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目录
kubeadm搭建kubernets-1.16.2
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kubeadm搭建kubernets-1.16.2

环境准备

节点规划

主机名 节点ip 角色 部署组件
k8s-master 10.200.51.36 master etcd, kube-apiserver, kube-controller-manager, kubectl, kubeadm, kubelet, kube-proxy, flannel
k8s-slave1 10.200.51.49 node kubectl, kubelet, kube-proxy, flannel
k8s-slave2 10.200.51.54 node kubectl, kubelet, kube-proxy, flannel

组件版本

组件 版本 说明
CentOS 7.7.1908
Kernel Linux 3.10.0-1062.9.1.el7.x86_64
etcd 3.3.15 使用容器方式部署,默认数据挂载到本地路径
coredns 1.6.2
kubeadm v1.16.2
kubectl v1.16.2
kubelet v1.16.2
kube-proxy v1.16.2
flannel v0.11.0

设置hosts解析

操作节点:所有节点(k8s-master,k8s-slave)均需执行

hostnamectl set-hostname k8s-master

添加hosts解析

cat >> /etc/hosts <<EOF
10.200.51.36 k8s-master
10.200.51.49 k8s-slave1
10.200.51.54 k8s-slave2
EOF

调整系统配置

  • 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

  • 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

安装docker

操作节点:matser、slave

  • 查看所有的可用版本
$ yum list docker-ce --showduplicates | sort -r
$ yum install docker-ce-18.09.9
  • 配置docker加速
[root@k8s-master ~]# cat /etc/docker/daemon.json 
{
  "insecure-registries": [    
    "10.200.51.36:5000" 
  ],
  "exec-opts": ["native.cgroupdriver=systemd"],                          
  "registry-mirrors" : [
    "https://dockerhub.azk8s.cn",
    "https://registry.docker-cn.com",
    "https://vtbf99sa.mirror.aliyuncs.com"
  ]
}
  • 启动docker
    systemctl enable docker && systemctl start docker

kubernets组建理解

理解集群资源

组件是为了支撑k8s平台的运行,安装好的软件。

资源是如何去使用k8s的能力的定义。比如,k8s可以使用Pod来管理业务应用,那么Pod就是k8s集群中的一类资源,集群中的所有资源可以提供如下方式查看:

$ kubectl api-resources

如何理解namespace:

命名空间,集群内一个虚拟的概念,类似于资源池的概念,一个池子里可以有各种资源类型,绝大多数的资源都必须属于某一个namespace。集群初始化安装好之后,会默认有如下几个namespace:

[root@k8s-master ~]# kubectl get namespace
NAME                   STATUS   AGE
default                Active   47h
kube-node-lease        Active   47h
kube-public            Active   47h
kube-system            Active   47h
kubernetes-dashboard   Active   46h
  • 所有NAMESPACED的资源,在创建的时候都需要指定namespace,若不指定,默认会在default命名空间下
  • 相同namespace下的同类资源不可以重名,不同类型的资源可以重名
  • 不同namespace下的同类资源可以重名
  • 通常在项目使用的时候,我们会创建带有业务含义的namespace来做逻辑上的整合

kubectl的使用

类似于docker,kubectl是命令行工具,用于与APIServer交互,内置了丰富的子命令,功能极其强大。 https://kubernetes.io/docs/reference/kubectl/overview/

$ kubectl -h
$ kubectl get -h
$ kubectl create -h
$ kubectl create namespace -h

kubectl如何管理集群资源
kubectl get po -v=7

安装k8s

所有节点安装:

$ yum install -y kubelet-1.16.2 kubeadm-1.16.2 kubectl-1.16.2 --disableexcludes=kubernetes
## 查看kubeadm 版本
$ kubeadm version
## 设置kubelet开机启动
$ systemctl enable kubelet

初始化配置文件

操作节点: 只在master节点(k8s-master)执行

$ kubeadm config print init-defaults > kubeadm.yaml
$ cat kubeadm.yaml
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 10.200.51.36  # 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: k8s-master  # 默认读取当前master节点的hostname
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
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: v1.16.2
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16    # Pod 网段,flannel插件需要使用这个网段
  serviceSubnet: 10.96.0.0/12
scheduler: {}

对于上面的资源清单的文档比较杂,要想完整了解上面的资源对象对应的属性,可以查看对应的 godoc 文档,地址: https://godoc.org/k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta2

下载镜像

操作节点:只在master节点(k8s-master)执行
#查看需要使用的镜像列表,若无问题,将得到如下列表:

[root@k8s-master ~]# kubeadm config images list --config kubeadm.yaml
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.16.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.16.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.16.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.16.2
registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.3.15-0
registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.2

