Testing Microservices with Skyramp in IntelliJ IDEA

Test Your Microservices with Skyramp in IntelliJ IDEA

Hello devs! This is Dan from Skyramp. When we say Skyramp meets devs in any workflow, we mean it. In this blog, we will demonstrate iterative testing and development for microservices in a local Kubernetes cluster performed directly from the IntelliJ IDEA with Skyramp. It’s as easy as 1, 2, 3.

What Are We Testing?

This blog features the Skyramp fork of Google’s popular cloud-native microservices demo app, Online Boutique. Online Boutique is a web-based e-commerce app containing microservices that mimic real-world services, such as a product catalog, shopping cart, ad service, recommendation service, payment service, and others. The services use gRPC APIs by default, but Skyramp has also added support for REST and Thrift APIs.

This walkthrough will focus on the ad service component of the system to demonstrate how you can easily generate test descriptions and run tests during the development stage using Skyramp. The ad service is a microservice written in Java, so IntelliJ IDEA is a perfect fit for our development environment.

Pre-Flight Checklist

Here’s what you need in order to follow along with this walkthrough:

• Install Docker

• Install the Skyramp Terminal Client

• Install JetBrains IntelliJ IDEA and download a JDK

• Clone the Skyramp project, sample-microservices, to a folder of your choice. From a terminal, run:

git clone https://github.com/letsramp/sample-microservices.git

Let’s Get Testing

First, start the IntelliJ IDEA you installed and open the Skyramp sample-microservices project from the local folder where it was cloned. Navigate to the src/adservice/src/main/java/hipstershop folder and open the AdService.java file to view the ad service source code.

Next, open the Terminal pane in the IDE by clicking the Terminal button in the lower left corner. You can run all the skyramp commands from this Terminal. Change to the Skyramp demo directory for gRPC in the terminal and check your installed version of skyramp:

cd skyramp/grpc-demo
skyramp version

At this point, you should see something like this:

Next, we will create a local Kubernetes cluster for deploying and testing the microservices. This is easily done with the Skyramp client:

skyramp cluster create --local

Deploy all the services to the cluster that will make up our system under test using Skyramp Deployer:

skyramp deployer up grpc-app

Once the services are deployed, you can check the status of the services, also with Skyramp Deployer:

skyramp deployer status

Now we will generate a test description for the ad service using Skyramp Tester. This will allow us to execute tests against the running service.

skyramp tester generate --protocol protobuf \
--api-schema pb/demo.proto --alias ad-service \
--port 9555 --proto-service AdService

How do you know what values to provide to Skyramp Tester in order to generate a test description? In this case, we know we will be using protobuf as the protocol for our distributed application. We already have a proto file defined in the repo at pb/demo.proto, so we can utilize that for the api-schema flag. The AdService is specified in the proto file, which is the service we want to test, so that should be used for the proto-service flag. The values for the alias and port flags are derived from the deployment status as seen in the screenshot above.

Once you run the Skyramp Tester command above, the generated test description file will be under the tests folder called ad-service.yaml. Next, we simply need to define our specific scenario for testing.

The ad service behavior we want to test is whether the service returns exactly two ads from its response payload, and if those ads are non-zero length. Furthermore, we want to test that the two ads are not the same, because we do not want duplicate ads returned. We can define all of this by adding a scenarios section with asserts in the file as seen below:

Here is the scenario section with the asserts to add to the YAML file if you would like to copy and paste:

scenarios:
 - name: scenario1
   steps:
     - request: EAdServiceMGetAds
     - asserts: requests.EAdServiceMGetAds.res.ads.length == 2
     - asserts: requests.EAdServiceMGetAds.res.ads[0].text.length >= 1
     - asserts: requests.EAdServiceMGetAds.res.ads[1].text.length >= 1
     - asserts: requests.EAdServiceMGetAds.res.ads[0].text != requests.EAdServiceMGetAds.res.ads[1].text

Now save the file. Running the test is easy with Skyramp Tester. From the same skyramp/grpc-demo directory, just execute:

skyramp tester start ad-service -n test-grpc-demo

Notice from the test results that the first three asserts passed, but the last assert failed. We appear to be getting duplicate ads from our ad service. A side note: this failed test may take several tries to surface, since the ads returned are randomized and may not always be the same.

If we navigate back to the source file and examine the code, we see that getRandomAds() does not account for duplicates.

We can fix that with a LinkedHashSet to force uniqueness. Here is the new getRandomAds() source with a few lines changed:

private List<Ad> getRandomAds() {
  List<Ad> ads = new ArrayList<>(MAX_ADS_TO_SERVE);
  Collection<Ad> allAds = adsMap.values();
  Set<Ad>set = new LinkedHashSet<Ad>();
  while (set.size() < MAX_ADS_TO_SERVE) {
    set.add(Iterables.get(allAds, random.nextInt(allAds.size())));
  }
  ads.addAll(set);
  return ads;
}

We update the code in the editor and then rebuild the ad service from src/adservice in a new terminal pane by running:

cd src/adservice
./gradlew installDist

Once the ad service is rebuilt, simply bring all the services down and back up again with Skyramp Deployer:

skyramp deployer down grpc-app
skyramp deployer up grpc-app

Now, when you re-run the test with Skyramp Tester, all asserts will pass because the ad service no longer produces duplicate ads in the payload.

skyramp tester start ad-service -n test-grpc-demo

Once you are finished with your test session, you can remove the test cluster completely with Skyramp:

skyramp deployer down grpc-app 
skyramp cluster remove --local

Wrapping Up

And there you have it. You can use this setup to explore more capabilities Skyramp provides with Mocker, Tester, and Deployer. We give you all the tools you need to mock, test, and deploy your own microservices from IntelliJ IDEA easily with Skyramp.

Happy testing!

Have questions or comments? Join the Skyramp Community Discord.