学习了K8S的基础知识,我们的目的就是解决我们服务的迁移,那么接下去通过几个案例来感受一下K8s部署带来的便捷与效率。

环境准备:

  3个节点,然后我这边也安装了 Ingress。

部署wordpress+mysql(Service:NodePort模式):

(1)创建wordpress命名空间

  kubectl create namespace wordpress

  kubectl get ns

(2)创建wordpress-db.yaml文件,根据wordpress-db.yaml创建资源[mysql数据库]

apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name: mysql-deploy
  namespace: wordpress
  labels:
    app: mysql
spec:
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - name: mysql
        image: mysql:5.6
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 3306
          name: dbport
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: rootPassW0rd
        - name: MYSQL_DATABASE
          value: wordpress
        - name: MYSQL_USER
          value: wordpress
        - name: MYSQL_PASSWORD
          value: wordpress
        volumeMounts:
        - name: db
          mountPath: /var/lib/mysql
      volumes:
      - name: db
        hostPath:
          path: /var/lib/mysql
---
apiVersion: v1
kind: Service
metadata:
  name: mysql
  namespace: wordpress
spec:
  selector:
    app: mysql
  ports:
  - name: mysqlport
    protocol: TCP
    port: 3306
    targetPort: dbport

  kubectl apply -f wordpress-db.yaml

  kubectl get pods -n wordpress

  kubectl get svc mysql -n wordpress

  kubectl describe svc mysql -n wordpress 记录下 Endpoints的IP   或者IP ,需要配置到wordpress里面。

 

(3)创建wordpress.yaml文件,根据wordpress.yaml创建资源[wordpress]

apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name: wordpress-deploy
  namespace: wordpress
  labels:
    app: wordpress
spec:
  template:
    metadata:
      labels:
        app: wordpress
    spec:
      containers:
      - name: wordpress
        image: wordpress
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
          name: wdport
        env:
        - name: WORDPRESS_DB_HOST
          value: 192.168.190.102:3306                     
        - name: WORDPRESS_DB_USER
          value: wordpress
        - name: WORDPRESS_DB_PASSWORD
          value: wordpress
---
apiVersion: v1
kind: Service
metadata:
  name: wordpress
  namespace: wordpress
spec:
  type: NodePort
  selector:
    app: wordpress
  ports:
  - name: wordpressport
    protocol: TCP
    port: 80
    targetPort: wdport

  kubectl apply -f wordpress.yaml #修改其中mysql的ip地址,其实也可以使用service的name:mysql

  kubectl get pods -n wordpress 

  kubectl get svc -n wordpress # 获取到转发后的端口,如这里的30078

(6)访问测试,win上访问集群中任意宿主机节点的IP:30078

 

部署Spring Boot项目(Ingress):

 流程:确定服务-->编写Dockerfile制作镜像-->上传镜像到仓库-->编写K8S文件-->创建

(1)准备Spring Boot项目springboot-demo

@RestController
@RequestMapping("wuzz")
public class TestController {
    @RequestMapping(value = "/k8s", method = {RequestMethod.GET})
    public String k8s() {
        return "Hello Kubernetes .....";
    }
}

(2) mvn clean install生成xxx.jar,并且上传到 linux 自定义目录下(我这边是 /mysoft)

(3)编写Dockerfile文件 cd /mysoft 下 vi Dockerfile

FROM openjdk:8-jre-alpine
COPY springboot-demo-1.0-SNAPSHOT.jar /mysoft/springboot-demo.jar
ENTRYPOINT ["java","-jar","/mysoft/springboot-demo.jar"]

(4)根据Dockerfile创建image

  docker build -t springboot-demo-image .

(5)使用docker run创建container

  docker run -d --name s1 springboot-demo-image

(6)访问测试

  docker inspect s1

  curl ip:8080/wuzz/k8s

(7)将镜像推送到镜像仓库

 # 登录阿里云镜像仓库

sudo docker login --username=随风去wuzz registry.cn-hangzhou.aliyuncs.com

docker tag springboot-demo-image registry.cn-hangzhou.aliyuncs.com/wuzz-docker/springboot-demo-image:v1.0

docker push registry.cn-hangzhou.aliyuncs.com/wuzz-docker/springboot-demo-image:v1.0

 

  推送完成。

 

