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第 67 章 Spring Cloud with Kubernetes
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第 67 章 Spring Cloud with Kubernetes

目录

67.1. Config
67.1.1. Maven 依赖
67.1.2. Spring Cloud 配置文件
67.1.3. 程序文件
67.1.4. Kubernetes 编排脚本
67.1.5. 测试
67.2. 注册发现
67.2.1. Maven 父项目
67.2.2. provider
67.2.3. consumer
67.2.4. 测试
67.2.5.

67.1. Config

Spring Cloud 使用 Kubernetes 提供的 Config Maps 作为配置中心。这样的好处是我们无需再启动一个 config 服务。

67.1.1. Maven 依赖

父项目

		
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>cn.netkiller</groupId>
	<artifactId>kubernetes</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>pom</packaging>

	<name>kubernetes</name>

	<url>http://www.netkiller.cn</url>
	<description>Spring Cloud with Kubernetes</description>

	<organization>
		<name>Netkiller Spring Cloud 手札</name>
		<url>http://www.netkiller.cn</url>
	</organization>

	<developers>
		<developer>
			<name>Neo</name>
			<email>netkiller@msn.com</email>
			<organization>Netkiller Spring Cloud 手札</organization>
			<organizationUrl>http://www.netkiller.cn</organizationUrl>
			<roles>
				<role>Author</role>
			</roles>
		</developer>
	</developers>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<spring-cloud.version>Hoxton.SR8</spring-cloud.version>

		<docker.registry>registry.netkiller.cn:5000</docker.registry>
		<docker.registry.name>netkiller</docker.registry.name>
		<docker.image>mcr.microsoft.com/java/jre:15-zulu-alpine</docker.image>
	</properties>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.3.4.RELEASE</version>
		<relativePath />
	</parent>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>${spring-cloud.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-actuator</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<modules>
		<module>service</module>
		<module>ConfigMaps</module>
	</modules>

</project>

项目模块

		
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>cn.netkiller</groupId>
		<artifactId>kubernetes</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</parent>
	<groupId>cn.netkiller</groupId>
	<artifactId>configmaps</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>configmaps</name>
	<url>http://maven.apache.org</url>
	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-kubernetes-config</artifactId>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
				<executions>
					<execution>
						<goals>
							<goal>repackage</goal>
						</goals>
					</execution>
				</executions>
			</plugin>
			<plugin>
				<groupId>com.spotify</groupId>
				<artifactId>docker-maven-plugin</artifactId>
				<version>1.2.2</version>
				<configuration>
					<imageName>${docker.registry}/${docker.registry.name}/${project.artifactId}</imageName>
					<baseImage>${docker.image}</baseImage>
					<maintainer>netkiller@msn.com</maintainer>
					<volumes>/tmp</volumes>
					<workdir>/srv</workdir>
					<exposes>8080</exposes>
					<env>
						<JAVA_OPTS>-server -Xms128m -Xmx256m</JAVA_OPTS>
					</env>
					<entryPoint>["sh", "-c", "java ${JAVA_OPTS} -jar /srv/${project.build.finalName}.jar ${SPRING_OPTS}"]</entryPoint>
					<resources>
						<resource>
							<targetPath>/srv</targetPath>
							<directory>${project.build.directory}</directory>
							<include>${project.build.finalName}.jar</include>
						</resource>
					</resources>
					<!-- <image>${docker.image.prefix}/${project.artifactId}</image> -->
					<!-- <newName>${docker.image.prefix}/${project.artifactId}:${project.version}</newName> -->
					<!-- <serverId>docker-hub</serverId> -->
					<registryUrl>http://${docker.registry}/v2/</registryUrl>
					<imageTags>
						<!-- <imageTag>${project.version}</imageTag> -->
						<imageTag>latest</imageTag>
					</imageTags>
				</configuration>
			</plugin>
		</plugins>
	</build>

</project>

67.1.2. Spring Cloud 配置文件

src/main/resources/bootstrap.yml

		
spring:
  application:
    name: spring-cloud-kubernetes-configmaps
  profiles:
    active: dev
  cloud:
    kubernetes:
      reload:
        enabled: true
        mode: polling
        period: 5000
      config:
        sources:
          - name: ${spring.application.name}
            group: cn.netkiller
            namespace: default

management:
  security:
    enabled: false
  #context-path: /
  endpoints:
    web:
      exposure:
        include: refresh

67.1.3. 程序文件

SpringBootApplication 启动文件
			
package cn.netkiller.config;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class App {
	public static void main(String[] args) {
		System.out.println("Hello World!");
		SpringApplication.run(App.class, args);
	}
}
配置类
			
package cn.netkiller.config;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;

@Configuration
@ConfigurationProperties(prefix = "greeting")
public class KeyValueConfig {
	private String message = "This is a default message";

	public String getMessage() {
		return this.message;
	}

	public void setMessage(String message) {
		this.message = message;
	}
}
控制器
			
package cn.netkiller.config;

import java.text.SimpleDateFormat;
import java.util.Date;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@EnableConfigurationProperties(KeyValueConfig.class)
@RefreshScope
public class TestController {
	@Autowired
	private KeyValueConfig keyValueConfig;

	@GetMapping("/")
	public String index() {
		return "Hello world\r\n";
	}

	@GetMapping("/hello")
	public String hello() {
		return keyValueConfig.getMessage() + " [" + new SimpleDateFormat().format(new Date()) + "]";
	}
}

