Spring Cloud Practice Part 1 - Discovery and Config
2016, Nov 02
Discovery and Config
Eureka
Discovery First, Config will register itself to Eureka. The rest service like Api service will not have application.yml which will be loaded form Config service.
build.gradle
...
buildscript {
ext {
springBootVersion = '1.4.0.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
classpath "io.spring.gradle:dependency-management-plugin:0.5.6.RELEASE"
}
}
....
apply plugin: "io.spring.dependency-management"
dependencyManagement {
imports {
mavenBom 'org.springframework.cloud:spring-cloud-netflix:1.3.0.BUILD-SNAPSHOT'
}
}
...
dependencies {
compile ('org.springframework.cloud:spring-cloud-starter-eureka-server')
}
Spring Boot Applicaiton
@SpringBootApplication
@EnableEurekaServer
public class DiscoveryApplication {
public static void main(String[] args) {
SpringApplication.run(DiscoveryApplication.class, args);
}
}
application.yml
spring:
application:
name: discovery
server:
port: 8761
eureka:
instance:
prefer-ip-address: true // if run on docker or cloud,
// no dns support, should use ip address for service.
client:
registerWithEureka: false
fetchRegistry: false
server:
waitTimeInMsWhenSyncEmpty: 0
Spring Cloud Config
build.gradle
... // same setting as Eureka
dependencies {
compile('org.springframework.cloud:spring-cloud-config-server')
compile("org.springframework.cloud:spring-cloud-starter-eureka")
...
}
MainApplication.java
Spring Boot Application
@SpringBootApplication
@EnableAutoConfiguration
@EnableConfigServer
@EnableEurekaClient
public class ConfigApplication {
public static void main(String[] args) {
SpringApplication.run(ConfigApplication.class, args);
}
}
bootstrap.yml
spring:
application:
name:config <= will be referred by other service.
eureka:
instance:
prefer-ip-address: true
leaseExpirationDurationInSeconds: 2
leaseRenewalIntervalInSeconds: 1
client:
serviceUrl:
defaultZone: http://${EUREKA_HOST:localhost}:${EUREKA_PORT:8761}/eureka/
application.yml
server:
port: 8888 <= will be registered in Eureka
logging:
level:
com.netflix.discovery: 'OFF'
org.springframework.cloud: 'DEBUG'
spring:
cloud:
config:
server:
git:
uri: https://github/systembugtj/sample-config.git <= A git url
searchPaths: appconfig <= folder in the git
username: user
password: password
git structure.
For example, have a RESTful API service named api. Then should have below file under appconfig for difference profile like uat/dev/preprod/prod .etc
app-uat.yml app-dev.yml app-prod.yml
Sample Api Service to use Eureka and Config
###build.gradle
... // same setting as Eureka
dependencies {
compile('org.springframework.cloud:spring-cloud-config-server')
compile("org.springframework.cloud:spring-cloud-starter-eureka")
...
}
Spring Boot Application
@SpringBootApplication
@EnableConfigServer
@EnableEurekaClient
@RestController
public class ApiApplication {
public static void main(String[] args) {
SpringApplication.run(ConfigApplication.class, args);
}
@RequestMap ("/hello")
public String hello() {
return "hello";
}
}
bootstrap.yml
spring:
application:
name: api
profiles:
active: ${RUNNING_ENV:dev} <= profile name
cloud:
config:
discovery:
enabled: true
serviceId: config <= name used by spring cloud config.
eureka:
instance:
prefer-ip-address: true
leaseExpirationDurationInSeconds: 2
leaseRenewalIntervalInSeconds: 1
client:
serviceUrl:
defaultZone: http://${EUREKA_HOST:localhost}:${EUREKA_PORT:8761}/eureka/