kubernetes集群部署

K8S集群部署

kubeadm是官方社区推出的一个用于快速部署kubernetes集群的工具。

这个工具能通过两条指令完成一个kubernetes集群的部署：

# 创建一个 Master 节点
$ kubeadm init

# 将一个 Node 节点加入到当前集群中
$ kubeadm join 

官网：Kubernetes

官方文档：Kubernetes Documentation |Kubernetes

准备开始

• 一台兼容的 Linux 主机。Kubernetes 项目为基于 Debian 和 Red Hat 的 Linux 发行版以及一些不提供包管理器的发行版提供通用的指令
• 每台机器 2 GB 或更多的 RAM （如果少于这个数字将会影响你应用的运行内存)
• 2 CPU 核或更多
• 集群中的所有机器的网络彼此均能相互连接(公网和内网都可以)
• 节点之中不可以有重复的主机名、MAC 地址或 product_uuid。请参见这里了解更多详细信息。
• 开启机器上的某些端口。请参见这里 了解更多详细信息。
• 禁用交换分区。为了保证 kubelet 正常工作，你 必须 禁用交换分区。

1.准备环境

角色	IP
master	192.168.10.201
node1	192.168.10.202
node2	192.168.10.203

2.准备工作

在所有主机上执行：

关闭防火墙：
# systemctl disable --now firewalld

关闭selinux：
# sed -i 's/enforcing/disabled/' /etc/selinux/config

关闭swap：
# vim /etc/fstab
//注释或删除swap的行 
#/dev/mapper/cs-swap     none                    swap    defaults        0 0

设置主机名：
# hostnamectl set-hostname 

配置时间同步：
# yum -y install chrony

在master主机上执行：

将桥接的IPv4流量传递到iptables的链：
[root@master ~]# cat > /etc/sysctl.d/k8s.conf << EOF
> net.bridge.bridge-nf-call-ip6tables = 1
> net.bridge.bridge-nf-call-iptables = 1
> EOF
[root@master ~]# sysctl --system	# 生效

在master添加hosts：
[root@master ~]# cat >> /etc/hosts << EOF
> 192.168.10.201 master master.example.com
> 192.168.10.202 node1 node1.example.com
> 192.168.10.203 node2 node2.example.com
> EOF

免密认证：
[root@master ~]# ssh-keygen -t rsa
[root@master ~]# ssh-copy-id master
[root@master ~]# ssh-copy-id node1
[root@master ~]# ssh-copy-id node2

然后重启所有主机

3.安装Docker/kubeadm/kubelet

Kubernetes默认CRI（容器运行时）为Docker，因此先安装Docker。

所有主机安装docker

# wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
# yum -y install docker-ce
# systemctl enable --now docker
# docker --version

# cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://lngv2rof.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

所有主机添加kubernetes阿里云YUM软件源

地址：kubernetes镜像-kubernetes下载地址-kubernetes安装教程-阿里巴巴开源镜像站 (aliyun.com)

# cat > /etc/yum.repos.d/kubernetes.repo << EOF
[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

所有主机安装kubeadm，kubelet和kubectl

由于版本更新频繁，这里指定版本号部署：

# yum install -y kubelet-1.20.0 kubeadm-1.20.0 kubectl-1.20.0

！！安装完成以后不要启动，设置开机自启动即可
# systemctl enable kubelet

4.部署Kubernetes Master

在master主机上执行

[root@master ~]# kubeadm init \
  --apiserver-advertise-address=192.168.122.131 \		##此处是kubernetes master主机IP
  --image-repository registry.aliyuncs.com/google_containers \	##指定阿里云镜像仓库地址。
  --kubernetes-version v1.20.0 \		##刚刚安装的kubernetes的版本
  --service-cidr=10.96.0.0/12 \
  --pod-network-cidr=10.244.0.0/16

[init] Using Kubernetes version: v1.20.0
[preflight] Running pre-flight checks
        [WARNING FileExisting-tc]: tc not found in system path
        [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.12. Latest validated version: 19.03
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local master.example.com] and IPs [10.96.0.1 192.168.10.201]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [localhost master.example.com] and IPs [192.168.10.201 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [localhost master.example.com] and IPs [192.168.10.201 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 12.502159 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.20" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node master.example.com as control-plane by adding the labels "node-role.kubernetes.io/master=''" and "node-role.kubernetes.io/control-plane='' (deprecated)"
[mark-control-plane] Marking the node master.example.com as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 0lsupo.vxs0s7w6l78okdod
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

