Proxy quick start

This quick start will guide you through deploying the proxy.

Kroxylicious is a Java application based on Netty, which means it will run anywhere you can run a JVM.

Getting started

Prerequisites

Java

To get started deploying Kroxylicious, you will need to install a Java Runtime Environment (JRE) with minimum version 17. This does not come included with Kroxylicious.

Some operating systems come with a JRE already installed. You can check what Java version you have installed by running the following command:

java -version

If you get an error or the command doesn’t return anything, you may not have a JRE installed, or your JRE may not have been correctly added to your system’s PATH variable.

Apache Kafka®

You will also need a running Apache Kafka® cluster for Kroxylicious to proxy. The official Apache Kafka® quick start has instructions for setting up a local bare metal cluster.

Once your cluster is set up, the cluster bootstrap address used by Kroxylicious can be changed in the configuration YAML file (see the Configure section below).

Step 1: Download and install the proxy

Kroxylicious can be downloaded from the releases page of the Kroxylicious GitHub repository, or from Maven Central.

Download kroxylicious-app-0.4.1-bin.zip from the GitHub release page. Optionally, verify the contents of the package with the attached kroxylicious-app-0.4.1-bin.zip.asc file.

If you’re trying Kroxylicious out on Linux or macOS, you may find the .tar.gz format easier to work with. We’re using the .zip files in this quick start for cross-platform compatibility, but we recommend you use whichever format you’re most familiar with.

Extract the downloaded Kroxylicious Zip file into the directory you would like to install Kroxylicious in. Ensure the kroxylicious-start.sh and run-java.sh files in the bin/ directory within the extracted folder have at least read and execute (r-x) permissions for the owner.

Step 2: Configure the proxy

Kroxylicious is configured with YAML. From the configuration file you can specify how Kroxylicious presents each Apache Kafka® broker to clients, where Kroxylicious will locate the Apache Kafka® cluster(s) to be proxied, and which filters Kroxylicious should use along with any configuration for those filters.

An example configuration file can be found in the config/ directory of the extracted Kroxylicious folder, which you can either modify or use as reference for creating your own configuration file.

For this quickstart we will use Kroxylicious in Port-Per-Broker configuration, and assume that both your Apache Kafka® cluster and clients are running on your local machine and using their default configuration. This means we can use the example proxy config file that comes with Kroxylicious.

If your machine uses a non-standard port configuration, or if you have used custom settings for your Apache Kafka® cluster (or if your cluster is running on a different machine) you will need to adjust your Kroxylicious configuration accordingly. More information about configuring Kroxylicious can be found in the documentation.

Step 3: Start the proxy

From within the extracted Kroxylicious folder, run the following command:

./bin/kroxylicious-start.sh --config config/example-proxy-config.yml

To use your own configuration file instead of the example, just replace the file path after --config.

Step 4: Configure Kafka clients to use it

Your client(s) will need to point to the proxy (using the configured address) rather than directly at the Apache Kafka® cluster.

In each command below, substitute $KROXYLICIOUS_BOOTSTRAP for the bootstrap address of your proxy instance.

i. Create a topic via the proxy

Create a topic called “my_topic” using the kafka-topics.sh command line client:

bin/kafka-topics.sh --create --topic my_topic --bootstrap-server $KROXYLICIOUS_BOOTSTRAP

ii. Produce a string to your topic via the proxy

Produce the string “hello world” to your new topic using the kafka-console-producer.sh command line client:

echo "hello world" | bin/kafka-console-producer.sh --topic my_topic --bootstrap-server $KROXYLICIOUS_BOOTSTRAP

iii. Consume your string from your topic via the proxy

Consume your string (“hello world”) from your topic (“my_topic”) using the kafka-console-consumer.sh command line client:

bin/kafka-console-consumer.sh --topic my_topic --from-beginning --bootstrap-server $KROXYLICIOUS_BOOTSTRAP

In each command below, substitute $KROXYLICIOUS_BOOTSTRAP for the bootstrap address of your proxy instance.

i. Create a topic with Kaf via the proxy

Create a topic called “my_topic” using Kaf:

kaf -b $KROXYLICIOUS_BOOTSTRAP topic create my_topic

ii. Produce a string to your topic with Kaf via the proxy

Produce the string “hello world” to your new topic:

echo "hello world" | kaf -b $KROXYLICIOUS_BOOTSTRAP produce my_topic

iii. Consume your string from your topic with Kaf via the proxy

Consume your string (“hello world”) from your topic (“my_topic”):

kaf -b $KROXYLICIOUS_BOOTSTRAP consume my_topic