How to run Quarkus programatically in Test mode

I am trying to run acceptance tests with concordion fixtures in a quarkus project. Concordion does not work with Junit5 so I am using its original @Run(ConcordionRunner.class).

I am creating a superclass to start my quarkus application before tests like that:

@RunWith(ConcordionRunner.class)
public abstract class AbstractFixture {
        public static RunningQuarkusApplication application;
        protected static RequestSpecification server;
        
        protected AbstractFixture() {
            setUp();
        }

        public void setUp() {
            if(application == null) {               
                startApplication();
                server = new RequestSpecBuilder()                                       
                                        .setPort(8081)
                                        .setContentType(ContentType.JSON)
                                        .build();
            }
        }

        
        private void startApplication() {
            try {
                PathsCollection.Builder rootBuilder = PathsCollection.builder();

                Path testClassLocation = PathTestHelper.getTestClassesLocation(getClass());

                rootBuilder.add(testClassLocation);

                final Path appClassLocation = PathTestHelper.getAppClassLocationForTestLocation(
                        testClassLocation.toString());
                rootBuilder.add(appClassLocation);

                application = QuarkusBootstrap.builder()
                                    .setIsolateDeployment(false)
                                    .setMode(QuarkusBootstrap.Mode.TEST)                        
                                    .setProjectRoot(Paths.get("").normalize().toAbsolutePath())
                                    .setApplicationRoot(rootBuilder.build())    
                                    .build()
                                    .bootstrap()
                                    .createAugmentor()
                                    .createInitialRuntimeApplication()
                                    .run();
                
            } catch (BindException e) {             
                e.printStackTrace();
                System.out.println("Address already in use - which is fine!");
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }   
            
}

The code above is working but I can't change the default port 8081 to any other.

If I print the config property in my Test class like below, it prints the port correctly, but quarkus is not running on it:

public class HelloFixture extends AbstractFixture {

    public String getGreeting() {
        Response response = given(server).when().get("/hello");
        System.out.println("Config[port]: " + application.getConfigValue("quarkus.http.port", String.class));
        
        return response.asString();
    }
}

How can I specify the configuration file or property programatically before run?

I found the answer. At first, I was referencing the wrong property "quarkus.http.port" instead of "quarkus.http.test-port".

Despite that, I found the way to override properties before run:

...

StartupAction action = QuarkusBootstrap.builder()
                                    .setIsolateDeployment(false)
                                    .setMode(QuarkusBootstrap.Mode.TEST)                        
                                    .setProjectRoot(Paths.get("").normalize().toAbsolutePath())
                                    .setApplicationRoot(rootBuilder.build())    
                                    .build()
                                    .bootstrap()
                                    .createAugmentor()
                                    .createInitialRuntimeApplication();
                
action.overrideConfig(getConfigOverride());
                
application = action.run();
...

private Map<String, String> getConfigOverride() {
    Map<String, String> config = new HashMap<>();
    config.put("quarkus.http.test-port", "18082");
    return config;
}