Using Spring cloud consul.

Registering spring boot applications with spring boot using spring cloud consul.

Service discovery can be achieved via Consul.(https://www.consul.io/)

Spring boot application can register with Consul using spring-cloud-consul.(https://cloud.spring.io/spring-cloud-consul/)

You can set up consul by installing it or if you use docker you can set it up via the command docker run -p 8500:8500 consul:0.8.5

If you set it up via docker you can go to http://localhost:8500/ui/#/dc1/services and you should see

Now we will set up two spring boot webservices

• Pet Service
• Pet Client

They both register with consul when we include the dependency

<dependency>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>

Consul needs some health checks to pass for these services to register successfully, so we include spring-boot-actuator to provide these health checks

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

After this you should see the services registered in Consul.

AddingMake sure you add the annotation

@EnableDiscoveryClient

Once this is all set up the client can talk to the service via service discovery.

  @GetMapping("/{name}")
    public String[] getPets(@PathParam("name") String petName)
    {
        ServiceInstance serviceInstance=client.getInstances("pet-service")
                .stream().findFirst().
                        orElseThrow(()-> new RuntimeException("pet-service not found"));

        String url = serviceInstance.getUri().toString()+ "/pets/"+petName;
        return restTemplate.getForObject(url,String[].class);
    }

And walla, you are all done. All code can be found at https://github.com/arnabmitra/Consul-demo