How to dynamically set a port (from a Testcontainers container)

Gatling (Open-Source)
4

Your call.

Regarding coding what you’re trying to do, it’s pretty straightforward.
Just don’t use the before hook and directly place all the code you need in the instance initializer.

{
  myTestcontainers.setup();
  // capture application port from getMappedPort by some mechanism, e.g. return it from that call and assign to a variable in the simulation class
  int myPort = ???;

 HttpProtocolBuilder httpProtocol = http
        .baseUrl("http://localhost:" + myPort)
        .acceptHeader("application/json")
        .userAgentHeader("Gatling");

  ScenarioBuilder getFoo = scenario("get foo")
            .exec(http("Get Foo")
                    .get("/foo")
                    .check(status().is(200)))
            .pause(Duration.ofMillis(500));
 
 setUp(getFoo.injectOpen(constantUsersPerSec(10).during(300)).protocols(httpProtocol));
}