Config parameters

Hi All,

I have passed environment variables in my simulation.
I have succeeded in passing them using

Through shell file:
: ${Users:=1}
export Users=$Users
: ${Ramp:=1}
export Ramp=$Ramp

And accessing them in config file:

var totalUsers:Int = if (System.getenv(“Users”) != null) System.getenv(“Users”).toInt else 1
var rampOverSeconds:Int = if (System.getenv(“Ramp”) != null) System.getenv(“Ramp”).toInt else 1

Now I want to pass scenario names using config parameters.
val foo = exec(bar.foobar_function)

Can anyone help me understanding, how to pass and access config parameters for above scenario.


Scenario names are not passed through the environment. For that, you need a command line parameter if you are using or gatling.bat. See

If you are using maven or sbt, someone else will have to tell you how to do that. :slight_smile:

If you are using maven or sbt, someone else will have to tell you how to do that

I’d be interested to know if we can pass parameters through sbt. I was thinking, it’d just be:

$ SBT_OPTS="-Dfoo=bar" sbt

// Script
println("value: " + System.getProperty(“foo”))

But I am getting null.

Many Thanks


Even if Gatling SBT Plugin provides System properties propagation to Gatling itself, this won’t work as-is if you override javaOptions (which you do in your load tests published on Github).

To re-enable system properties propagation to Gatling :

import io.gatling.sbt.PropertyUtils._

javaOptions in Gatling := /* your javaOptions */ ++ propagatedSystemProperties



Hi Pierre

import io.gatling.sbt.PropertyUtils._

I am receiving the error:
error: object PropertyUtils is not a member of package io.gatling.sbt


import io.gatling.sbt.utils.PropertyUtils._

Hi Pierre,

Thanks for getting back.

Here is my set up:

// build.sbt

import io.gatling.sbt.utils.PropertyUtils._

javaOptions in Gatling := Seq("-Xms2G", “-Xmx5G”) ++ propagatedSystemProperties

// Gatling Script
println("value: " + System.getProperty(“foo”))

// JAVA_OPTS passed to sbt
JAVA_OPTS="-Dfoo=bar" sbt

However, when I run the test, I still the value as null.

Many Thanks


Are you sure that JAVA_OPTS is used by SBT ?
For example, if you’re using Paul Philips’s script from sbt-extras, the env variable is JVM_OPTS, not JAVA_OPTS.

To be sure, try using your system property inside your build.sbt.
For example, add name := sys.props("foo”) to your build. And then run show name inside SBT.
If you get a null, this means that SBT itself doesn’t have access to your system property and so there’s not a single chance it can propagate it to Gatling.
Double check SBT help (sbt -h) to get sure that you’re using the correct environment variable to pass your system properties.



Hi Pierre,

Thanks for the pointers. SBT_OPTS seem to work:

$ SBT_OPTS="-Denv=test" sbt

// script
val env = System.getProperty(“env”)

Many Thanks


Hi All,

Sorry for breaking in the discussion.

I am not using sbt or maven.

I have configured a shell file which passes config parameters through environment variables, and I am successful passing them as per mentioned in first post.

Now I want to pass scenario names through environment variables, which i am not able to pass using string parameters.
Can you help me with any way which can be used for passing scenario names.


I am trying to pass parameters from shell file.

: ${SingleFilter:=“Foo.getBarScenario”}

And fetch them in my simulation file.

val config_filter:String = if (System.getenv(“SingleFilter”) != null) System.getenv(“SingleFilter”) else “Foo1.getBar1”
// if I print value of config_filter here, it displays Foo.getBarScenario

val singleFiltrScns = exec(s"config_filter")

val fooUIScenario = scenario(“Foo UI Simulation”)

//but when I execute simulation gatling gives me following error

// 17:04:16.567 [ERROR] i.g.c.a.b.SessionHookBuilder$$anonfun$build$1$$anon$1 - ‘sessionHook-1’ failed to execute

You can’t set the scenario name via an environment variable. You use a command line parameter. Read the docs on startup parameters, and then build an appropriate shell script wrapper.