Container 2 Container Networking on PWS CloudFoundry

Requirements

• Pivotal Web Services account
• Feature c2c enabled on PWS
• Feature SCS (Spring Cloud Services) enabled on PWS
• CloudFoundry CLI
• SpringBoot CLI + Spring Cloud CLI

Run the example locally

Service Registry & Circuit Breaker Dashboard

Start both an Eureka & Hystrix Dashboard instances with Spring Cloud CLI

spring cloud eureka hystrixdashboard

Compile and run the example

# Compiles both services
$ mvn clean package

# Starts the downstream service
$ cd travel-service
$ mvn spring-boot:run

# Starts the client
$ cd travel-client
$ mvn spring-boot:run

You can start the apps from your IDE or a terminal.

Test it

Open the url http://localhost:8761 in a browser, you will see the 2 services registered in Eureka.

Click on the travel-client and open the /destinations endpoint, you will receive a list of destinations coming from the downstream service travel-service.

Run the example on the PWS CloudFoundry

Service Registry

On PWS, go to the marketplace and create a Service Registry service.

Circuit Breaker

On PWS, go to the marketplace and create a Circuit Breaker service.

Build and Deploy

$ mvn clean package
$ cf push

Allow c2c communication

Once the 2 applications are deployed and running, you cannot access the travel-service from the travel-client. You must allow the connection with the following command:

$ cf add-network-policy travel-client --destination-app travel-service --protocol tcp --port 8080

Test it

In the Service Registry service, you will see your 2 registered apps.

Try to query the travel-client destinations endpoints. The route is set to generate a random url, so you will have to get it from your environment.

What's new if you have existing code

New dependency

You have to add this two new dependencies into your pom.xml file:

<!-- Replacement for spring-cloud-starter-eureka -->
<dependency>
    <groupId>io.pivotal.spring.cloud</groupId>
    <artifactId>spring-cloud-services-starter-service-registry</artifactId>
    <version>1.4.1.RELEASE</version>
</dependency>

<!-- Replacement for spring-cloud-starter-hystrix -->
<dependency>
    <groupId>io.pivotal.spring.cloud</groupId>
    <artifactId>spring-cloud-services-starter-circuit-breaker</artifactId>
    <version>1.4.1.RELEASE</version>
</dependency>

Direct registration in the properties

To register to SCS Eureka, you have to register with the direct method:

spring:
  cloud:
    services:
      registrationMethod: direct

By default Hystrix will not be enabled when using Feign. You can declare a Bean for HystrixFeign.builder() or simply turn it on via the following property:

feign:

  hystrix:

    enabled: true


Set the TRUST_CERTS environment variable

To be able to register to the Service Registery service on PWS, you need a using a self-signed SSL certificate. To do so, you have to set a TRUST_CERTS environment variable per application. You can use the one in my manifest.yml deployment file or the following command line:

$ cf set-env travel-client TRUST_CERTS api.run.pivotal.io
$ cf set-env travel-service TRUST_CERTS api.run.pivotal.io

NOTE

Using the Spring Cloud Services Starters for Service Registry will make all application endpoints secured. You should use your own authentication system or disable it like I did in my examples (NOT recommended) with:

security:
  basic:
    enabled: false

More Details on my blog

If you want to learn more, check out my blog

References

Thanks to this Pivotal blog post that helped me getting started.