This demo shows how to deploy Debezium on a developer OpenShift instance using CodeReady Containers. The deployment leverages the Strimzi project, which aims to simplify the deployment of Apache Kafka on Kubernetes by means of custom resources.

• Installed and running CodeReady Containers.
• To keep containers separated from other workloads on the cluster, create a dedicated project for this example. In the remainder of this document, the debezium-example namespace will be used:

oc new-project debezium-example

Strimzi operator has to be deployed into the OpenShift cluster as the first step. In the OperatorHub tab select Strimzi and click on install button. Alternatively, you can install it from the command line:

oc create -f strimzi-kafka-operator.yaml

Once the Strimzi operator is deployed, we can deploy Kafka cluster into our project:

oc create -f kafka.yaml

To allow Debezium Kafka connector to connect to the database, we will have to provide the database credentials to the connector. For security reasons, it's a good practice not to provide the credentials directly, but keep them in a separate secured place. OpenShift provides Secret object for this purpose. Let's create one with database credentials:

oc create -f secret.yaml

Besides that, we have to also create a role which is allowed to read this secret:

oc create -f role.yaml

In the next step, we will create Kafka Connect cluster. Besides creating the cluster itself, Strimzi does couple of other things. It also creates a service account for this cluster. To allow Kafka Connect to access our secret, we have to bind Kafka Connect service account to the role created in previous step, which is allowed read the secret:

oc create -f role-binding.yam

Now, we have all reparation steps done and can deploy source database and Kafka Connect cluster.

As a data source, MySQL will be used in this example. Besides running a pod with MySQL database, an appropriate service which will point to the pod with DB itself is needed. It can be created e.g. as follows:

oc create -f mysql.yaml

To be able to deploy Kafka Connect into the cluster, we have to first create its image with the appropriate Debezium plugin (MySQL in this case). However, Strimzi allows to merge image build with deployment itself, so we can do it at once:

oc create -f kafka-connect.yaml

Kafka Connect image with Debezium plugin is built and pushed into the internal OpenShift repository. Afterwards, Kafka Connect is deployed from this image into the cluster.

As the last step we have to create Debezium connector for MySQL database:

oc apply -n debezium-example -f kafka-connector.yaml

As you can notice, we are not providing credential to the database directly in the connector object specification, but refer to our Secret object.

By now, Debezium should stream the changes from MySQL database into Kafka. To verify it, start watching mysql.inventory.customers Kafka topic:

oc run -n debezium-example -it --rm --image=quay.io/debezium/tooling:1.2  --restart=Never watcher -- kcat -b debezium-cluster-kafka-bootstrap:9092 -C -o beginning -t mysql.inventory.customers

Next, connect to MySQL database:

oc run -n debezium-example -it --rm --image=mysql:8.0 --restart=Never --env MYSQL_ROOT_PASSWORD=debezium mysqlterm -- mysql -hmysql -P3306 -uroot -pdebezium

and do some changes, e.g.:

> update customers set first_name="Sally Marie" where id=1001;

To clean up, just remove the project:

oc delete project debezium-example