Running Dockerised Kafka Connect worker on GCP
I talk and write about Kafka and Confluent Platform a lot, and more and more of the demos that I’m building are around Confluent Cloud. This means that I don’t have to run or manage my own Kafka brokers, Zookeeper, Schema Registry, KSQL servers, etc which makes things a ton easier. Whilst there are managed connectors on Confluent Cloud (S3 etc), I need to run my own Kafka Connect worker for those connectors not yet provided. An example is the MQTT source connector that I use in this demo. Up until now I’d either run this worker locally, or manually build a cloud VM. Locally is fine, as it’s all Docker, easily spun up in a single docker-compose up -d command. I wanted something that would keep running whilst my laptop was off, but that was as close to my local build as possible—enter GCP and its functionality to run a container on a VM automagically.
You can see the full script here. The rest of this article just walks through the how and why.
Using Kafka Connect and Debezium with Confluent Cloud
This is based on using Confluent Cloud to provide your managed Kafka and Schema Registry. All that you run yourself is the Kafka Connect worker.
Optionally, you can use this Docker Compose to run the worker and a sample MySQL database.
Copying data between Kafka clusters with Kafkacat
kafkacat gives you Kafka super powers 😎
I’ve written before about kafkacat and what a great tool it is for doing lots of useful things as a developer with Kafka. I used it too in a recent demo that I built in which data needed manipulating in a way that I couldn’t easily elsewhere. Today I want share a very simple but powerful use for kafkacat as both a consumer and producer: copying data from one Kafka cluster to another. In this instance it’s getting data from Confluent Cloud down to a local cluster.
Connecting KSQL to a Secured Schema Registry
Confluent Cloud now includes a secured Schema Registry, which you can use from external applications, including KSQL.
To configure KSQL for it you need to set:
ksql.schema.registry.url=https://<Schema Registry endpoint>
ksql.schema.registry.basic.auth.credentials.source=USER_INFO
ksql.schema.registry.basic.auth.user.info=<Schema Registry API Key>:<Schema Registry API Secret>