kroxylicious-sample

Kroxylicious Sample

This sample filter project provides examples to help you learn how custom filters work in Kroxylicious. To learn more about Kroxylicious, visit the docs.

Getting started

Build

Building the sample project is easy! You can build the kroxylicious-sample jar either on its own or with the rest of the Kroxylicious project.

To build all of Kroxylicious, including the sample:

mvn verify

To build the sample on its own:

mvn verify -pl :kroxylicious-sample --also-make

Note: If you build just the kroxylicious-sample module, you will need to also build the kroxylicious-app module separately (with dist profile, as shown below) in order to run the sample.

Build with the dist profile for creating executable JARs:

mvn verify -Pdist -Dquick

Note: You can leave out --also-make from these commands if you have already built the whole Kroxylicious project.

Run

Build both kroxylicious-sample and kroxylicious-app with the dist profile as above, then run the following command:

KROXYLICIOUS_CLASSPATH="kroxylicious-sample/target/*" kroxylicious-app/target/kroxylicious-app-*-bin/kroxylicious-app-*/bin/kroxylicious-start.sh --config kroxylicious-sample/sample-proxy-config.yaml

Configure

Filters can be added and removed by altering the filters list in the sample-proxy-config.yaml file. You can also reconfigure the sample filters by changing the configuration values in this file.

The SampleFetchResponseFilter and SampleProduceRequestFilter each have two configuration values that must be specified for them to work:

• findValue - the string the filter will search for in the produce/fetch data
• replacementValue - the string the filter will replace the value above with

Default Configuration

The default configuration for SampleProduceRequestFilter is:

filtersDefinitions:
  - name: my-produce-replacer
    type: SampleProduceRequest
    config:
      findValue: foo
      replacementValue: bar

This means that it will search for the string foo in the produce data and replace all occurrences with the string bar. For example, if a Kafka Producer sent a produce request with data {"myValue":"foo"}, the filter would transform this into {"myValue":"bar"} and Kroxylicious would send that to the Kafka Broker instead.

The default configuration for SampleFetchResponseFilter is:

filterDefinitions:
  - name: my-fetch-replacer
    type: SampleFetchResponse
    config:
      findValue: bar
      replacementValue: baz

This means that it will search for the string bar in the fetch data and replace all occurrences with the string baz. For example, if a Kafka Broker sent a fetch response with data {"myValue":"bar"}, the filter would transform this into {"myValue":"baz"} and Kroxylicious would send that to the Kafka Consumer instead.