(8)编写Kubernetes配置文件vi springboot-demo.yaml

# 以Deployment部署Pod
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: springboot-demo
spec: 
  selector: 
    matchLabels: 
      app: springboot-demo
  replicas: 1
  template: 
    metadata:
      labels: 
        app: springboot-demo
    spec: 
      containers: 
      - name: springboot-demo
        image: registry.cn-hangzhou.aliyuncs.com/wuzz-docker/springboot-demo-image:v1.0
        ports: 
        - containerPort: 8080
---
# 创建Pod的Service
apiVersion: v1
kind: Service
metadata: 
  name: springboot-demo
spec: 
  ports: 
  - port: 80
    protocol: TCP
    targetPort: 8080
  selector: 
    app: springboot-demo
---
# 创建Ingress,定义访问规则,一定要记得提前创建好nginx ingress controller
apiVersion: extensions/v1beta1
kind: Ingress
metadata: 
  name: springboot-demo
spec: 
  rules: 
  - host: tomcat.wuzz.com
    http: 
      paths: 
      - path: /
        backend: 
          serviceName: springboot-demo
          servicePort: 80

  生成 pod :kubectl apply -f springboot-demo.yaml

(9)查看资源

  kubectl get pods

  kubectl get pods -o wide

  curl 192.168.190.103:8080/wuzz/k8s

  kubectl get svc

  kubectl scale deploy springboot-demo --replicas=5

(10)win配置hosts文件[一定要记得提前创建好nginx ingress controller]  

  192.168.1.102  tomcat.wuzz.com

(11)win浏览器访问

部署传统分布式服务(user/order)及注册中心(Nacos):

  将user/order服务注册到nacos,user服务能够找到order服务。

(1).启动两个Spring Boot项目,两者Pom.xml如下:

<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.1.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.10</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <!-- SpringCloud 所有子项目 版本集中管理. 统一所有SpringCloud依赖项目的版本依赖-->
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>0.9.0.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.1.6.RELEASE</version>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.1.6.RELEASE</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

  application.properties :user端口8081,order9090,记得修改对应application.name

server.port=8081
spring.application.name=user
spring.cloud.nacos.discovery.server-addr=192.168.1.101:8848

  user 需要提供一个接口以供测试:

@RestController
public class TestController {

    @Autowired
    private DiscoveryClient discoveryClient;

    @RequestMapping(value = "/k8s", method = {RequestMethod.GET})
    public String insert() {
        List<ServiceInstance> list = discoveryClient.getInstances("order");

        ServiceInstance serviceInstance = list.get(0);
        URI uri = serviceInstance.getUri();
        System.out.println(uri);
        testUri(uri.toString());
        return list.toString();
    }

    public void testUri(String uri) {
        URL url = null;
        try {
            url = new URL(uri);
            URLConnection urlConnection = url.openConnection();
            urlConnection.connect();
            System.out.println("连接可用");
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

  然后查看nacos server的服务列表:

  为了验证user能够发现order的地址,访问localhost:8081/k8s,查看日志输出,从而测试是否可以ping通order地址

 (2)  本地测试无误以后将两个项目打成 jar 包,丢到 linux 目录中。编写 Dockerfile 文件:

FROM openjdk:8-jre-alpine
COPY user-1.0.0-SNAPSHOT.jar /user.jar
ENTRYPOINT ["java","-jar","/user.jar"]

-------

FROM openjdk:8-jre-alpine
COPY order-0.0.1-SNAPSHOT.jar /order.jar
ENTRYPOINT ["java","-jar","/order.jar"]

  构建镜像:

docker build -t user-image:v1.0 .
docker build -t order-image:v1.0 .

  将镜像推送到远程私人仓库:我这里选择了阿里云

#打 tag
docker tag user-image:v1.0 registry.cn-hangzhou.aliyuncs.com/wuzz-docker/user-image:v1.0
docker tag order-image:v1.0 registry.cn-hangzhou.aliyuncs.com/wuzz-docker/order-image:v1.0     
#推送
docker push registry.cn-hangzhou.aliyuncs.com/wuzz-docker/user-image
docker push registry.cn-hangzhou.aliyuncs.com/wuzz-docker/order-image 