#提前下载镜像到本地
kubeadm config images pull --config kubeadm.yaml

#查看使用的镜像源

[root@k8s-master ~]# kubeadm config images list --config kubeadm.yaml
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.16.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.16.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.16.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.16.2
registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.3.15-0
registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.2

初始化master节点

kubeadm init --config kubeadm.yaml

若初始化成功后,接下来按照提示信息操作,配置kubectl客户端的认证

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

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 192.168.51.209:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:f98a23b18ce654b63be45cabae9c6029bf8fded846b82c05a8f5d24b9a5627e6

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。

添加slave节点到集群中

操作节点:所有的slave节点(k8s-slave)需要执行
在每台slave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 10.200.51.36:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:1c4305f032f4bf534f628c32f5039084f4b103c922ff71b12a5f0f98d1ca9a4f

安装flannel网络插件

操作节点:只在master节点(k8s-master)执行

  • 下载flannel的yaml网络插件
wget https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml

修改配置,指定网卡名称,添加一行配置:

[root@k8s-master ~]# vim kube-flannel.yml

...
 containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.11.0-amd64
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        - --iface=ens33    # 如果机器存在多网卡的话,指定内网网卡的名称,默认不指定的话会找第一块网
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
...

先拉取镜像,此过程国内速度比较慢

$ docker pull quay.io/coreos/flannel:v0.11.0-amd64

执行flannel安装

$ kubectl create -f kube-flannel.yml

验证集群

[root@k8s-master ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    master   2d    v1.16.2
k8s-slave1   Ready    <none>   2d    v1.16.2
k8s-slave2   Ready    <none>   47h   v1.16.2

部署dashboard

推荐使用下面这种方式

$ wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta5/aio/deploy/recommended.yaml
$ vi recommended.yaml
# 修改Service为NodePort类型
---

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31600端口
[root@k8s-master ~]# kubectl -n kubernetes-dashboard get svc
NAME                        TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)         AGE
dashboard-metrics-scraper   ClusterIP   10.98.136.3    <none>        8000/TCP        46h
kubernetes-dashboard        NodePort    10.105.51.87   <none>        443:31600/TCP   46h

推荐用火狐浏览器打开:https://10.200.51.36

  • 创建ServiceAccount进行访问
[root@k8s-master ~]# cat admin.yaml 
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
[root@k8s-master ~]# kubectl create -f admin.yaml
[root@k8s-master ~]#  kubectl -n kubernetes-dashboard get secret |grep admin-token
admin-token-rxxdr                  kubernetes.io/service-account-token   3      46h
#使用该命令拿到token
[root@k8s-master ~]#  kubectl -n kubernetes-dashboard get secret admin-token-rxxdr -o jsonpath={.data.token}|base64 -d
eyJhbGciOiJSUzI1NiIsImtpZCI6IlFGT1ltSGp0S1RfckhVaW1XNV9qQVVxZ0t1TEk1WFUzbDN6U193N2tkbjAifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlcm5ldGVzLWRhc2hib2FyZCIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi10b2tlbi1yeHhkciIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50Lm5hbWUiOiJhZG1pbiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjU0NmIxMGY3LWJlNTItNGYzMC1iMDcwLTUyOTAxNmI2ZGRiYiIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDprdWJlcm5ldGVzLWRhc2hib2FyZDphZG1pbiJ9.Y0rX5hxebuJShcTMNPaMgCXicVSZtxcx31HoZhiB-_cFt8PAdU5GU8nGiGbvt2LW-iNqn_0E1RuuMwEsD26rfnClt23IPZpBriPEZ84fb4QQZurFsloCthM8R2YmPVy3owYN-Y-dEilsSnofhHpB2Z6oLKXHt0W7yNqUse7MSRlQNedosgpTP0E6AhL9z7GoE6l-M_SUuhR2gNc8jqo8EkG-06jOJB5DIi_SLzME4sAduqkRm4zDlJECortKvpfr02FEQ5UBwxquteqqQjyOAWo1K3tM8_fd_RMwWXCZAaaJLXgOXhDzAzkkDACx2XR0Ugzin3W_IAyVGqcCvleP2Q

然后浏览器访问:
image.png

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:

$ kubeadm reset
$ ifconfig cni0 down && ip link delete cni0
$ ifconfig flannel.1 down && ip link delete flannel.1
$ rm -rf /var/lib/cni/


标题:kubeadm搭建kubernets-1.16.2
作者:cuijianzhe
地址:https://cjzshilong.cn/articles/2020/04/10/1586510174363.html

到头来 我们记住的 不是敌人的攻击 而是朋友的沉默 ---马丁·路德·金


                    
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