Kubernetes学习总结：

第一部分是自己对Kubernetes的认识做一个记录和总结。
第二部分是在本地搭建起Kubernetes集群，并上手体验。

认识 Kubernetes

什么是 Kubernetes？

Kubernetes是在集群中跨多主机用于自动部署、扩展和管理容器化（containerized）应用程序的开源系统，kubernetes提供了诸多机制用来进行应用部署，调度，更新，维护和伸缩，以确保集群的状态是持续健康的。

Kubernete能帮我们达成以下目标：

跨多台主机进行容器编排。
更加充分地利用硬件，最大程度获取运行企业应用所需的资源。
有效管控应用部署和更新，并实现自动化操作。
挂载和增加存储，用于运行有状态的应用。
快速、按需扩展容器化应用及其资源。
对服务进行声明式管理，以保证所部署的应用始终按照您部署的方式加以运行。
利用自动布局、自动重启、自动复制以及自动扩展功能，对应用实施状况检查和自我修复。

Kubernetes 架构图

Kubernetes 核心概念和组件

体验 Kubernetes

想要在本地运行Kubernetes有如下方式

Minikube
kubeadm
自定义安装：创建虚拟机，安装kubernetes需要的服务组件

在这我们使用第二种方式

1. 部署的环境准备

我们使用Vagrant来虚拟化, bento/ubuntu-16.04 可以提前下载，由于安装过程需要访问被墙的资源，所以要配置http_proxy, 可以使用主机上的Shadowsocks代理。

主机环境：Mac OS
虚拟机环境： Vagrant (bento/ubuntu-16.04)
虚拟机provider：VirtualBox
代理：Shadowsocks （安装过程需要访问google资源）

2. 编写 Vagrantfile

2.1 配置1个master，2个node，`$script`是初始化虚拟机执行的命令（安装，配置软件等）

Vagrant.configure("2") do |config|
  config.vm.box = "bento/ubuntu-16.04"
  config.vm.network "public_network", bridge: "en0: Wi-Fi (AirPort)"

  config.vm.define "master" do |master|
    master.vm.network "private_network", ip: "192.168.10.10"
    master.vm.hostname = "master"
    master.vm.provision "shell", inline: $script
  end

  config.vm.define "node1" do |node1|
    node1.vm.network "private_network", ip: "192.168.10.11"
    node1.vm.hostname = "node1"
    node1.vm.provision "shell", inline: $script
  end

  config.vm.define "node2" do |node2|
    node2.vm.network "private_network", ip: "192.168.10.12"
    node2.vm.hostname = "node2"
    node2.vm.provision "shell", inline: $script
  end
end

2.2 虚拟机安装Docker

# Install docker
curl -sSL https://get.daocloud.io/docker | sh

# use Docker as a non-root user, add vagrat to docker group    
sudo usermod -a -G docker vagrant

# docker 配置代理
sudo mkdir /etc/systemd/system/docker.service.d
sudo touch /etc/systemd/system/docker.service.d/http-proxy.conf
sudo echo '
[Service]
Environment="HTTP_PROXY=http://192.168.10.1:1087" "HTTPS_PROXY=http://192.168.10.1:1087"
' > /etc/systemd/system/docker.service.d/http-proxy.conf

# restart docker
sudo systemctl daemon-reload
systemctl restart docker
sudo systemctl show docker --property Environment

2.3 虚拟机安装kubernetes

# Install kubernetes
sudo apt-get install -y apt-transport-https
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF

sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl

# kubelet requires swap off
sudo swapoff -a

# keep swap off after reboot
sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

3.初始化虚拟机

如果bento/ubuntu-16.04没有提前下载，会自动下载该box，然后分别配置master, node1,node2，如果安装过程出现问题，很有可能是http代理的问题

➜  k8s-vagrant-demo git:(master) ✗ vagrant up

初始化结束后，可以查看创建的虚拟机状态

➜  k8s-vagrant-demo git:(master) ✗ vagrant status
Current machine states:

master                    running (virtualbox)
node1                     running (virtualbox)
node2                     running (virtualbox)

This environment represents multiple VMs. The VMs are all listed
above with their current state. For more information about a specific
VM, run `vagrant status NAME`.

