How to use Narayana-lra server with GenericContainer?

[GregJohnStewart]

Hello! I hope this request is in the right place.

It would be great to have a TestContainer that spins up a narayana-lra server for testing LRA functionalities.

It appears that we would need to either create a barebones quarkus app to containerize to be the server, or use a standalone binary. Otherwise looks fairly straightforward:

https://jbossts.blogspot.com/2021/07/narayana-lra-update.html

https://narayana.io/downloads/index.html

Info on usage of Naraya:

https://jbossts.blogspot.com/2021/07/how-to-use-long-running-actions-between.html

https://quarkus.io/blog/using-lra/

[kiview]

Hey @GregJohnStewart, thanks for letting us know.

I'd assume this should be straightforward if there would be a Docker image for a narayana-lra server, then it might also work with our GenericContainer and there is no necessity for a dedicated container module.

What about this image?
https://hub.docker.com/r/jbosstm/lra-coordinator

This whole topic is outside of my expertise, so there is not much concrete I can advise on.

[GregJohnStewart]

That container looks good to me, unfortunately I am also quite new to LRA, so I can't speak much to it either (I'm looking for the test container so I can play with it!)

Outwardly it looks like a fairly simple service though

[kiview]

Given the sparse docs, you can try with the following GenericContainer (not tested):

new GenericContainer<>("jbosstm/lra-coordinator")
  .withExposedPort(8080)
  .waitingFor(Wait.forLogMessage(".*started in.*\\s", 1))

[GregJohnStewart]

Thanks! Seems to work well!

[kiview]

Cool, I will convert this into a GH Discussions Q&A (for hopefully better discoverability).

[bsofiato]

There is a caveat when it comes to Narayana calling back the participant.

During the LRA workflow, Narayana should call an endpoint on each participant to tell if they should commit the ongoing tx or rollback. This requires the container to access a socket on the host (i.e. the process running the tests).

To be able to do it, Narayana should call it using a special hostname -- http://host.testcontainers.internal (see) . Ports within this host must be made accessible by calling the Testcontainers.exposeHostPorts(%port%); (where %port% is the port on which the host will be listening to Narayana callbacks). The call should be done before the container starts.