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 192.168.10.201:6443 --token 0lsupo.vxs0s7w6l78okdod \
    --discovery-token-ca-cert-hash sha256:eac059c0df6a4e49e749580cf88b4412c52a68c264aa77cca36ef4dc86eb8dfa
##保存好此处的命令
[root@master ~]# vim init
kubeadm join 192.168.10.201:6443 --token 0lsupo.vxs0s7w6l78okdod \
    --discovery-token-ca-cert-hash sha256:eac059c0df6a4e49e749580cf88b4412c52a68c264aa77cca36ef4dc86eb8dfa

设置环境变量使用kubectl工具

[root@master ~]# echo 'export KUBECONFIG=/etc/kubernetes/admin.conf' > /etc/profile.d/k8s.sh
[root@master ~]# source /etc/profile.d/k8s.sh

非root用户使用kubectl工具还需要做下面的事

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

查看当前镜像和容器

[root@master ~]# docker images 
REPOSITORY                                                        TAG        IMAGE ID       CREATED         SIZE
registry.aliyuncs.com/google_containers/kube-proxy                v1.20.0    10cc881966cf   12 months ago   118MB
registry.aliyuncs.com/google_containers/kube-apiserver            v1.20.0    ca9843d3b545   12 months ago   122MB
registry.aliyuncs.com/google_containers/kube-controller-manager   v1.20.0    b9fa1895dcaa   12 months ago   116MB
registry.aliyuncs.com/google_containers/kube-scheduler            v1.20.0    3138b6e3d471   12 months ago   46.4MB
registry.aliyuncs.com/google_containers/etcd                      3.4.13-0   0369cf4303ff   15 months ago   253MB
registry.aliyuncs.com/google_containers/coredns                   1.7.0      bfe3a36ebd25   18 months ago   45.2MB
registry.aliyuncs.com/google_containers/pause                     3.2        80d28bedfe5d   22 months ago   683kB
[root@master ~]#

[root@master ~]# docker ps
CONTAINER ID   IMAGE                                               COMMAND                  CREATED          STATUS          PORTS     NAMES
3211d07aea83   10cc881966cf                                        "/usr/local/bin/kube…"   15 minutes ago   Up 15 minutes             k8s_kube-proxy_kube-proxy-59qr6_kube-system_c3cfcd07-6dd3-47ca-882b-246860ac6452_0
42a2b6d506df   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 15 minutes ago   Up 15 minutes             k8s_POD_kube-proxy-59qr6_kube-system_c3cfcd07-6dd3-47ca-882b-246860ac6452_0
188cd1666a9d   3138b6e3d471                                        "kube-scheduler --au…"   15 minutes ago   Up 15 minutes             k8s_kube-scheduler_kube-scheduler-master.example.com_kube-system_0378cf280f805e38b5448a1eceeedfc4_0
0ea1a7607bbd   ca9843d3b545                                        "kube-apiserver --ad…"   15 minutes ago   Up 15 minutes             k8s_kube-apiserver_kube-apiserver-master.example.com_kube-system_26147bc137c63c92fa90fcbaf5bffa1b_0
9b99bda3213c   0369cf4303ff                                        "etcd --advertise-cl…"   15 minutes ago   Up 15 minutes             k8s_etcd_etcd-master.example.com_kube-system_55560107e174c866995e72ad649df97e_0
cd369525a53f   b9fa1895dcaa                                        "kube-controller-man…"   15 minutes ago   Up 15 minutes             k8s_kube-controller-manager_kube-controller-manager-master.example.com_kube-system_5c575d17517839b576ab4817fd06353f_0
880f36df090a   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 15 minutes ago   Up 15 minutes             k8s_POD_kube-scheduler-master.example.com_kube-system_0378cf280f805e38b5448a1eceeedfc4_0
b5b782317b59   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 15 minutes ago   Up 15 minutes             k8s_POD_kube-controller-manager-master.example.com_kube-system_5c575d17517839b576ab4817fd06353f_0
51164916d695   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 15 minutes ago   Up 15 minutes             k8s_POD_kube-apiserver-master.example.com_kube-system_26147bc137c63c92fa90fcbaf5bffa1b_0
aa0215a17700   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 15 minutes ago   Up 15 minutes             k8s_POD_etcd-master.example.com_kube-system_55560107e174c866995e72ad649df97e_0
[root@master ~]# 