进入master节点验证虚拟机配置的状态

➜  k8s-vagrant-demo git:(master) ✗ vagrant ssh master
...
vagrant@master:~$ docker version
Client:
 Version:           18.06.1-ce
 API version:       1.38
 Go version:        go1.10.3
 Git commit:        e68fc7a
 Built:             Tue Aug 21 17:24:56 2018
 OS/Arch:           linux/amd64
 Experimental:      false

Server:
 Engine:
  Version:          18.06.1-ce
  API version:      1.38 (minimum version 1.12)
  Go version:       go1.10.3
  Git commit:       e68fc7a
  Built:            Tue Aug 21 17:23:21 2018
  OS/Arch:          linux/amd64
  Experimental:     false
vagrant@master:~$ kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"12", GitVersion:"v1.12.1", GitCommit:"4ed3216f3ec431b140b1d899130a69fc671678f4", GitTreeState:"clean", BuildDate:"2018-10-05T16:43:08Z", GoVersion:"go1.10.4", Compiler:"gc", Platform:"linux/amd64"}

4. 配置集群

初始化集群 使用kubeadm init 初始化集群

vagrant@master:~$ sudo kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.10.10  --node-name=master
... 此处略去很多log
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 192.168.10.10:6443 --token wu7vfc.1129cjxfenww631q --discovery-token-ca-cert-hash sha256:d48541246b9febd8c1f377996a18f196e7adab7c966406506b52de86a96e4df0

设置配置文件

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

添加Flannel，pod network

vagrant@master:~$ sudo kubectl apply -f  https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.extensions/kube-flannel-ds-amd64 created
daemonset.extensions/kube-flannel-ds-arm64 created
daemonset.extensions/kube-flannel-ds-arm created
daemonset.extensions/kube-flannel-ds-ppc64le created
daemonset.extensions/kube-flannel-ds-s390x created

vagrant@master:~$ sudo kubectl get pods --all-namespaces
NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE
kube-system   coredns-576cbf47c7-6x85t         1/1     Running   0          17h
kube-system   coredns-576cbf47c7-j9dzl         1/1     Running   0          17h
kube-system   etcd-master                      1/1     Running   0          3m29s
kube-system   kube-apiserver-master            1/1     Running   0          3m29s
kube-system   kube-controller-manager-master   1/1     Running   0          3m28s
kube-system   kube-flannel-ds-amd64-tf9jz      1/1     Running   0          4m4s
kube-system   kube-proxy-nb2sk                 1/1     Running   0          17h
kube-system   kube-scheduler-master            1/1     Running   0          3m28s

将node1, node2加入到集群中

vagrant ssh node1
vagrant@node1:~$ sudo kubeadm join 192.168.10.10:6443 --token wu7vfc.1129cjxfenww631q --discovery-token-ca-cert-hash sha256:d48541246b9febd8c1f377996a18f196e7adab7c966406506b52de86a96e4df0

vagrant ssh node2
vagrant@node2:~$ sudo kubeadm join 192.168.10.10:6443 --token wu7vfc.1129cjxfenww631q --discovery-token-ca-cert-hash sha256:d48541246b9febd8c1f377996a18f196e7adab7c966406506b52de86a96e4df0

在master节点上查看所有的nodes

vagrant@master:~$ kubectl get nodes
NAME     STATUS   ROLES    AGE     VERSION
master   Ready    master   17h     v1.12.1
node1    Ready    <none>   8m27s   v1.12.1
node2    Ready    <none>   8m24s   v1.12.1

到此我们的kubernetes集群就搭建完毕，下面我们来部署kubernetes-dashboard，然后就可以通过图形化界面来操作集群。

5. 安装kubernetes-dashboard

安装dashboard

vagrant@master:~$ sudo kubectl create -f https://gist.githubusercontent.com/aiooly/60cb0d150e0884e5f44e654fe3cb1168/raw/feea0964aa692b3b0974f3c7f4e3d5989db2e5a9/kubernetes-dashboard.yaml
serviceaccount/kubernetes-dashboard created
role.rbac.authorization.k8s.io/kubernetes-dashboard-minimal created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard-minimal created
deployment.apps/kubernetes-dashboard created
service/kubernetes-dashboard created

查看dashboard service

vagrant@master:~$ kubectl get svc -n kube-system
NAME                   TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)         AGE
kube-dns               ClusterIP   10.96.0.10    <none>        53/UDP,53/TCP   18h
kubernetes-dashboard   NodePort    10.96.4.159   <none>        80:30091/TCP    32s

