# Assembling a Gatling (gun) ... how hard can it be?

### 2018-03-07 Software Engineering Scala

Back to the roots!!!

I am writing Gatling tests (again :)). (Obviously) I used to do this (a lot :)), when I was with Gilt (for an obvious reason :)).

To get going again, I had to make the basics work … again.

The basics are: Make the sbt-gatling plugin work to build (end-to-end integration) tests/simulations and then create a “deployable” (fat) jar (using sbt-assembly).

This proved to be more difficult than I thought (because this used to work).

Everytime I was starting the jar with java -jar load-test.jar -s computerdatabase.BasicItSimulation I got the (in)famous There is no simulation script. Please check that your scripts are in user-files/simulations error message.

After some heavy debugging, I realized that the settings in gatling.conf override the command-line parameters (and in my case I had copied the gatling-default.conf into the resource directory and in that file simulationClass is set to "").

Fixed it. Working now. Something to be aware off.