In your Kafka distribution, navigate to the config/ directory.

Create a file called app-services.properties.

In the app-services.properties file, set the SASL connection mechanism and the Kafka instance client credentials as shown in the following configuration. Replace the values with your own credential information. OpenShift Streams for Apache Kafka supports the SASL/OAUTHBEARER mechanism for authentication, which is the recommended authentication mechanism to use.

sasl.mechanism=OAUTHBEARER
security.protocol=SASL_SSL

sasl.oauthbearer.token.endpoint.url= https://sso.redhat.com/auth/realms/redhat-external/protocol/openid-connect/token

sasl.jaas.config=org.apache.kafka.common.security.oauthbearer.OAuthBearerLoginModule required \
  scope="openid" \
  clientId="<client-id>" \
  clientSecret="<client-secret>" ;

sasl.login.callback.handler.class=org.apache.kafka.common.security.oauthbearer.secured.OAuthBearerLoginCallbackHandler

Save the file. You’ll use this file in the next task to connect to your Kafka instance and produce messages.

On the command line, navigate to the bin/ directory of your Kafka distribution.

Use the kafka-topics script to create a Kafka topic, as shown in the following example. The example creates a topic called my-other-topic with the default settings. Replace <bootstrap_server> with the bootstrap server endpoint for your own Kafka instance.

$ ./kafka-topics.sh --create --topic my-other-topic --partitions 1 --replication-factor 3 --bootstrap-server <bootstrap_server> --command-config ../config/app-services.properties

Start the kafka-console-producer script, as shown in the following example. The example uses the SASL/OAUTHBEARER authentication mechanism with the credentials that you saved in the app-services.properties file. The command prepares a producer to send messages to the my-other-topic topic that you previously created.

$ ./kafka-console-producer.sh --topic my-other-topic --bootstrap-server "<bootstrap_server>" --producer.config ../config/app-services.properties

With the kafka-console-producer script running, enter messages that you want to produce to the Kafka topic.

>First message
>Second message
>Third message

Keep the producer running so that you can use it again later, when you create a consumer.

Open a second terminal window or tab, separate from the producer.

On the command line, navigate to the bin/ directory of your Kafka distribution.

Start the kafka-console-consumer script, as shown in the following example. The example uses the SASL/OAUTHBEARER authentication mechanism with the credentials that you saved in the app-services.properties file. The command consumes and displays messages from the my-other-topic topic.

$ ./kafka-console-consumer.sh --topic my-other-topic --bootstrap-server "<bootstrap_server>" --from-beginning --consumer.config ../config/app-services.properties

First message
Second message
Third message

If your producer is still running in a separate terminal, continue entering messages in the producer terminal and observe the messages being consumed in the consumer terminal.

Verify that the kafka-console-consumer script is running without any errors in the terminal.

Verify that the kafka-console-consumer script displays the messages from the my-other-topic example topic.