(3) 编写  user.yaml ,order.yaml 文件:

  user.yaml

# 以Deployment部署Pod
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: user
spec: 
  selector: 
    matchLabels: 
      app: user
  replicas: 1
  template: 
    metadata:
      labels: 
        app: user
    spec: 
      containers: 
      - name: user
        image: registry.cn-hangzhou.aliyuncs.com/wuzz-docker/user-image:v1.0
        ports: 
        - containerPort: 8081
---
# 创建Pod的Service
apiVersion: v1
kind: Service
metadata: 
  name: user
spec: 
  ports: 
  - port: 80
    protocol: TCP
    targetPort: 8081
  selector: 
    app: user
---
# 创建Ingress,定义访问规则,一定要记得提前创建好nginx ingress controller
apiVersion: extensions/v1beta1
kind: Ingress
metadata: 
  name: user
spec: 
  rules: 
  - host: k8s.demo.gper.club
    http: 
      paths: 
      - path: /
        backend: 
          serviceName: user
          servicePort: 80

  order.yaml:

# 以Deployment部署Pod
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: order
spec: 
  selector: 
    matchLabels: 
      app: order
  replicas: 1
  template: 
    metadata:
      labels: 
        app: order
    spec: 
      containers: 
      - name: order
        image: registry.cn-hangzhou.aliyuncs.com/wuzz-docker/order-image:v1.0
        ports: 
        - containerPort: 9090
---
# 创建Pod的Service
apiVersion: v1
kind: Service
metadata: 
  name: order
spec: 
  ports: 
  - port: 80
    protocol: TCP
    targetPort: 9090
  selector: 
    app: order

(4) 构建 pods :kubectl apply -f user.yaml

  kubectl get pods  查看pods

  kubectl get pods -o wide   查看pods详情 

  kubectl get svc   查看service

  kubectl get ingress  查看ingress网络

   这个时候我通过:kubectl logs -f <pod-name>   [主要是为了看日志输出,证明user能否访问order] 发现这个pod报错了,连接不上,经过测试  在本地跟直接在linux上通过java -jar 运行都是可以注册的 ,没问题。

   这个时候我们可以  docker exec -it    containerId   /bin/sh  进入对用容器  ping 一下 这里报错的地址,发现 ping 不通。这个时候获取到对应的 pod 的 IP:

  在节点 192.168.190.114 增加一条路由规则:/sbin/iptables -t nat -I POSTROUTING -s 192.168.190.0/24 -j MASQUERADE

  然后会发现注册成功:

 

 

   可以发现,注册到nacos server上的服务ip地址为pod的ip,比如192.168.190.114/192.168.190.115 .

 

 (5) 测试:通过浏览器访问我们配置的 Ingress 的对应路径

  看一下 pod 的日志发现调用没问题。如果服务都是在K8s集群中,最终将pod ip注册到了nacos server,那么最终服务通过pod ip发现。

 

假如user现在不在K8s集群中,order在K8s集群中:

  比如user使用本地idea中的,order使用上面K8s中的 。

  • 启动本地idea中的user服务
  • 查看nacos server中的user服务列表
  • 访问本地的localhost:8081/ks,并且观察idea中的日志打印,发现访问的是order的pod id,此时肯定是不能进行服务调用的,怎么解决呢?

  之所以访问不了,是因为order的pod ip在外界访问不了,怎么解决呢?

  1. 可以将pod启动时所在的宿主机的ip写到容器中,也就是pod id和宿主机ip有一个对应关系
  2. pod和宿主机使用host网络模式,也就是pod直接用宿主机的ip,但是如果服务高可用会有端口冲突问题[可以使用pod的调度策略,尽可能在高可用的情况下,不会将pod调度在同一个worker中]

  我们来演示一个host网络模式的方式,修改order.yaml文件,修改之后apply之前可以看一下各个节点的9090端口是否被占用

apiVersion: apps/v1
kind: Deployment
metadata:
  name: order
spec:
  selector:
    matchLabels:
      app: order
  replicas: 1
  template:
    metadata:
      labels:
        app: order
    spec:
      #主要是加上host映射
      hostNetwork: true
      containers:
      - name: order
        image: registry.cn-hangzhou.aliyuncs.com/wuzz-docker/order-image:v1.0
        ports:
        - containerPort: 9090
---
# 创建Pod的Service
apiVersion: v1
kind: Service
metadata:
  name: order
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 9090
  selector:
    app: order

   构建之前记得把之前哪个删掉:kubectl apply -f order.yaml 

   kubectl get pods -o wide --->找到pod运行在哪个机器上,比如w2,查看w2上的9090端口是否启动

   构建完,启动本地的user服务,看是否注册上去:

 

 

  访问本地发 user服务:

 

   查看控制台的输出信息:

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