feat: simulations format

[kkulak]

Description

Gatling scenarios can be defined in two ways at the moment:

• via hardcoded simulationData
• or via custom docker image. However, the only accepted format is Gatling Bundle, which has its own limitations. For example, we cannot define simulation in languages other than Scala, while Gatling supports Kotlin and Java ootb.

Furthermore, I'd like to make use of build tool, sth like that:

• https://gatling.io/blog/migrate-to-the-gradle-build-tool
• https://github.com/gatling/gatling-gradle-plugin-demo-kotlin

My proposal is to add a new property - simulationsFormat - which modifies the command being run by gatling-runner - it only decides whether we should use gatling.sh or gradle wrapper for the test execution. I've already checked the changed on my private EKS cluster, and they seem to work correctly, including features like S3 results upload.

Tomorrow I'll add some examples and update docs. Let me know please @kane8n @gold-kou what are your thoughts. Cheers!

Checklist

Please check if applicable

• Tests have been added (if applicable, ie. when operator codes are added or modified)
• Relevant docs have been added or modified (if applicable, ie. when new features are added or current features are modified)

[kane8n]

Thanks for the great proposal!
I left some review comments, please check them out.

[kane8n]

Is there a reason why you don't pass the simulations or resources directories as arguments?

[kkulak]

with Gatling Gradle Plugin, these files do have quite typical locations:

• simulations are under src/gatling/java or src/gatling/kotlin or src/gatling/java
• resources are under src/gatling/resources

I see that there's an option to customize these options via:

sourceSets {
  gatling {
    scala.srcDir "folder1" <1>
    // or
    scala.srcDirs = ["folder1"] <2>

    resources.srcDir "folder2" <3>
    // or
    resources.srcDirs = ["folder2"] <4>
  }
}

but I do not know upfront in which language the simulations were written, so it's quite hard to guess. IMHO convention over configuration rule applies here perfectly :)

[kkulak]

@kane8n docs updated, comms addressed. Let me know please if there's anything pending :)

[kane8n]

@kkulak
Thank you!
I think the updated one looks good.
I'll ask other members to review it, but please you'll have to wait until next week.

[kkulak]

hi All, did you have a chance to look into the PR? @gold-kou @kane8n

[kane8n]

@kkulak
It takes a little time because other members are busy. Sorry for keeping you waiting.

[gold-kou]

@kkulak CC: @kane8n
Sorry for being late.
To be honest, I'm not familiar with using bundle or gradle as a simulation.
However looks no regression at least.

Thx for your contribution. 🎉

[kane8n]

lgtm!
We'll have it ready for release this week.

[kane8n]

@kkulak
Thanks for the contribute, we released it as v0.9.7!