「掌握K8S集群」手把手真正实现Kubernetes集群的配置与部署

off999 2025-01-13 16:46 25 浏览 0 评论

1、环境准备

IP	HOSTNAME
10.10.20.15	k8s1
10.10.20.16	k8s2
10.10.20.17	k8s3

注意hostname不要用下划线、小数点与字母。

2、环境配置（所有节点）

# stop firewalld
systemctl stop firewalld
systemctl disable firewalld

# disable selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0

# disable sawp 
swapoff -a
sed -ri 's/.*swap.*/#&/' /etc/fstab 

# config route forward
cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
br_netfilter
EOF
echo 'net.ipv4.ip_forward = 1' >> /etc/sysctl.d/k8s.conf

# ipv6 config
echo 'net.bridge.bridge-nf-call-ip6tables = 1' >> /etc/sysctl.d/k8s.conf
echo 'net.bridge.bridge-nf-call-iptables = 1' >> /etc/sysctl.d/k8s.conf
echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.d/k8s.conf
echo "net.ipv6.conf.default.disable_ipv6 = 1" >> /etc/sysctl.d/k8s.conf
echo "net.ipv6.conf.lo.disable_ipv6 = 1" >> /etc/sysctl.d/k8s.conf
echo "net.ipv6.conf.all.forwarding = 1"  >> /etc/sysctl.d/k8s.conf
modprobe br_netfilter
sysctl --system

# config ipvs
cat <<EOF | sudo tee /etc/sysconfig/modules/ipvs.modules
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF
chmod 755 /etc/sysconfig/modules/ipvs.modules 
sh /etc/sysconfig/modules/ipvs.modules

# install ipvsadm
yum install -y ipset ipvsadm

3、安装Docker(所有节点)

# 删除系统自带docker组件
yum -y remove docker*
# 安装相关组件
yum -y install yum-utils
# 配置docker安装镜像源
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

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

# 这里安装的是20.10.2版本，需与kubernetes匹配一致
yum install -y docker-ce-20.10.2  docker-ce-cli-20.10.2 containerd.io

# 启动服务
systemctl start docker
systemctl enable docker

# 配置镜像加速, 修改cgroupdriver
vi  /etc/docker/daemon.json
{
  "registry-mirrors": [
    "https://registry.docker-cn.com",
    "http://hub-mirror.c.163.com",
    "https://docker.mirrors.ustc.edu.cn"
  ],
  "exec-opts": ["native.cgroupdriver=systemd"]
}

#重启服务
systemctl daemon-reload
systemctl restart docker

4、安装K8S服务（所有节点）

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

# 设置K8S的yum安装源
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

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

# 安装kubelet、kubeadm、kubectl, 这里安装的版本为1.23.0, 可以支持上面的20.10.2版本
yum install -y kubelet-1.23.0 kubeadm-1.23.0 kubectl-1.23.0

# 开机启动kubelet
systemctl enable kubelet
systemctl start kubelet

5、配置Master主节点(主节点)

1) 查看需要的镜像

[root@k8s1 ~]# kubeadm config images list
k8s.gcr.io/kube-apiserver:v1.23.14
k8s.gcr.io/kube-controller-manager:v1.23.14
k8s.gcr.io/kube-scheduler:v1.23.14
k8s.gcr.io/kube-proxy:v1.23.14
k8s.gcr.io/pause:3.6
k8s.gcr.io/etcd:3.5.1-0
k8s.gcr.io/coredns/coredns:v1.8.6

2) 下载镜像

# 创建脚本
vi images.sh
# 配置脚本内容
images=(
 kube-apiserver:v1.23.14
 kube-controller-manager:v1.23.14
 kube-scheduler:v1.23.14
 kube-proxy:v1.23.14
 pause:3.6
 etcd:3.5.1-0
 coredns:v1.8.6
 )
for imageName in ${images[@]} ; 
do
    docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
done

