k8s安装

kubeadm

kubeadm是一个专门快速部署kubernetes集群的工具。
可以使用kubeadm init 来初始化master节点，然后使用kubeadm join 将其他的node节点加入到集群中
kubeadm通过一个简单的配置是将一个最小可用的集群运行起来

• 新用户可以从kubeadm开始快速搭建kubernetes
• 熟悉的人可以使用kubeadm快熟搭建集群并测试他们的应用
• 大型的项目可以配合其他工具，

官方文档
https://kubernetes.io/docs/reference/setup-tools/kubueadm/kubeadm
https://kubernetes.io/docs/setup/independet/install-kubeadm

基于kubeadm部署k8s

14 master kubeadm，kubelet，kubectl，docker
10 node01 kubeadm，kubelet，kubectl，docker
11 node02 kubeadm，kubelet，kubectl，docker

关闭防火墙个selinux

[root@master ~]# setenforce 0
setenforce: SELinux is disabled
[root@master ~]# iptables -F
[root@master ~]# systemctl stop firewalld
[root@master ~]# systemctl disable firewalld
[root@master ~]# systemctl stop NetworkManager
[root@master ~]# systemctl disable NetworkManger
Failed to execute operation: No such file or directory
[root@master ~]# systemctl disable NetworkManager
[root@master ~]# sed -i '/^SELINUX=/s/enforcing/disabled/' /etc/selinux/config 

部署主机并绑定hosts

[root@k8s-master ~]# vim /etc/hosts
192.168.200.14  k8s-master
192.168.200.10  k8s-node01
a92.168.200.11  k8s-node02
[root@master ~]# scp /etc/hosts 192.168.200.10:/etc/
[root@master ~]# scp /etc/hosts 192.168.200.20:/etc/

主机配置初识化

[root@k8s-master ~]# yum -y install vim wget net-tools lrzsz
[root@k8s-master ~]# swapoff -a
[root@k8s-master ~]# sed -i '/swap/s/^/#/' /etc/fstab
cat <<EOF>> /etc/sysctl.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
[root@k8s-master ~]# modprobe br_netfilter
[root@k8s-master ~]# sysctl -p
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1

所有主机部署docker环境

所有主机配置阿里云镜像加速

部署kubernetes集群

组件介绍

• kubeadm：安装工具，使所有的组件都会以容器的方式运行
• kubectl：客户端连接k8s api 工具
• kubelet：运行在node节点，用来启动容器的工具

推荐使用阿里云的yum源

所有主机安装kubelet kubeadm kubectl

yum install -y install kubelet-1.17.0 kubeadm-1.17.0 kubectl-1.17.0
[root@k8s-master k8s]# ls
conntrack-tools-1.4.4-7.el7.x86_64.rpm  kubernetes-cni-0.8.7-0.x86_64.rpm
cri-tools-1.13.0-0.x86_64.rpm           libnetfilter_cthelper-1.0.0-11.el7.x86_64.rpm
kubeadm-1.20.0-0.x86_64.rpm             libnetfilter_cttimeout-1.0.0-7.el7.x86_64.rpm
kubectl-1.20.0-0.x86_64.rpm             libnetfilter_queue-1.0.2-2.el7_2.x86_64.rpm
kubelet-1.20.0-0.x86_64.rpm
yum -y install *.rpm
[root@k8s-master ~]# systemctl enable kubelet.service 
#kubelet刚安装后是无法启动的，需要加入节点或者初始化为master后才可以启动

配置init-config.yaml
kubeadm的配置项都吨出在configMap中，可以将其写入配置文件，方便管理

#在master主机上配置
[root@k8s-master ~]# kubeadm config print init-defaults > init-config.yaml
#打印初始化相关的配置到config.yaml文件中

kubeadm config view：查看当前集群中的配置值
kubeadm config print join-defaults：输出kubeadm join 默认参数文件内容

init-config.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: 192.168.200.14  #master的ip
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: k8s-master
  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  #容器挂载到本地的目录
imageRepository: registry.aliyuncs.com/google_containers  #切换国内的镜像地址
kind: ClusterConfiguration
kubernetesVersion: v1.20.0
networking:
  dnsDomain: cluster.local
  serviceSubnet: 10.96.0.0/12
  podSubnet: 10.244.0.0/16  #新增pod网段
scheduler: {}

安装master节点

[root@k8s-master ~]# kubeadm config images list（pull） --config init-config.yaml  #查看配置文件关联的镜像（下载）
[root@k8s-master master]# ls
coredns_1.7.0.tar           kube-controller-manager_v1.20.0.tar  pause_3.2.tar
etcd_3.4.13-0.tar           kube-proxy_v1.20.0.tar
kube-apiserver_v1.20.0.tar  kube-scheduler_v1.20.0.tar
[root@k8s-master master]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
[root@k8s-master master]# ls | while read line
> do
> docker load < $line
> done  #保存镜像
[root@k8s-master ~]# docker images
REPOSITORY                                                        TAG                 IMAGE IDED             SIZE
registry.aliyuncs.com/google_containers/kube-proxy                v1.20.0             10cc8819nths ago       118MB
registry.aliyuncs.com/google_containers/kube-apiserver            v1.20.0             ca9843d3nths ago       122MB
registry.aliyuncs.com/google_containers/kube-controller-manager   v1.20.0             b9fa1895nths ago       116MB
registry.aliyuncs.com/google_containers/kube-scheduler            v1.20.0             3138b6e3nths ago       46.4MB
registry.aliyuncs.com/google_containers/etcd                      3.4.13-0            0369cf43nths ago       253MB
registry.aliyuncs.com/google_containers/coredns                   1.7.0               bfe3a36enths ago       45.2MB
registry.aliyuncs.com/google_containers/pause                     3.2                 80d28bednths ago       683kB
[root@k8s-master ~]# kubeadm init - -config=init-config.yaml  #初始化安装k8s

kubectl默认会在执行的用户家目录下面的。kube目录下寻找config文件，所以在当前目录下创建一个.kube文件，并且将初始化生成的admin.conf拷贝到./kube/config

