kubernetes学习笔记（三）——利用kubeadm部署集群

文章目录

（一）安装前准备
（二）master安装

1、安装组件
2、排错

（三）node安装

1、安装组件
2、加入master
3、排错

（四）网络安装
（五）dashboard安装

（一）安装前准备

由于我是在笔记本虚拟机中安装，笔记本性能有限，所以这里就只安装一个node和一个master。准备工作如下，部署好两个虚拟机，都安装好centos7.4系统和docker。

–	ip	docker	系统
master	192.168.226.140	1.13.1	centos7.4
node	192.168.226.141	1.13.1	centos7.4

以下两步所有节点都需要操作。

1、修改docker镜像源为国内源

sudo vim /etc/docker/daemon.json

{

	"registry-mirrors": ["https://registry.docker-cn.com"]

}

systemctl enable docker.service

重启docker服务: systemctl restart docker

2、配置kubenetes阿里镜像源

vim /etc/yum.repos.d/kubernetes.repo

[kubernetes]

name=Kubernetes

baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64 enabled=1

gpgcheck=0

（二）master安装

1、安装组件

Master节点需要安装以下组件

组件	作用
etcd	etcd负责保存Kubernetes Cluster的配置信息和各种资源的状态信息。当数据发生变化时， etcd会快速地通知Kubernetes相关组件
kube-apiserver	提供HTTP/HTTPS RESTful API，即Kubernetes API。 API Server是Kubernetes Cluster的前端接口
kube-controller-manager	Controller Manager负责管理Cluster各种资源，保证资源处于预期的状态。
kube-scheduler	Scheduler负责决定将Pod放在哪个Node上运行。 Scheduler在调度时会充分虑Cluster的拓扑结构，当前各个节点的负载，以及应用对高可用、性能、数据亲和性的需求。

以上组件都会以容器的方式由kubelet拉起。

sudo yum install socat kubelet kubeadm kubectl kubernetes-cni -y

sudo systemctl enable kubelet.service && sudo systemctl start kubelet.service

初始化master节点

kubeadm init --kubernetes-version=1.11.0 --apiserver-advertise-address 192.168.226.140 --pod-network-cidr=10.244.0.0/16

–apiserver-advertise-address指明用Master的哪个interface与Cluster 的其他节点通信。如果Master有多个interface，建议明确指定，如果不指定， kubeadm会自动选择有默认网关的interface。

在初始化master节点的时候需要去拉取镜像，但是会拉取失败，因为gcr.io被墙，可以下载大神们制作好的镜像。把拉取失败的镜像名填入下面的脚本中进行镜像拉取。

images=(coredns:1.1.3 pause:3.1 kube-controller-manager-amd64:v1.11.0 kube-scheduler-amd64:v1.11.0 kube-scheduler-amd64:v1.11.0 kube-proxy-amd64:v1.11.0 kube-apiserver-amd64:v1.11.0   etcd-amd64:3.2.18 kube-proxy-amd64:v1.11.0)

for imageName in ${images[@]} ; do

  docker pull cloudnil/$imageName

  docker tag cloudnil/$imageName k8s.gcr.io/$imageName

  docker rmi cloudnil/$imageName

done

拉取镜像后，执行kubeadm reset清除之前安装的残留，然后再次重试。

如果成功的话会有下面这个输出

[bootstraptoken] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token

[bootstraptoken] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster

[bootstraptoken] creating the "cluster-info" ConfigMap in the "kube-public" namespace

[addons] Applied essential addon: CoreDNS

[addons] Applied essential addon: kube-proxy

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/

You can now join any number of machines by running the following on each node

as root:

  kubeadm join 192.168.226.140:6443 --token ct127x.9vc3wev5zc48bzko --discovery-token-ca-cert-hash sha256:89aa40ed38fd00cbff53eccc2d859c6f91dbcbf064e108e52dc7089e9a472a6d

2、排错

1、进/var/log/messages查看具体错误信息

2、进入docker容器查看日志文件

[root@k8s-master ~]# kubeadm init --kubernetes-version=1.11.0 --apiserver-advertise-address 192.168.226.140 --pod-network-cidr=10.244.0.0/16

[init] using Kubernetes version: v1.11.0

[preflight] running pre-flight checks

I0923 19:45:32.731532   33481 kernel_validator.go:81] Validating kernel version

I0923 19:45:32.731693   33481 kernel_validator.go:96] Validating kernel config

	[WARNING Hostname]: hostname "k8s-master" could not be reached

	[WARNING Hostname]: hostname "k8s-master" lookup k8s-master on 8.8.8.8:53: no such host

[preflight] Some fatal errors occurred:

	[ERROR Swap]: running with swap on is not supported. Please disable swap

[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`

结果报上面的错误，hostname修改/etc/hosts文件配置好。swap错误可以用swapoff -a关闭。

上面错误解决后仍然起不来，docker ps -a 产看哪个服务没有起来。进去查看日志：etcdmain: open /etc/kubernetes/pki/etcd/peer.crt: permission denied

[root@k8s-master log]# docker ps -a

CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS                     PORTS               NAMES

4b7f4e07a116        a68bfbd73ab7           "kube-apiserver --..."   3 minutes ago       Exited (1) 3 minutes ago                       k8s_kube-apiserver_kube-apiserver-k8s-master_kube-system_561e3b45e6e68179a91caccad9c1a852_7

e100a2a11c24        78b282dd9c2e           "etcd --advertise-..."   3 minutes ago       Exited (1) 3 minutes ago                       k8s_etcd_etcd-k8s-master_kube-system_1129548e8dabf0990c651f2471eeb7e2_7

30b6059b4e90        c1211e0f980b           "kube-controller-m..."   14 minutes ago      Up 14 minutes                                  k8s_kube-controller-manager_kube-controller-manager-k8s-master_kube-system_d732e49a6ef43c8d652c917767ad4bc8_0

......