# 执行脚本
chmod +x images.sh && ./images.sh

如果需修改镜像标签，命令（默认情况下不需改，下面初始化命令会指定对应空间名称）：

docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName

3）主节点执行初始化命令

# 初始化节点的配置信息
kubeadm init \
--apiserver-advertise-address=10.10.20.15 \
--image-repository registry.aliyuncs.com/google_containers \
--kubernetes-version v1.23.0 \
--service-cidr=10.20.0.0/16 \
--pod-network-cidr=10.30.0.0/16

# --ignore-preflight-errors=Swap 参数可以忽略交换内存的提示错误

注意：如果出现问题，执行kubeadm reset进行还原。

如果出现初始化报错：

[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz": dial tcp 127.0.0.1:10248: connect: connection refused.

执行重置命令，再修改docker的cgroupdriver配置:

vi /etc/docker/daemon.json 

{
  "registry-mirrors": [
    "https://registry.docker-cn.com",
    "http://hub-mirror.c.163.com",
    "https://docker.mirrors.ustc.edu.cn"
  ],
  "exec-opts": ["native.cgroupdriver=systemd"]

}

重启docker:

systemctl daemon-reload
systemctl restart docker

初始化，执行成功后，会出现如下提示：

Your Kubernetes control-plane 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

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 10.10.20.15:16688 --token 6vmxut.lb3hvlxhux5suugx \
        --discovery-token-ca-cert-hash sha256:0f2b3e95ecee06bc40eca641548c3ca8afb86ebc2279f3fe2a75960330b0dbd1

4）主节点执行初始化配置

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



kubeadm join 10.10.20.15:16688 --token 6vmxut.lb3hvlxhux5suugx \
        --discovery-token-ca-cert-hash sha256:0f2b3e95ecee06bc40eca641548c3ca8afb86ebc2279f3fe2a75960330b0dbd1

5）安装helm插件

wget https://get.helm.sh/helm-v3.6.0-linux-amd64.tar.gz
tar -zxvf helm-v3.6.0-linux-amd64.tar.gz
mv linux-amd64/helm  /usr/local/bin/

执行helm list检查能否正确识别。

6）安装calico网络插件

下载tigera-operator插件，地址： https://github.com/projectcalico/calico/releases

wget https://github.com/projectcalico/calico/releases/download/v3.23.3/tigera-operator-v3.23.3.tgz

安装calico:

helm install calico tigera-operator-v3.23.3.tgz

检查确认相关的pod处于Running状态：

watch kubectl get pods -n calico-system

输出结果：

Every 2.0s: kubectl get pods -n calico-system                                                                                                                                       
NAME                                       READY   STATUS    RESTARTS   AGE
calico-kube-controllers-7bbdbd789c-jcvhz   1/1     Running   0          62m
calico-node-z6t9g                          1/1     Running   0          62m
calico-typha-9d5f49b9f-7xvw5               1/1     Running   0          62m

calico的api资源不建议采用kubectl来管理，安装calicoctl插件来管理：

wget https://github.com/projectcalico/calico/releases/download/v3.23.3/calicoctl-linux-amd64
mv calicoctl-linux-amd64 kubectl-calico
chmod +x kubectl-calico

验证插件是否正常：

kubectl calico -h

7) 验证k8s的dns

运行curl 容器

kubectl run curl --image=radial/busyboxplus:curl -it

查看curl状态， kubectl describe pod curl 如果出现错误不能调度：

Events:
  Type     Reason            Age                 From               Message
  ----     ------            ----                ----               -------
  Warning  FailedScheduling  38m                 default-scheduler  0/1 nodes are available: 1 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.
  Warning  FailedScheduling  23m (x14 over 37m)  default-scheduler  0/1 nodes are available: 1 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.

