K8s權威指南學習

• 第一章 k8s入門（簡單的Java web項目）

  環境： VMware Workstation在本機虛擬一個64位的Centos7虛擬機

  • 環境準備

    1. 關閉防火牆

       systemctl disable firewalld
       systemctl stop firewalld

    2. 安裝etcd和Kubernetes軟件（會自動安裝Docker軟件）

       yum install -y etcd kubernetes

    3. 按順序啓動全部服務

       systemctl start etcd
       systemctl start docker
       systemctl start kube-apiserver
       systemctl start kube-controller-manager
       systemctl start kube-scheduler
       systemctl start kubelet
       systemctl start kube-proxy

  • 啓動MySQL服務

    1. MySQL鏡像

       docker pull daocloud.io/library/mysql:latest

    2. 構建Mysql RC定義文件(可使用vim建立)，命名mysql-rc.yaml 內容以下：

       apiVersion: v1
       kind: ReplicationController
       metadata:
         name: mysql
       	spec:
       	  replicas: 1
       	  selector:
       		app: mysql
       	  template:
       		metadata:
       		  labels:
       			app: mysql
       		spec:
       		  containers:
       		  - name: mysql
       			image: mysql
       			ports:
       			- containerPort: 3306
       			env:
       			- name: MYSQL_ROOT_PASSWORD
       			  value: "123456"

    3. 發佈到kubernetes集羣中，在master節點執行命令（注：此時可能出現問題，如：問題1：no resource found，問題2：status的狀態是ContainerCreating而不是running，若是出現此問題請看關於建立rc和pod出現的問問題）

       $ kubectl create -f mysql-rc.yaml 
       replicationcontroller "mysql" created

       查看建立的rc

       $ kubectl get rc 
       NAME DESIRED CURRENT READY AGE 
       mysql 1 1 1 14s

       查看pod建立狀況

       $ kubectl get pods 
       NAME READY STATUS RESTARTS AGE 
       mysql-srd1m 1/1 Running 0 41s

    4. 建立一個與之關聯的k8s Service-Mysql的定義文件（文件名爲mysql-svc.yaml）,內容以下：

       apiVersion: v1
       kind: Service
       metadata:
       name: mysql
       spec:
       ports:
       - port: 3306
       selector:
       app: mysql

       運行kubectl命令，建立service

       kubectl create -f mysql-svc.yaml

       查看剛剛建立的service

       $ kubectl get svc
       NAME         CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
       kubernetes   10.254.0.1     <none>        443/TCP    8d
       mysql        10.254.55.41   <none>        3306/TCP   13s

  • 啓動Tomcat服務

    1. 拉取Tomcat鏡像

       docker pull kubeguide/tomcat-app:v2

    2. 構建Tomcat RC定義文件，命名myweb-rc.yaml 內容以下：

       apiVersion: v1
       		kind: ReplicationController
       		metadata:
       		  name: myweb
       		spec:
       		  replicas: 2
       		  selector:
       			app: myweb
       		  template:
       			metadata:
       			  labels:
       				app: myweb
       			spec:
       			  containers:
       				- name: myweb
       				  image: kubeguide/tomcat-app:v1
       				  ports:
       				  - containerPort: 8080

       完成rc建立和驗證

       $ kubectl create -f myweb-rc.yaml 
       	replicationcontroller "myweb" created
       	$ kubectl get rc 
       	NAME      DESIRED   CURRENT   READY     AGE
       	mysql     1         1         1         23h
       	myweb     2         2         2         12s
       	$ kubectl get pods
       	NAME          READY     STATUS    RESTARTS   AGE
       	mysql-srd1m   1/1       Running   1          23h
       	myweb-fqlvz   1/1       Running   0          40s
       	myweb-ggrlg   1/1       Running   0          40s

    3. 建立對應的Service，文件名（myweb-svc.yaml）,內容以下

       apiVersion: v1
       	kind: Service
       	metadata: 
       	name: myweb
       	spec:
       	type: NodePort
       	ports:
       	- port: 8080
       	nodePort: 30001
       	selector:
       	app: myweb

       建立並驗證

       $ kubectl create -f myweb-svc.yaml 
       	service "myweb" created
       	$ kubectl get services
       	NAME         CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
       	kubernetes   10.254.0.1       <none>        443/TCP          8d
       	mysql        10.254.55.41     <none>        3306/TCP         42m
       	myweb        10.254.237.187   <nodes>       8080:30001/TCP   21s