Event driven applications with Serverless Knative Eventing - Instructions

Gain understanding of what has been already setup for you

Deploy the Quarkus Knative Services needed for the solution

Build an event mesh with OpenShift Serverless Eventing components

Try out the solution end-to-end to see how data flows through the various systems and services

In a browser window, navigate to the {openshift_cluster_console}[OpenShift console, window="console"]. If needed, login with your username and password ({user_name}/{user_password}).
If this is the first time you open the console, you will be directed to the Developer Perspective of the console, which shows you the different namespaces you have access to.

Click on the globex-serverless-{user_name} namespace link to select the namespace you are going to use in this lab, and select Topology from the left menu.

The Topology view displays the components that have been setup for you already. Note that this screenshot shows the topology after the components have been moved around to be displayed well here.

Let us look at a few of the current components. The rest of the components are discussed in the next sections

There are 3 Knative Services that are used in this solution

Navigate to the OpenShift Console’s Administrator view, and go to Serverless > Serving menu. You will see that two of the above mentioned services have been already deployed (aiml-moderate-reviews and aiml-sentiment-reviews).
In the next step, you will create the persist-reviews Knative service using a Custom Resource Definition (CRD).

Create persist-reviews: Click on the Create button highlighted in the screenshot above. Choose Create > Service option. Replace all existing content with the following YAML file, and click on Save

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: persist-reviews
  namespace: globex-serverless-{user_name}
spec:
  template:
    metadata:
      annotations:
        autoscaling.knative.dev/min-scale: "1"
    spec:
      containers:
        - image: quay.io/globex-sentiment-analysis/persist-reviews:latest
          volumeMounts:
            - mountPath: /deployments/config
              name: config
              readOnly: true
      volumes:
        - name: config
          secret:
            secretName: persist-reviews

Navigate back to the {openshift_cluster_console}/topology/ns/globex-serverless-{user_name}?view=graph[Developer > Topology, window="console", target="console"] view of the globex-serverless-{user_name} namespace and you will notice all the three Knative services

A few interesting points to notes with the newly created persist-reviews

You have now completed the setup of all the components needed. Navigate to {openshift_cluster_console}/topology/ns/globex-serverless-{user_name}?view=graph[Topology View, window="console"] to view the final topology.

To open the Globex web application, click on the symbol next to the globex-web deployment in the topology view.

Click on the Login link on the top-right corner of the home page

You will be navigated to the Keycloak login page

Login using any of the following usernames. The password is openshift for all these users.

Click on the Cool Stuff Store link on the top-menu to view the list of products available

Click on any product to view the details page.

Type a review comment and click on Submit.

If the review comment is appropriate it will then appear in the same page after a few seconds.

In the OpenShift Developer> Topology view, you will also notice that the Knative services have all turned fully blue because they have been triggered by the reviews submission and so have scaled up.
In a few seconds two of them (except persist-reviews) will go back to a white ring denoting that they have been scaled down to zero since they are not in use anymore.

Now, go ahead and leave review comments of as many products as you like. If you are feeling adventurous you can try a few inappropriate comments too to see how they are being moderated ;)