将master该为可调度：

 kubectl taint nodes --all node-role.kubernetes.io/master-

进入curl容器：

kubectl exec -it curl /bin/sh

进行解析，输出一下结果，确认正常：

[ root@curl:/ ]$ nslookup kubernetes.default
Server:    10.20.0.10
Address 1: 10.20.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes.default
Address 1: 10.20.0.1 kubernetes.default.svc.cluster.local

6、部署一个Nginx应用服务

kubectl create deployment my-nginx --image=nginx

查看IP地址：

[root@k8s1 bin]# kubectl get pod -owide
NAME                               READY   STATUS    RESTARTS       AGE     IP              NODE   NOMINATED NODE   READINESS GATES
curl                               1/1     Running   0              121m    10.30.166.198   k8s1   <none>           <none>
my-nginx-c54945c55-lhmlt           1/1     Running   0              8m27s   10.30.219.1     k8s3   <none>           <none>
tigera-operator-56d4765449-tw7bv   1/1     Running   1 (136m ago)   140m    10.10.20.15     k8s1   <none>           <none>

进行访问：

[root@k8s1 bin]# curl 10.30.219.1
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

应用服务部署成功，可以正常访问。

选择对应的calico版本，确定能够支持所安装kubernetes

查看地址： https://projectcalico.docs.tigera.io/archive/v3.23/getting-started/kubernetes/requirements

执行命令：

kubectl apply -f https://projectcalico.docs.tigera.io/archive/v3.23/manifests/tigera-operator.yaml
kubectl apply -f https://projectcalico.docs.tigera.io/archive/v3.23/manifests/custom-resources.yaml

7、部署Dashboard管理后台

下载配置文件：

wget  https://raw.githubusercontent.com/kubernetes/dashboard/v2.5.0/aio/deploy/recommended.yaml

对外暴露，修改recommended.yaml文件：

增加type: NodePort

...
spec:
  ports:
    - port: 443
      targetPort: 8443
  type: NodePort
...

执行： kubectl get svc -A 查看dashboard的对外访问端口：

chrome浏览器进行访问：

如果不能访问，点击页面任意空白位置，盲敲：thisisunsafe 确认即可访问。

配置dashboard-config.yaml:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: kubernetes-dashboard
  namespace: kube-system
  annotations:
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
  ingressClassName: nginx
  tls:
  - hosts:
    - k8s.example.com
    secretName: example-com-tls-secret
  rules:
  - host: k8s.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
           name: kubernetes-dashboard
           port:
             number: 443

创建管理员：

kubectl create serviceaccount kube-dashboard-admin-sa -n kube-system

kubectl create clusterrolebinding kube-dashboard-admin-sa \
--clusterrole=cluster-admin --serviceaccount=kube-system:kube-dashboard-admin-sa

获取登录token:

[root@k8s1 ~]# kubectl -n kube-system get secret | grep kube-dashboard-admin-sa-token
kube-dashboard-admin-sa-token-jtfxk              kubernetes.io/service-account-token   3      78s

执行describe指令获取

[root@k8s1 ~]# kubectl describe -n kube-system secret/kube-dashboard-admin-sa-token-jtfxk
Name:         kube-dashboard-admin-sa-token-jtfxk
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: kube-dashboard-admin-sa
              kubernetes.io/service-account.uid: 85dabe0c-dd93-457e-b077-6c732e72a009

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1099 bytes
namespace:  11 bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IlBJV1FfTDN2ZWNIUTBMWVU2NGJ0WnRTVzF6QVNjZXlNWDNuY1o4S3B0V2MifQ.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.YPke1H3fdH_Vmw2980e-Kn2yRWklcvOt3o9ryfedmD5SLR_lkkUZb996SwZPb0mxReZi7Gjws5JdDYKnskIgvTTp8encsQ2UpLiC0myyzPUg6KP_3IHiTJ52n40mFNaZ7BzdyyYizatDWB89LruE2QrhEXdgOFxe-Z1GvzMdUpeAzrhV_a_bfE5iCkWmiw1jmaVba3X_MLiDoVPdUsQRovk6oZCNAzs9ElS0Hvb-vt4Ye6zI68Z0q3An36QFRk1CIE2RZfysq92QRSKgvRf8SgKN1UqyGFr9ICQcZTeiL0wNFGk04t6Z83RTK5n0BzojTrZwT-r0OGJb5coBJIkLPA

通过token进行登录，可以看到，能够正确显示集群信息：

nginx yii