@northscaler/kafka-test-support

kafka-test-support

Handy-dandy Kafka integration testing utility that starts a local Docker compose environment running Kafka & Zookeeper, if you're not running in a CI/CD pipeline. This allows you to run integration tests locally in a manner similar to how they'd be run in the CI/CD pipeline. This module does nothing when running in a CI build pipeline, because Kafka & Zookeeper should be configured as part of the build via something like .gitlab-ci.yml's services element.

This package is intended to be installed in your project in devDependencies.

Your application must install its desired version of its desired Kafka Node.js client; this library simply launches Kafka with Zookeeper and provides a broker list.

NOTE: requires a Unix-y shell (/usr/bin/env sh) to be available. This is not designed to run on Windows; PRs/MRs welcome.

Usage:

const kafkaConnect = require('kafka-test-support')

// returns kafka information, including brokers
const kafkaInfo = await kafkaConnect()

// Kafka is now running; use kafkaInfo.brokers to connect your kafka client

Configuration

The default configuration is pretty conventional, with the sole exception of the default port that Kafka will listen on for clients. Instead of 9092, which might already be in use on developers' machines when they run integration tests, the default configuration uses 29092. TODOs include using alternative ports of the user's choosing & searching for an available port.

NOTE: This module detects when it's running in a CI/CD pipeline by seeing if the environment variable CI is of nonzero length.

Environment variables

The following environment variables can be set to configure it:

• KAFKA_TEST_SUPPORT_KAFKA_TAG: The tag of the kafka Docker image or custom image to use, default "latest"
• KAFKA_TEST_SUPPORT_ZOOKEEPER_TAG: The tag of the kafka Docker image or custom image to use, default "latest"