A small Quarkus + Kafka playground that lets you run a local Kafka stack via Podman and push messages through a simple pipeline.

This repo ships a local stack defined in docker-compose.yml:

• Kafka (KRaft mode, no ZooKeeper)
• Kafka Connect (REST API on :8083)
• Kafbat UI (web UI on :8080)
• Apicurio Registry (HTTP API/UI on :8082, backed by Postgres)
• Postgres (for Apicurio storage, on :5432)
• A one-shot init container that creates the demo topics

podman-compose up -d

podman-compose down

• Kafka (internal / containers): kafka:9092
• Kafka (from your laptop/tools): localhost:29092
• Quarkus Backend REST: http://localhost:9090
• Kafka Connect REST: http://localhost:8083
• Kafbat UI: http://localhost:8080
• Apicurio Registry:
  • UI/API base: http://localhost:8082
  • v3 API base: http://localhost:8082/apis/registry/v3
  • Confluent-compatible API (used by Kafbat UI): http://localhost:8082/apis/ccompat/v7
• Postgres (optional access): localhost:5432 (db/user/pass: registry)

The compose stack auto-creates these topics on startup:

• example-input-v1
• example-output-v1

The app demonstrates a minimal end-to-end flow:

1. The REST endpoint publishes to the input topic.
2. InputConsumer consumes, transforms the payload, then publishes to the output topic.
3. (Optional) You can observe output via Kafka tooling / UI.

Dev mode:

./mvnw quarkus:dev

Call the endpoint with a value query param.

• It will generate a random UUID as Kafka record key
• It will publish the query param string as the record value

curl "http://localhost:8080/publish?value=hello"

Expected response:

{"key":"<uuid>","value":"hello"}

./mvnw package
java -jar target/quarkus-app/quarkus-run.jar

• Apache Kafka Client
• Messaging - Kafka Connector