查看集群节点

[root@master ~]# kubectl get nodes
NAME                 STATUS     ROLES                  AGE   VERSION
master.example.com   NotReady   control-plane,master   16m   v1.20.0	
# "NotReady"表示还没就绪，后台还有任务在进行
[root@master ~]#

5.master主机安装Pod网络插件（CNI）

[root@master ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

如果无法连接，可以将这个链接点开复制里面的内容到一个文件内，然后指定文件

[root@master ~]# vi flannel.yaml
---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: psp.flannel.unprivileged
  annotations:
    seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
    seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
    apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
    apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
  privileged: false
。。。。。。。略
[root@master ~]# kubectl apply -f flannel.yaml 
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created
[root@master ~]#

6.加入Kubernetes Node

在node节点上执行刚刚保存的命令

[root@node1 ~]# kubeadm join 192.168.10.201:6443 --token 0lsupo.vxs0s7w6l78okdod \
>     --discovery-token-ca-cert-hash sha256:eac059c0df6a4e49e749580cf88b4412c52a68c264aa77cca36ef4dc86eb8dfa
[preflight] Running pre-flight checks
        [WARNING FileExisting-tc]: tc not found in system path
        [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.12. Latest validated version: 19.03
        [WARNING Hostname]: hostname "node1.example.com" could not be reached
        [WARNING Hostname]: hostname "node1.example.com": lookup node1.example.com on 114.114.114.114:53: no such host
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

#和node1一样
[root@node2 ~]# kubeadm join 192.168.10.201:6443 --token 0lsupo.vxs0s7w6l78okdod \
>     --discovery-token-ca-cert-hash sha256:eac059c0df6a4e49e749580cf88b4412c52a68c264aa77cca36ef4dc86eb8dfa

在master主机查看

[root@master ~]# kubectl get nodes
NAME                 STATUS     ROLES                  AGE   VERSION
master.example.com   Ready      control-plane,master   46m   v1.20.0
node1.example.com    Ready                       28m   v1.20.0
node2.example.com    Ready   	                 22m   v1.20.0

7.测试kubernetes集群

# 创建一个pod，是deployment类型的nginx，使用nginx镜像，没有指定在哪个节点运行
[root@master ~]# kubectl create deployment nginx --image=nginx
deployment.apps/nginx created

# 暴露pod是deployment类型的nginx端口80，暴露在节点上
[root@master ~]# kubectl expose deployment nginx --port=80 --type=NodePort
service/nginx exposed

# 查看
[root@master ~]# kubectl get svc,pod
NAME                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
service/kubernetes   ClusterIP   10.96.0.1                443/TCP        51m
service/nginx        NodePort    10.103.221.120           80:30724/TCP   15s

NAME                         READY   STATUS              RESTARTS   AGE
pod/nginx-6799fc88d8-kdx4m   0/1     ContainerCreating   0          35s

# 查看在哪个节点上运行
[root@master ~]# kubectl get pod -o wide
NAME                     READY   STATUS    RESTARTS   AGE   IP           NODE                NOMINATED NODE   READINESS GATES
nginx-6799fc88d8-kdx4m   1/1     Running   0          73s   10.244.2.2   node2.example.com              

#查看master端端口
[root@master ~]# ss -antl
State      Recv-Q     Send-Q          Local Address:Port            Peer Address:Port     Process     
LISTEN     0          128            192.168.10.201:2380                 0.0.0.0:*
LISTEN     0          128                 127.0.0.1:33357                0.0.0.0:*
LISTEN     0          128                 127.0.0.1:2381                 0.0.0.0:*
LISTEN     0          128                 127.0.0.1:10257                0.0.0.0:*
LISTEN     0          128                 127.0.0.1:10259                0.0.0.0:*
LISTEN     0          128                   0.0.0.0:22                   0.0.0.0:*
LISTEN     0          128                   0.0.0.0:30724                0.0.0.0:*
LISTEN     0          128                 127.0.0.1:10248                0.0.0.0:*
LISTEN     0          128                 127.0.0.1:10249                0.0.0.0:*
LISTEN     0          128            192.168.10.201:2379                 0.0.0.0:*
LISTEN     0          128                 127.0.0.1:2379                 0.0.0.0:*
LISTEN     0          128                         *:10256                      *:*
LISTEN     0          128                      [::]:22                      [::]:*
LISTEN     0          128                         *:10250                      *:*
LISTEN     0          128                         *:6443                       *:*
[root@master ~]#

访问网站查看页面 master端IP:暴露端口