kafka-openshift-streams-demo

A project that demonstrates how to run the Apache Kafka Client against a Kafka broker running under Red Hat OpenShift Streams for Apache Kafka

What you need to know before you start

• Java programming with Maven
• Access to the Red Hat OpenShift Console
• Basic understanding of message production and consumption under Kafka

Setting up a Kafka instance and a Kafka topic in Red Hat Open Shift

The first thing you will need to do is build a running instance of Kafka Streams on Red Hat OpenShift.

Follow the directions described in the interactive QuickStart document, Getting started with Red Hat OpenShift Streams for Apache in order to get an instance of Kafka Streams running in OpenShift.

You will need retrieve four fields of information that will be created when you get OpenShift Kafka Streams up and running. The information you will need is:

• The Kafka topic name that you created in Open Shift
• The URL of the Kafka Bootstrap Server
• The Client ID associated with the Service Account you will bind to the Kafka instance you created in OpenShift
• The Client Secret associated with the Service Account you will bind to the Kafka instance you created in OpenShift.

The Quickstart instructions do a good job of making it very clear as to when these fields are created. You'll want to copy the fields into a text editor so that you can paste them into the .env file you'll create the emulate environment variables and their values.

Configuring the .env file

This project uses java-dotenv that emulates environment variables and their values a runtime.

java-dotenv is already installed in the project's pom.xml file.

However, you will need to add a file named .env to the root of the project.

The structure of the .env file is as follows:

DOTENV_TEST_MESSAGE=PING
KAFKA_STREAM_TEST_TOPIC=<TOPIC_NAME_ON_KAFKA_STREAMS>
KAFKA_STREAM_USER_NAME=<SERVICE_ACCOUNT_CLIENT_ID>
KAFKA_STREAM_PWD=<SERVICE_ACCOUNT_CLIENT_SECRET>
KAFKA_STREAM_BOOTSTRAP_SERVER=<KAFKA_STREAMS_BOOTSTRAP_SERVER_URL>

WHERE

• <TOPIC_NAME_ON_KAFKA_STREAMS> is the name of topic where messages will be produced to and consumed from. The topic must be created within in Red Hat OpenShift Kafka Streams.
• <SERVICE_ACCOUNT_CLIENT_ID> is the Client ID created when you created the OpenShift Service Account bound to the stream.
• <SERVICE_ACCOUNT_CLIENT_SECRET> is the Client Secret created when you created the OpenShift Service Account bound to the stream.
• <KAFKA_STREAMS_BOOTSTRAP_SERVER_URL> is the URL of the Kafka Bootstrap which is created when you create the instance of OpenShift Kafka Streams.

EXAMPLE:

DOTENV_TEST_MESSAGE=PING
KAFKA_STREAM_TEST_TOPIC=mytopic
KAFKA_STREAM_USER_NAME=srvc-acct-7axxx530-e8fe-471c-bb3d-aa005020d911
KAFKA_STREAM_PWD=6823f7bd-649b-4029-8a1c-8713axxx918b
KAFKA_STREAM_BOOTSTRAP_SERVER=my-first-k-c-skxxxt--m--nhc-fna.bf2.kafka.rhcloud.com:443

You will substitute the values between the <...> brackets with values particular to your instance of OpenShift Kafka Streams.

Building the code

TO BE PROVIDED

Running the tests

Make sure that you've properly configured the .env file with the values that are particular to your running instance of OpenShift Kafka Streams.

Then, run the following command from the top level of the directory in which you installed the demonstration code.

mvn test

Upon success, you'll get output similar to the following:

Results :

Tests run: 4, Failures: 0, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  19.510 s
[INFO] Finished at: 2022-05-09T19:08:02Z
[INFO] ------------------------------------------------------------------------