Chapter 2. Starting the services
Using Debezium requires AMQ Streams and the Debezium connector service. To start the services needed for this tutorial, you must:
2.1. Setting up a Kafka cluster
You use AMQ Streams to set up a Kafka cluster. This procedure deploys a single-node Kafka cluster.
In your OpenShift 4.x cluster, create a new project:
$ oc new-project debezium-tutorial
- Change to the directory where you downloaded the AMQ Streams 2021.q3 OpenShift installation and example files.
Deploy the AMQ Streams Cluster Operator.
The Cluster Operator is responsible for deploying and managing Kafka clusters within an OpenShift cluster. This command deploys the Cluster Operator to watch just the project that you created:
$ sed -i 's/namespace: .*/namespace: debezium-tutorial/' install/cluster-operator/*RoleBinding*.yaml $ oc apply -f install/cluster-operator -n debezium-tutorial
Verify that the Cluster Operator is running.
This command shows that the Cluster Operator is running, and that all of the Pods are ready:
$ oc get pods NAME READY STATUS RESTARTS AGE strimzi-cluster-operator-5c6d68c54-l4gdz 1/1 Running 0 46s
Deploy the Kafka cluster.
This command uses the
kafka-ephemeral-single.yamlCustom Resource to create an ephemeral Kafka cluster with three ZooKeeper nodes and one Kafka node:
$ oc apply -f examples/kafka/kafka-ephemeral-single.yaml
Verify that the Kafka cluster is running.
This command shows that the Kafka cluster is running, and that all of the Pods are ready:
$ oc get pods NAME READY STATUS RESTARTS AGE my-cluster-entity-operator-5b5d4f7c58-8gnq5 3/3 Running 0 41s my-cluster-kafka-0 2/2 Running 0 70s my-cluster-zookeeper-0 2/2 Running 0 107s my-cluster-zookeeper-1 2/2 Running 0 107s my-cluster-zookeeper-2 2/2 Running 0 107s strimzi-cluster-operator-5c6d68c54-l4gdz 1/1 Running 0 8m53s
2.2. Deploying Kafka Connect
After setting up a Kafka cluster, you deploy Kafka Connect in a custom container image for Debezium. This service provides a framework for managing the Debezium MySQL connector.
- Podman or Docker is installed and you have sufficient rights to create and manage containers.
- Download the Debezium MySQL Connector 1.5 archive from the Red Hat Integration download site.
Extract the Debezium MySQL connector archive to create a directory structure for the connector plug-in, for example:
tree ./my-plugins/ ./my-plugins/ ├── debezium-connector-mysql │ ├── ...
Create and publish a custom image that runs Kafka Connect with the Debezium MySQL connector:
Create a new
registry.redhat.io/amq7/amq-streams-kafka-28-rhel8:1.8.0as the base image. In the following example, you would replace
my-pluginswith the name of your plug-ins directory:
FROM registry.redhat.io/amq7/amq-streams-kafka-28-rhel8:1.8.0 USER root:root COPY ./my-plugins/ /opt/kafka/plugins/ USER 1001
Before Kafka Connect starts running the connector, Kafka Connect loads any third-party plug-ins that are in the
Build the container image. For example, if you saved the
Dockerfilethat you created in the previous step as
debezium-container-for-mysql, and if the
Dockerfileis in the current directory, enter one of the following command:
podman build -t debezium-container-for-mysql:latest .
docker build -t debezium-container-for-mysql:latest .
Push your custom image to your container registry. Enter one of the following commands:
podman push <my_registry.io>/debezium-container-for-mysql:latest
docker push <my_registry.io>/debezium-container-for-mysql:latest
Point to the new container image by editing the
spec.imageproperty of the
KafkaConnectcustom resource. If this property is set, its value overrides the
STRIMZI_DEFAULT_KAFKA_CONNECT_IMAGEvariable in the Cluster Operator. For example:
apiVersion: kafka.strimzi.io/v1beta2 kind: KafkaConnect metadata: name: my-connect-cluster annotations:strimzi.io/use-connector-resources: "true" spec: #... image: debezium-container-for-mysql
Kafka Connect is now running. The container has a Debezium MySQL connector but this connector is not yet configured to capture changes in a database.
2.3. Deploying a MySQL database
At this point, you have deployed a Kafka cluster and the Kafka Connect service with the Debezium MySQL database connector. However, you still need a database server from which Debezium can capture changes. In this procedure, you start a MySQL server with an example database.
Start a MySQL database by running the following command, which starts a MySQL database server configured with an example
$ oc new-app --name=mysql quay.io/debezium/example-mysql:latest
Configure credentials for the MySQL database by running the following command, which updates the deployment configuration for the MySQL database to add the user name and password:
$ oc set env dc/mysql MYSQL_ROOT_PASSWORD=debezium MYSQL_USER=mysqluser MYSQL_PASSWORD=mysqlpw
Verify that the MySQL database is running by invoking the following command, which is followed by the output that shows that the MySQL database is running, and that the pod is ready:
$ oc get pods -l app=mysql NAME READY STATUS RESTARTS AGE mysql-1-2gzx5 1/1 Running 1 23s
Open a new terminal and log into the sample
This command opens a MySQL command line client in the pod that is running the MySQL database. The client uses the user name and password that you previously configured:
$ oc exec mysql-1-2gzx5 -it -- mysql -u mysqluser -pmysqlpw inventory mysql: [Warning] Using a password on the command line interface can be insecure. Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 7 Server version: 5.7.29-log MySQL Community Server (GPL) Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
List the tables in the
mysql> show tables; +---------------------+ | Tables_in_inventory | +---------------------+ | addresses | | customers | | geom | | orders | | products | | products_on_hand | +---------------------+ 6 rows in set (0.00 sec)
Explore the database and view the data that it contains, for example, view the
mysql> select * from customers; +------+------------+-----------+-----------------------+ | id | first_name | last_name | email | +------+------------+-----------+-----------------------+ | 1001 | Sally | Thomas | firstname.lastname@example.org | | 1002 | George | Bailey | email@example.com | | 1003 | Edward | Walker | firstname.lastname@example.org | | 1004 | Anne | Kretchmar | email@example.com | +------+------------+-----------+-----------------------+ 4 rows in set (0.00 sec)