单master，所以配置master的节点内网IP
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: master
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta1
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: ""
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers  ## 修改成阿里镜像源
kind: ClusterConfiguration
kubernetesVersion: v1.14.2 #修改成你安装的版本号
networking:
  dnsDomain: cluster.local
  podSubnet: ""
  serviceSubnet: 10.96.0.0/12
scheduler: {}

4.3 提前下载镜像

操作节点：只在master节点执行

$  kubeadm config images pull --config kubeadm.yaml
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.14.2
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.14.2
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.14.2
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.14.2
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.3.10
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.3.1

4.4 初始化master节点

操作节点：只在master节点执行

$ kubeadm init --config kubeadm.yaml

若初始化成功后，最后会提示如下信息：

...
Your Kubernetes master 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/

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

kubeadm join 172.18.126.1:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:1c4305f032f4bf534f628c32f5039084f4b103c922ff71b12a5f0f98d1ca9a4f

接下来按照上述提示信息操作，配置kubectl客户端的认证

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

⚠️注意：此时使用 kubectl get nodes查看节点应该处于notReady状态，因为还未配置网络插件
若执行初始化过程中出错，根据错误信息调整后，执行kubeadm reset后再次执行init操作即可

4.5 添加node节点到集群中

操作节点：所有的node节点需要执行
在每台node节点，执行如下命令，该命令是在kubeadm init成功后提示信息中打印出来的，需要替换成实际init后打印出的命令。

kubeadm join 172.18.126.1:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:1c4305f032f4bf534f628c32f5039084f4b103c922ff71b12a5f0f98d1ca9a4f

如果忘记添加命令，可以通过如下命令生成：

$ kubeadm token create --print-join-command

4.6 安装calico网络插件

操作节点：只在master节点执行

• 下载calico.yaml文件

wget -c https://docs.projectcalico.org/v3.6/getting-started/kubernetes/installation/hosted/kubernetes-datastore/calico-networking/1.7/calico.yaml

• 修改calico文件
  修改CALICO_IPV4POOL_CIDR这个下面的vaule值，默认是192.168.0.0/16，请与kubeadm-init.yaml文件中serviceSubnet字段值保持一致

# The default IPv4 pool to create on startup if none exists. Pod IPs will be
        # chosen from this range. Changing this value after installation will have
        # no effect. This should fall within `--cluster-cidr`.
        - name: CALICO_IPV4POOL_CIDR
          value: "10.96.0.0/12"

• 生成网络组件

kubectl apply -f calico.yaml

• 查看各个节点状态

$ kubectl get nodes
NAME       STATUS   ROLES    AGE   VERSION
master      Ready    master   85m   v1.14.2
node01     Ready    <none>   16m   v1.14.2
node02     Ready    <none>   16m   v1.14.2

4.7 设置kubectl自动补全

操作节点：master节点

$ yum install bash-completion -y
$ source /usr/share/bash-completion/bash_completion
$ source <(kubectl completion bash)
$ echo "source <(kubectl completion bash)" >> ~/.bashrc

5.部署dashboard

• 部署服务

# 推荐使用下面这种方式
$ wget  https://raw.githubusercontent.com/kubernetes/dashboard/v2.2.0/aio/deploy/recommended.yaml
$ vi recommended.yaml
# 修改Service为NodePort类型，文件的45行上下
......
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard
  type: NodePort  # 加上type=NodePort变成NodePort类型的服务
......

• 查看访问地址，本例为30997端口

$ kubectl apply -f recommended.yaml
$ kubectl -n kubernetes-dashboard get svc
NAME                        TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)         AGE
dashboard-metrics-scraper   ClusterIP   10.102.58.202    <none>        8000/TCP        22h
kubernetes-dashboard        NodePort    10.101.133.227   <none>        443:30997/TCP   22h

* 使用浏览器访问 https://172.21.51.143:30133，其中172.21.51.143为master节点的外网ip地址，chrome目前由于安全限制，测试访问不了，使用firefox可以进行访问。
* 创建ServiceAccount进行访问
```powershell
$ vi dashboard-admin.conf
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: admin
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io
subjects:
- kind: ServiceAccount
  name: admin
  namespace: kubernetes-dashboard

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin
  namespace: kubernetes-dashboard

$ kubectl apply -f dashboard-admin.conf
$ kubectl -n kubernetes-dashboard get secret |grep admin-token
admin-token-fqdpf                  kubernetes.io/service-account-token   3      7m17s
# 使用该命令拿到token，然后粘贴到浏览器中
$ kubectl -n kubernetes-dashboard get secret admin-token-fqdpf -o jsonpath={.data.token}|base64 -d
eyJhbGciOiJSUzI1NiIsImtpZCI6Ik1rb2xHWHMwbWFPMjJaRzhleGRqaExnVi1BLVNRc2txaEhETmVpRzlDeDQifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlcm5ldGVzLWRhc2hib2FyZCIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi10b2tlbi1mcWRwZiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50Lm5hbWUiOiJhZG1pbiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjYyNWMxNjJlLTQ1ZG...

6. 清理环境

如果你的集群安装过程中遇到了其他问题，我们可以使用下面的命令来进行重置：

# 在全部集群节点执行
kubeadm reset
ifconfig cni0 down && ip link delete cni0
ifconfig flannel.1 down && ip link delete flannel.1
rm -rf /run/flannel/subnet.env
rm -rf /var/lib/cni/
mv /etc/kubernetes/ /tmp
mv /var/lib/etcd /tmp
mv ~/.kube /tmp
iptables -F
iptables -t nat -F
ipvsadm -C
ip link del kube-ipvs0
ip link del dummy0