[root@k8s-master log]# docker logs e100a2a11c24

2018-09-23 13:30:38.435551 I | etcdmain: etcd Version: 3.2.18

2018-09-23 13:30:38.435879 I | etcdmain: Git SHA: eddf599c6

2018-09-23 13:30:38.435887 I | etcdmain: Go Version: go1.8.7

2018-09-23 13:30:38.435892 I | etcdmain: Go OS/Arch: linux/amd64

2018-09-23 13:30:38.435902 I | etcdmain: setting maximum number of CPUs to 2, total number of available CPUs is 2

2018-09-23 13:30:38.436132 I | embed: peerTLS: cert = /etc/kubernetes/pki/etcd/peer.crt, key = /etc/kubernetes/pki/etcd/peer.key, ca = , trusted-ca = /etc/kubernetes/pki/etcd/ca.crt, client-cert-auth = true

2018-09-23 13:30:38.436659 C | etcdmain: open /etc/kubernetes/pki/etcd/peer.crt: permission denied

上面这个错误我关闭了selinux就可以了。

[root@localhost ~]# setenforce 0 //临时关闭

[root@localhost ~]# getenforce

Permissive

[root@localhost ~]# vim /etc/sysconfig/selinux //永久关闭

将SELINUX=enforcing 改为 SELINUX=disabled 。

（三）node安装

1、安装组件

sudo yum install kubelet kubeadm kubectl -y

sudo systemctl enable kubelet.service && sudo systemctl start kubelet.service

2、加入master

[root@k8s-node ~]# kubeadm join 192.168.226.140:6443 --token ct127x.9vc3wev5zc48bzko --discovery-token-ca-cert-hash sha256:89aa40ed38fd00cbff53eccc2d859c6f91dbcbf064e108e52dc7089e9a472a6d

3、排错

出现这个错误：[ERROR Swap]: running with swap on is not supported. Please disable swap

执行swapoff -a关闭

（四）网络安装

这里安装flannel网络，需要在master和node节点都下载好两个镜像。

[root@k8s-master ~]#  curl -ssL https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml -o kube-flannel.yml

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

此处下载那个flannel镜像真心超级慢，我等了好久才下载成功。要有耐心。

（五）dashboard安装

安装控制台，先下载一个yaml文件。

[root@k8s-master ~]# curl -ssL https://raw.githubusercontent.com/winse/docker-hadoop/master/kube-deploy/kubeadm/kubernetes-dashboard.yaml -o kubernetes-dashboard.yml

[root@k8s-master ~]# kubectl apply -f kubernetes-dashboard.yml

采坑记录请参考：https://www.cnblogs.com/RainingNight/p/deploying-k8s-dashboard-ui.html

文中详细讲述了四种登入dashboard的方式：

经过尝试之后使用之后使用了最简单的第二种方式来访问：

使用kubectl -n kube-system edit service kubernetes-dashboard来编辑配置，将文件中的type: ClusterIP修改为type: NodePort，保存后使用kubectl get service命令来查看自动生产的端口

[root@k8s-master ~]# kubectl -n kube-system edit service kubernetes-dashboard

service/kubernetes-dashboard edited

[root@k8s-master ~]# kubectl get service

NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE

kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   2h

[root@k8s-master ~]# kubectl -n kube-system get service kubernetes-dashboard

NAME                   TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE

kubernetes-dashboard   NodePort   10.100.84.158   <none>        80:31248/TCP   52m

可以看到port为31248。然后查看dashboard具体运行在那个node或者master上面



[root@k8s-master ~]# kubectl get pods -n kube-system -o wide

NAME                                   READY     STATUS    RESTARTS   AGE       IP                NODE

.......

kube-proxy-8frqn                       1/1       Running   0          3h        192.168.226.140   k8s-master

kube-proxy-hv6lg                       1/1       Running   0          2h        192.168.226.141   k8s-node

kube-scheduler-k8s-master              1/1       Running   0          1h        192.168.226.140   k8s-master

kubernetes-dashboard-98bf745c6-xcxnm   1/1       Running   0          59m       10.244.1.5        k8s-node

我这里可以看到运行在k8s-node节点上面，也就是192.168.226.141上面，这样我就可以在windows浏览器里面打开：http://192.168.226.141:31248/#!/overview?namespace=default 就可以打开dashboard了。

至此k8s实验环境docker版安装算完成了。以后有空试一试二进制来安装，这也是最复杂的安装方式。