LogstashJ : Java bindings for Logstash


I've just started working on a Java binding for Logstash.
My initial goal was to be able to write unit tests in Java but once we have a binding in place we could do so much more.

To give you some context, I'm working on a system where we handle more than 100 different types of events and we want to make sure that everything is working as expected. Currently we are running Rspec tests from a Maven build using Logstash distribution zip. This solution is working but it's not great.

With a Java binding, I could write a simple JUnit tests:

public void should_lowercase_message() throws IOException {
  URL url = Resources.getResource(LogstashFilterTest.class, "filter_config.conf");
  String config = Resources.toString(url, Charsets.UTF_8);
  Pipeline pipeline = Logstash.Pipeline.create(config);
  Event event = pipeline.send("You don't need to YELL!");
  assertThat(event.getMessage()).isEqualTo("you don't need to yell!");

My main concern is that I have to declare explicitly every dependencies to create the Logstash distribution (default patterns, filters, codecs...).
Also I don't know how I can provide a simple solution if a user want to unit test a custom filter or a use another version for a specific filter.

I'm aware that @colinsurprenant is already working on a project inside Logstash repository to create a Java API around event. As far as I know, the idea is to expose a pure Java API to plugins developers to support Java plugins.
We have different goal but maybe we should work together to avoid doing the same thing twice ?

What do you think ?

Hi @Mogztter - sorry for the delay, I am currently on vacation and will return on March 7th. I will followup with you on that week.


No worries, enjoy your vacation :smile:

Hi Mogztter,

Did you get any solution for this?

I am trying the same..


Not really but Logstash (core) is making good progress on the Java API: https://github.com/elastic/logstash/tree/master/logstash-core-event-java

I think the best approach here is to use the new Java API provided by Logstash to create a Java testing library for Logstash.

Thanks, I will check that.