初始化的时候会提示，直接拉取执行

初始化时

安装node节点

#初始化时自动提示，在node节点直接执行
[root@k8s-node01 ~]# kubeadm join 192.168.200.14:6443 --token abcdef.0123456789abcdef 
>     --discovery-token-ca-cert-hash sha256:546631d9bc3d6fe0043d6b4da27ec3332a2909b991cb66a4156760fc63be78ca 


--token（临时二十四小时连接验证）

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.
提示在master上执行kubectl get nodes，获取node节点信息

[root@k8s-master ~]# kubectl get nodes  
NAME         STATUS     ROLES                  AGE     VERSION
k8s-master   NotReady   control-plane,master   9m      v1.20.0
k8s-node01   NotReady   <none>                 2m17s   v1.20.0
k8s-node02   NotReady   <none>                 2m13s   v1.20.0

安装flannel
master节点notready 的原因就是没有网络插件。

此时master主机上传kube-flannel.yml 所有主机上传flannel_v0.12.0-amd64.tar

[root@k8s-master ~]# ls
docker  flannel_v0.12.0-amd64.tar  init-config.yaml  k8s  kube-flannel.yml  master
[root@k8s-master ~]# scp flannel_v0.12.0-amd64.tar 192.168.200.10:/root/
[root@k8s-master ~]# scp flannel_v0.12.0-amd64.tar 192.168.200.11:/root/

docker load < flannel_v0.12.0-amd64.tar  #所有主机导入镜像

[root@k8s-master ~]# kubectl apply -f kube-flannel.yml   #master运行

[root@k8s-master ~]# kubectl get nodes  #再次查看节点
NAME         STATUS   ROLES                  AGE   VERSION
k8s-master   Ready    control-plane,master   17m   v1.20.0
k8s-node01   Ready    <none>                 11m   v1.20.0
k8s-node02   Ready    <none>                 11m   v1.20.0
[root@k8s-master ~]# kubectl get pods -n kube-system

安装D安上board UI

所有主机部署Dashboard
默认这个部署文件中，会独立创建一个kubernetes-dashboard的命令空间。
dashboard的镜像来自于docker hub官方

[root@k8s-master ~]# ls
dashboard_v2.0.0.tar       init-config.yaml  master
docker                     k8s               metrics-scraper_v1.0.4.tar
flannel_v0.12.0-amd64.tar  kube-flannel.yml  recommended.yaml

[root@k8s-master ~]# docker load < dashboard_v2.0.0.tar 
[root@k8s-master ~]# docker load < metrics-scraper_v1.0.4.tar

[root@k8s-master ~]# vim recommended.yaml 
 41   ports:
 42     - port: 443
 43       targetPort: 8443
 44       nodePort: 32443
164   name: cluster-admin  #管理权限

[root@k8s-master ~]# kubectl apply -f recommended.yaml   #部署文件
[root@k8s-master ~]# kubectl get pods -n kubernetes-dashboard  #查看
NAME                                         READY   STATUS    RESTARTS   AGE
dashboard-metrics-scraper-7b59f7d4df-css6p   1/1     Running   0          38s
kubernetes-dashboard-74d688b6bc-nvhdj        1/1     Running   0          38s
#此时就可以使用浏览器访问
使用koten进入
[root@k8s-master ~]# kubectl describe secret -n kubernetes-dashboard $(kubectl get secret -n kubernetes-dashboard-token | awk '{print $1}') | grep token | awk '{print $2}'  #获取到密码

命名空间可详细查看

安装metrics-server
在node节点下载镜像

[root@k8s-node01 ~]# ls
dashboard_v2.0.0.tar  flannel_v0.12.0-amd64.tar  metrics-scraper_v1.0.4.tar
docker                k8s                        metrics-server-amd64_v0.3.6.tar
[root@k8s-node01 ~]# docker load < metrics-server-amd64_v0.3.6.tar 
932da5156413: Loading layer  3.062MB/3.062MB
7bf3709d22bb: Loading layer  38.13MB/38.13MB
Loaded image: bluersw/metrics-server-amd64:v0.3.6
[root@k8s-node01 ~]# docker tag bluersw/metrics-server-amd64:v0.3.6 k8s.gcr.io/metrics-server-amd64:v0.3.6

修改kubernetes apiserver启动参数

[root@k8s-master ~]# vim /etc/kubernetes/manifests/kube-apiserver.yaml 
 44     - --enable-aggregator-routing=true  #添加的

下载一个配置文件
[root@k8s-master ~]# kubectl create -f components.yaml 

#此时就可以查看状态了
[root@k8s-master ~]# kubectl top nodes
NAME         CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
k8s-master   235m         5%     1187Mi          69%       
k8s-node01   81m          2%     749Mi           43%       
k8s-node02   68m          1%     825Mi           48%