K8s权威指南学习

• 第一章 k8s入门（简单的Java web项目）

  环境： VMware Workstation在本机虚拟一个64位的Centos7虚拟机

  • 环境准备

    1. 关闭防火墙

       systemctl disable firewalld
       systemctl stop firewalld
       

    2. 安装etcd和Kubernetes软件（会自动安装Docker软件）

       yum install -y etcd kubernetes
       

    3. 按顺序启动所有服务

       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
       

  • 启动MySQL服务

    1. MySQL镜像

       docker pull daocloud.io/library/mysql:latest
       

    2. 构建Mysql RC定义文件(可以使用vim创建)，命名mysql-rc.yaml 内容如下：

       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. 发布到kubernetes集群中，在master节点执行命令（注：此时可能出现问题，如：问题1：no resource found，问题2：status的状态是ContainerCreating而不是running，如果出现此问题请看关于创建rc和pod出现的问问题）

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

       查看创建的rc

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

       查看pod创建情况

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

    4. 创建一个与之关联的k8s Service-Mysql的定义文件（文件名为mysql-svc.yaml）,内容如下：

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

       运行kubectl命令，创建service

       kubectl create -f mysql-svc.yaml
       

       查看刚刚创建的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
       

  • 启动Tomcat服务

    1. 拉取Tomcat镜像

       	docker pull kubeguide/tomcat-app:v2
       

    2. 构建Tomcat RC定义文件，命名myweb-rc.yaml 内容如下：

       		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创建和验证

       	$ 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. 创建对应的Service，文件名（myweb-svc.yaml）,内容如下

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

       创建并验证

       	$ 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