Kafka Configurator

Command line tool to create and update Kafka topics based on the provided configuration.

This software can be used in one of two ways:

• As a standalone tool for automatically creating topics and updating their parameters. It reads a YAML description of the desired setup, compares it with the current state and alters the topics that are different.

• As a dependency that can be added to your code-base as a library that allows you to manage kafka-topics within your application.

Usage as a standalone program

Download

Binary archive

Released artifacts are published to Bintray as zip or tgz archives.

It does not require an installation process: just extract the archive into any directory and execute bin/kafka-configurator (or bin\kafka-configurator.bat on Windows) to see the usage instructions.

Docker Image

The Docker Image is available from Docker Hub at skyuk/kafka-configurator

Usage: kafka-configurator [options]

  -f, --files <file1>,<file2>...
                           Topic configuration files
  --bootstrap-servers <value>
                           Kafka brokers URLs for bootstrap (comma-separated)
  --properties <value>     Kafka admin client config as comma-separated pairs

The topic configuration file has the following format:

topic1:
  partitions: 10
  replication: 3
  config:
    cleanup.policy: compact
    delete.retention.ms: 86400000
    min.compaction.lag.ms: 21600000
    retention.ms: 0
    min.insync.replicas: 3

topic2:
  partitions: 5
  replication: 2
  config:
    cleanup.policy: delete
    delete.retention.ms: 0
    retention.ms: 604800000
    min.insync.replicas: 2

The root items are topic names to be created or updated, and contain their configuration parameters: partitions and replication are integers, while the config block accepts any valid topic-level configuration. We let Kafka validate these configurations for us so we don't have to explicitly support each topic-level configuration. Yaml anchors can also be used to reduce duplication in the topic configuration (see example here).

Demo

Create a test-topics.yml file with the contents of the example configuration above.

Using the extracted binary

Start Kafka and Zookeeper using two separate shells in the Kafka root directory:

1$ bin/zookeeper-server-start.sh config/zookeeper.properties
2$ bin/kafka-server-start.sh config/server.properties

Execute the Kafka Configurator:

$ bin/kafka-configurator -f test-topics.yml --zookeeper localhost:2181

Query the topics using the CLI tool bundled with Kafka:

$ bin/kafka-topics.sh --zookeeper localhost:2181 --describe
Topic:topic1    PartitionCount:10       ReplicationFactor:1     Configs:retention.ms=0,delete.retention.ms=86400000,min.insync.replicas=2,cleanup.policy=compact
        ...
Topic:topic2    PartitionCount:5        ReplicationFactor:1     Configs:retention.ms=86400000,delete.retention.ms=0,min.insync.replicas=2,cleanup.policy=delete
        ...

Any changes to the test-topics.yml file will be applied to the existing topics at each subsequent run.

Using the Docker image

Assuming you know the <zookeeper_address> and have placed your config file named test-topics.yml inside the <config_dir_on_host> directory on the Docker host, an example of how to run the image is:

docker run -it -v <config_dir_on_host>:/etc/kafka-configurator skyuk/kafka-configurator -f=/etc/kafka-configurator/test-topics.yml --zookeeper=<zookeeper_address>

Alternatively you could extend the skyuk/kafka-configurator image and COPY your configuration file directly into your extended image.

Injecting Kafka Admin client config

Any Kafka Admin client config is supported, both when running the binary directly or via Docker.

These can be passed in the --properties command line option as key=value comma separated pairs:

kafka-configurator -f test-topics.yml --zookeeper localhost:2181 --properties client.id=foo,ssl.key.password=bar

Or they can be injected as environment variables prefixed with KAFKA_:

docker run -it -v <config_dir_on_host>:/etc/kafka-configurator -e KAFKA_CLIENT_ID=foo -e KAFKA_SSL_KEY_PASSWORD=bar skyuk/kafka-configurator -f=/etc/kafka-configurator/test-topics.yml --zookeeper=<zookeeper_address>

Usage for adding as a dependency

SBT

useJCenter := true

libraryDependencies += "com.sky" %% "kafka-configurator" % "VERSION"

Gradle

repositories {
    jcenter()
}

compile 'com.sky:kafka-configurator_2.12:VERSION'

Maven

<repositories>
    <repository>
        <id>jcenter</id>
        <name>jcenter</name>
        <url>http://jcenter.bintray.com</url>
    </repository>
</repositories>

<dependency>
  <groupId>com.sky</groupId>
  <artifactId>kafka-configurator_2.12</artifactId>
  <version>VERSION</version>
</dependency>

Scala Example:

val config = AppConfig(files = Seq(new File("topics.yml")), bootstrapServers = "examplekafka.com:9092")
val result = KafkaConfiguratorApp.reader(config).configureTopicsFrom(config.files.toList)

result match {
  case Success((Nil, logs)) => logger.info(s"Topics successfully configured. $logs")
  case Success((errors, logs)) => logger.error(s"Configurator errors: $errors, $logs")
  case Failure(e) => logger.error("Kafka Configurator has failed", e)
}