67.1.4. Kubernetes 编排脚本

config.yaml

		
apiVersion: v1
kind: Service
metadata:
  annotations:
    fabric8.io/git-commit: 729badc5e8578b67c1f9387ac0d1949b0646a991
    fabric8.io/git-branch: master
    fabric8.io/git-url: https://netkiller@github.com/netkiller/spring-cloud-kubernetes.git
    fabric8.io/scm-url: https://github.com/spring-projects/spring-boot/kubernetes/ConfigMaps
    fabric8.io/scm-tag: HEAD
    prometheus.io/port: "9779"
    prometheus.io/scrape: "true"
  labels:
    expose: "true"
    app: ConfigMaps
    provider: fabric8
    version: 0.0.1-SNAPSHOT
    group: cn.netkiller
  name: config
spec:
  ports:
  - name: http
    port: 8080
    protocol: TCP
    targetPort: 8080
  selector:
    app: ConfigMaps
    provider: fabric8
    group: cn.netkiller
  type: NodePort
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: spring-cloud-kubernetes-configmaps
data:
  application.yml: |-
    greeting:
      message: Say Hello to the World
    farewell:
      message: Say Goodbye
    ---
    spring:
      profiles: development
    greeting:
      message: Say Hello to the Developers
    farewell:
      message: Say Goodbye to the Developers
    ---
    spring:
      profiles: production
    greeting:
      message: Say Hello to the Ops
---
apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    fabric8.io/git-commit: 729badc5e8578b67c1f9387ac0d1949b0646a991
    fabric8.io/git-branch: master
    fabric8.io/git-url: https://netkiller@github.com/netkiller/spring-cloud-kubernetes.git
    fabric8.io/scm-url: https://github.com/spring-projects/spring-boot/kubernetes/ConfigMaps
    fabric8.io/scm-tag: HEAD
  labels:
    app: ConfigMaps
    provider: fabric8
    version: 0.0.1-SNAPSHOT
    group: cn.netkiller
  name: config
spec:
  replicas: 1
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: ConfigMaps
      provider: fabric8
      group: cn.netkiller
  template:
    metadata:
      annotations:
        fabric8.io/git-commit: 729badc5e8578b67c1f9387ac0d1949b0646a991
        fabric8.io/git-branch: master
        fabric8.io/scm-tag: HEAD
        fabric8.io/git-url: https://netkiller@github.com/netkiller/spring-cloud-kubernetes.git
        fabric8.io/scm-url: https://github.com/spring-projects/spring-boot/kubernetes/ConfigMaps
      labels:
        app: ConfigMaps
        provider: fabric8
        version: 0.0.1-SNAPSHOT
        group: cn.netkiller
    spec:
      containers:
      - env:
        - name: KUBERNETES_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        image: registry.netkiller.cn:5000/netkiller/configmaps:latest
        #imagePullPolicy: IfNotPresent
        name: spring-boot
        ports:
        - containerPort: 8080
          name: http
          protocol: TCP
        - containerPort: 9779
          name: prometheus
          protocol: TCP
        - containerPort: 8778
          name: jolokia
          protocol: TCP
        securityContext:
          privileged: false

67.1.5. 测试

编译并构建 Docker 镜像

		
iMac:ConfigMaps neo$ mvn package docker:build

查看镜像是否正确产生

		
iMac:ConfigMaps neo$ docker images 
REPOSITORY                                        TAG                 IMAGE ID            CREATED             SIZE
registry.netkiller.cn:5000/netkiller/configmaps   latest              93280aec434f        4 minutes ago       219MB

上传镜像到私有库

		
iMac:ConfigMaps neo$ docker push registry.netkiller.cn:5000/netkiller/configmaps
The push refers to repository [registry.netkiller.cn:5000/netkiller/configmaps]
f56e553c8b82: Pushed 
7c1edc21f93f: Layer already exists 
50644c29ef5a: Layer already exists 
latest: digest: sha256:3ef48e858254ee4d578fe1737fd948b2679c33d28d0dc573cf1e8076d0a054a1 size: 952

开启 Spring cloud 访问 Kubernetes Config Maps 的权限。

		
kubectl create clusterrolebinding permissive-binding \
  --clusterrole=cluster-admin \
  --user=admin \
  --user=kubelet \
  --group=system:serviceaccounts

部署镜像

		
iMac:ConfigMaps neo$ kubectl create -f config.yaml 
service/config created
configmap/spring-cloud-kubernetes-configmaps created
deployment.apps/config created

查看服务地址

		
iMac:ConfigMaps neo$ minikube service list
|----------------------|---------------------------|--------------|----------------------------|
|      NAMESPACE       |           NAME            | TARGET PORT  |            URL             |
|----------------------|---------------------------|--------------|----------------------------|
| default              | config                    | http/8080    | http://192.168.64.12:30662 |
| default              | kubernetes                | No node port |
| kube-system          | kube-dns                  | No node port |
| kubernetes-dashboard | dashboard-metrics-scraper | No node port |
| kubernetes-dashboard | kubernetes-dashboard      | No node port |
|----------------------|---------------------------|--------------|----------------------------|

访问地址，从 Config Maps 中获取配置项。

		
iMac:ConfigMaps neo$ curl http://192.168.64.12:30662/hello
Say Hello to the World [10/7/20, 11:25 AM]

修改配置增加了=*=，然后使用 kubectl apply -f config.yaml 刷新

		
iMac:ConfigMaps neo$ curl http://192.168.64.12:30662/hello
Say Hello to the World=*= [10/7/20, 11:26 AM]

配置刷新成功

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第 66 章 Spring Cloud Sleuth 起始页 67.2. 注册发现