创建clusterrolebinding

vagrant@master:~$ kubectl create clusterrolebinding add-on-cluster-admin --clusterrole=cluster-admin --serviceaccount=kube-system:kubernetes-dashboard
clusterrolebinding.rbac.authorization.k8s.io/add-on-cluster-admin created

浏览器打开dashboard UI

找到dashboard运行的节点

vagrant@master:~$ kubectl get services -n kube-system -o wide
NAME                   TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)         AGE   SELECTOR
kube-dns               ClusterIP   10.96.0.10    <none>        53/UDP,53/TCP   19h   k8s-app=kube-dns
kubernetes-dashboard   NodePort    10.96.4.159   <none>        80:30091/TCP    88m   k8s-app=kubernetes-dashboard
vagrant@master:~$ kubectl get pods --selector="k8s-app=kubernetes-dashboard" -n kube-system -o wide
NAME                                  READY   STATUS    RESTARTS   AGE   IP           NODE    NOMINATED NODE
kubernetes-dashboard-c5b44fc5-8n2gp   1/1     Running   6          88m   10.244.1.2   node1   <none>

在主机上打开浏览器，输入：http://192.168.10.11:30091, 如下图：

6. 部署 hello-world

创建hello-world部署

kubectl run hello-world --replicas=1 --labels="app=hello-world" --image=nginx:1.7.9  --port=80

**可以通过下面的命令查看部署情况 **

vagrant@master:~$ kubectl get deployments -o wide
NAME          DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE    CONTAINERS    IMAGES        SELECTOR
hello-world   1         1         1            1           111s   hello-world   nginx:1.7.9   app=hello-world
vagrant@master:~$ kubectl get pods -o wide
NAME                          READY   STATUS    RESTARTS   AGE    IP           NODE    NOMINATED NODE
hello-world-956d45bf6-5k9b5   1/1     Running   0          115s   10.244.2.2   node2   <none>

创建hello-world-service来暴露服务，使集群外可以访问 这里我们使用NodePort

kubectl expose deployment hello-world --type=NodePort --name=hello-world-service

查看刚部署的应用的状态

vagrant@master:~$ kubectl get services hello-world-service -o wide
NAME                  TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE     SELECTOR
hello-world-service   NodePort   10.104.119.39   <none>        80:30748/TCP   4m37s   app=hello-world
vagrant@master:~$ kubectl get pods -o wide
NAME                          READY   STATUS    RESTARTS   AGE   IP           NODE    NOMINATED NODE
hello-world-956d45bf6-5k9b5   1/1     Running   0          32m   10.244.2.2   node2   <none>

或者可以在dashboard上查看

浏览器访问: NodeIP:NodePort

Name		Name	Last commit message	Last commit date
Latest commit History 6 Commits
.gitignore		.gitignore
README.md		README.md
Vagrantfile		Vagrantfile

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Repository files navigation

Kubernetes学习总结：

目录

认识 Kubernetes

什么是 Kubernetes？

Kubernetes 架构图

Kubernetes 核心概念和组件

体验 Kubernetes

1. 部署的环境准备

2. 编写 Vagrantfile

2.1 配置1个master，2个node，`$script`是初始化虚拟机执行的命令（安装，配置软件等）

2.2 虚拟机安装Docker

2.3 虚拟机安装kubernetes

3.初始化虚拟机

4. 配置集群

5. 安装kubernetes-dashboard

6. 部署 hello-world

About

Releases

Packages

aiooly/k8s-learning-introduction

Folders and files

Latest commit

History

Repository files navigation

Kubernetes学习总结：

目录

认识 Kubernetes

什么是 Kubernetes？

Kubernetes 架构图

Kubernetes 核心概念和组件

体验 Kubernetes

1. 部署的环境准备

2. 编写 Vagrantfile

2.1 配置1个master，2个node，$script是初始化虚拟机执行的命令（安装，配置软件等）

2.2 虚拟机安装Docker

2.3 虚拟机安装kubernetes

3.初始化虚拟机

4. 配置集群

5. 安装kubernetes-dashboard

6. 部署 hello-world

About

Resources

Stars

Watchers

Forks

Releases

Packages 0

2.1 配置1个master，2个node，`$script`是初始化虚拟机执行的命令（安装，配置软件等）

Packages