This is an implementation of a spring web mvc app that produces, consumes and streams simple Kafka Messages, when SSL authentication is involved.

Also, containers were added since in today's world almost everything lives in containers. So, a Dockerfile with security and following docker best practises for java applications, is provided.

There are 3 environments available, to test the connectivity of spring application with kafka:

1. Local (is now done using integration junit tests)
2. Docker-compose
3. Kubernetes with Helm (not tested yet)

In order to test the functionality locally, integration unit tests are provided, using JUnit. They can be found in KafkaServiceIntegrationTest Note that the kafka cluster has to be set up manually. One easy way to do it is by using docker-compose, without the kafka-producer service. Or else, the user can manually set it up.

Docker-compose is set up, to make life easier. It provides a working cluster of 3 zookeepers and 2 kafka brokers. The service is also set to use the brokers from docker-compose. Note: The test kafka certs are copied in the docker filesystem using docker-compose configuration, rather than doing it in Dockerfile

./gradlew clean build -x test
docker-compose up --build

For K8s environments, we use minikube setup to test. Also, a custom helm-plugin that provides templates needed. In build.gradle you can find tasks to publish the images to a docker repo, so that are available for k8s to download. You need to configure your own repo, so that you have access. Also, tasks to interact with k8s using Helm. You can find more info regarding using minikube with helm and how to deploy the current services in the guide provided.

List of requests to use for testing (can be simply used on browsers or any rest-client):

http://localhost:8080/kafka/kafka-producer/produce-messages
http://localhost:8080/kafka/kafka-consumer/consume-messages
http://localhost:8080/kafka/kafka-stream/process-messages
http://localhost:8080/kafka/kafka-consumer/consume-streamed-messages