Kafka's Docker

Yet another Kafka's Docker repository

Introduction

This is heavily based on wurstmeister/kafka-docker implementation but with opinionated changes that matter to me.

• Based on the official Java alpine image.
• Use --no-cache option when adding packages.
• Install minimal packages.
• Avoid external executable scripts in Dockerfile whenever possible.
• Use entrypoint:
  • Ensure that kafka-server-start.sh are running as PID 1.
  • When running the container with custom commands, it ensure that all the environment variables and configurations are setup accordingly.

This also means that I have removed several features:

• No custom init script
• No create topics
• No discovering broker list

Some of these features may be added in the future but the goal of this project is to build a production ready Kafka docker image.

Auto Assigned Broker ID

If you did not provides a KAFKA_BROKER_ID environment variable, The system will use nextbrokerid to figure out the next broker ID to use. Warning, if you use auto assigned broker ID, scaling them concurrently is likely to cause race condition. It is recommended that you add an interval in between scaling.

Environment Variables

Name	Description	Default Value
SCALA_VERSION	The Scala version	2.12
KAFKA_VERSION	The Kafka version	0.10.2.1
KAFKA_HOME	The home directory of Kafka	/opt/kafka
KAFKA_PORT	The port to run Kafka on	9092
KAFKA_BROKER_ID	The id of the broker. This must be set to a unique integer for each broker.
KAFKA_LOG_DIRS	A comma seperated list of directories under which to store log files	/kafka/kafka-logs-$HOSTNAME
KAFKA_ZOOKEEPER_CONNECT	Zookeeper connection string (see zookeeper docs for details).
KAFKA_*	Any environment variables that begin with KAFKA_ (except for KAFKA_VERSION and KAFKA_HOME) will be written to /opt/kafka/config/server.properties accordingly. e.g. KAFKA_ZOOKEEPER_CONNECT=localhost:2181 ⤑ zookeeper.connect=localhost:2181

Usage

Build

docker build --tag=lxcid/kafka .

Push

docker push $DOCKER_ID_USER/kafka