JarCastingspring-cloud-heroku-registry 
Spring Cloud Discovery extension based on Heroku Private Spaces Registry.
More information about Heroku DNS registry: https://devcenter.heroku.com/articles/dyno-dns-registry
Service discovery is performed by depending on the /etc/heroku/space-topology.json file which is updated within 10 seconds of topology changes.
Usage
Depend on the following spring starter dependency:
<dependency>
<groupId>com.xt-i</groupId>
<artifactId>spring-cloud-starter-heroku-registry-discovery</artifactId>
<version>1.0.1</version>
</dependency>
Use a standard Heroku Java Procfile
web: java $JAVA_WEB_OPTS -Dserver.port=$PORT -jar target/*.jar
Configuration without client loadbalancing support
Use the following Spring annotations on your configuration class to run the application on Heroku. The embedded tomcat will both run on the $PORT used by the Heroku loadbalancer and the internally used 8080 port by processes within the Private Space. This internal port can overridden by setting the SPRING_CLOUD_HEROKU_PORT environment variable. By default a filter will run causing the /spring-cloud-heroku-metadata endpoint to be only available on the internal port.
@Configuration
@EnableDiscoveryClient
public class YourConfigClass {
@Value("${SPRING_CLOUD_HEROKU_PORT:8080}")
private String springCloudHerokuPort;
@Bean
public EmbeddedServletContainerFactory servletContainer() {
TomcatEmbeddedServletContainerFactory tomcat = new TomcatEmbeddedServletContainerFactory();
Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");
connector.setScheme("http");
connector.setPort(Integer.valueOf(springCloudHerokuPort));
tomcat.addAdditionalTomcatConnectors(connector);
return tomcat;
}
}
Configuration with client loadbalancing support (RestTemplate with Ribbon)
Depend on the following additional dependencies:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-ribbon</artifactId>
<version>1.2.0.RELEASE</version>
</dependency>
Add @EnableAutoConfiguration annotation to the configuration to register beans used by Ribbon. Also register a @LoadBalanced RestTemplate bean.
@Configuration
@EnableDiscoveryClient
@EnableAutoConfiguration
public class YourConfigClass {
@Value("${SPRING_CLOUD_HEROKU_PORT:8080}")
private String springCloudHerokuPort;
@Bean
public EmbeddedServletContainerFactory servletContainer() {
TomcatEmbeddedServletContainerFactory tomcat = new TomcatEmbeddedServletContainerFactory();
Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");
connector.setScheme("http");
connector.setPort(Integer.valueOf(springCloudHerokuPort));
tomcat.addAdditionalTomcatConnectors(connector);
return tomcat;
}
@LoadBalanced
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
}
Use the @LoadBalanced RestTemplate bean where necessary by using {processName}.{appName} as host.
@Service
public class MyService {
@Autowired
private RestTemplate restTemplate;
public void call(){
restTemplate.getForObject("http://processname.herokuapp/api/hello", String.class);
}
}
Example
https://github.com/XT-i/spring-cloud-heroku-registry-example
