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

本文转移开源中国-K8s权威指南学习