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Services description

Let’s understand the environment we currently have and take a look at the deployed services.

To see the pods you can either look at the OpenShift Console or use oc get deployment -n retail.

These are the 11 services currently deployed:

Service

Type

Description

cashback-db

Persistence

PostgreSQL database for cashback related information.

retail-db

PostgreSQL database used by the legacy services;

kafka-connect-connect

Integration

Kafka connectors for database event streaming (debezium);

cashback-connector

Camel + Quarkus service for event-driven processing of expenses and customers;

elastic-connector

Camel + Quarkus service for event-driven synchronization of product data with ElasticSearch;

sales-streams

Quarkus + Kafka Streams event-driven service for purchase data (sales data) aggregation and synchronization;

cashback-service

Quarkus + Camel event-driven service responsible for calculating and maintaining cashback data up-to-date in the new database;

retail-simulation

Data simulation

a Quarkus application that allows simulating a pre-selected number of purchases in the retail database;

kafdrop

Data Visualization

a kafka client ui to facilitate the visualization of events and topics;

cashback-ui

Quarkus + Panache back-end service to facilitate the visualization of cashback information;

search-service

Quarkus + ElasticSearch extension to simplify the visualization of the indexed data residing in elastic search;

Components configuration

All the customization of the services is externalized using OpenShift secrets. As an example, let’s check the connection information for the cashback-connector service.

  1. Navigating to Workloads → Deployments → cashback-connector ⇒ YAML, the following configuration section can be visualized:

    cashback connector deployment configuration

  2. In order to find out exactly which configuration values are being used by the cashback-connector service, let’s take a look at the configured secret. On the left menu navigate to Workloads → Secrets

  3. In the filter, search by the name cashback-connector and select the secret:

    cashback connector secret

  4. Scroll to the bottom of the page and click on Reveal values, located in the Data section.

    • The parameters you used in your Ansible provisioning inventory was used by Helm charts in order to generate these final values, which are a mix of default template values, plus your custom configuration.

    • This service is configured to:

      • Connect to the Kafka bootstrap server;

      • Subscribe to the topics retail.sale-aggregated and retail.updates.public.customer;

      • Be a publisher of events on the topic retail.expense-event;

      • Connect to the cashback-db, a postgresql database;

Additional information

Kafka Connect - Debezium installation

Debezium is provisioned on the cluster using Helm and the Strimzi operator.

kafka connect