This paper describes how a service reads files from the configuration center, and the configuration center reads configuration files from remote git. When there are many service instances, they read files from the configuration center. At this time, it can be considered to make the configuration center into a microservice and cluster it to achieve high availability. The architecture is as follows:
1, Preparations
Continue with the project from the previous article and create an Eureka server project to use as a service registry.
The introduction of Eureka in pom.xml depends on spring cloud starter Eureka server. The code is as follows:
<?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>com.forezp</groupId> <artifactId>eureka-server</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>eureka-server</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.2.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka-server</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Dalston.RC1</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> <repositories> <repository> <id>spring-milestones</id> <name>Spring Milestones</name> <url>https://repo.spring.io/milestone</url> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> </project>
On the configuration file application.yml, specify 8889 as the service port, and as the basic configuration of the service registry, the code is as follows:
server: port: 8889 eureka: instance: hostname: localhost client: registerWithEureka: false fetchRegistry: false serviceUrl: defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
Entrance class:
@EnableEurekaServer @SpringBootApplication public class EurekaServerApplication { public static void main(String[] args) { SpringApplication.run(EurekaServerApplication.class, args); } }
2, Transform config server
In its pom.xml file and EurekaClient's start-up depends on spring cloud starter Eureka, the code is as follows
<dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-config-server</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> </dependencies>
The configuration file application.yml specifies that the service registration address is http://localhost:8889/eureka /. For other configurations, please refer to the same article. The complete configuration is as follows:
spring.application.name=config-server server.port=8888 spring.cloud.config.server.git.uri=https://github.com/forezp/SpringcloudConfig/ spring.cloud.config.server.git.searchPaths=respo spring.cloud.config.label=master spring.cloud.config.server.git.username= your username spring.cloud.config.server.git.password= your password eureka.client.serviceUrl.defaultZone=http://localhost:8889/eureka/
The configuration file application.yml specifies that the service registration address is http://localhost:8889/eureka /. For other configurations, please refer to the same article. The complete configuration is as follows:
spring.application.name=config-server server.port=8888 spring.cloud.config.server.git.uri=https://github.com/forezp/SpringcloudConfig/ spring.cloud.config.server.git.searchPaths=respo spring.cloud.config.label=master spring.cloud.config.server.git.username= your username spring.cloud.config.server.git.password= your password eureka.client.serviceUrl.defaultZone=http://localhost:8889/eureka/
Finally, you need to add the @ EnableEureka annotation to the Application class of the program.
3, Transform config client
To register it to the service registry, as the Eureka client, pom file and spring cloud starter Eureka are required. The code is as follows:
spring.application.name=config-server server.port=8888 spring.cloud.config.server.git.uri=https://github.com/forezp/SpringcloudConfig/ spring.cloud.config.server.git.searchPaths=respo spring.cloud.config.label=master spring.cloud.config.server.git.username= your username spring.cloud.config.server.git.password= your password eureka.client.serviceUrl.defaultZone=http://localhost:8889/eureka/
Configuration file bootstrap.properties, note that it is bootstrap. Plus the service registration address is http://localhost:8889/eureka/
spring.application.name=config-client spring.cloud.config.label=master spring.cloud.config.profile=dev #spring.cloud.config.uri= http://localhost:8888/ eureka.client.serviceUrl.defaultZone=http://localhost:8889/eureka/ spring.cloud.config.discovery.enabled=true spring.cloud.config.discovery.serviceId=config-server server.port=8881
spring.cloud.config.discovery.enabled is to read files from the configuration center.
spring.cloud.config.discovery.serviceId the servieId of the configuration center, which is the service name.
It is found that when reading the configuration file, the ip address is no longer written, but the service name. At this time, if the configuration service is deployed in multiple copies, it can be highly available through load balancing
Start Eureka servr, config server, config client
Visit: http://localhost:8889/
Insert picture description here
Visit http://localhost:8881/hi, the browser shows:
foo version 3
