Another example of Gatling scenario with complex authentication/response processing and number of simple requests that have been used as a test.

LoginSimulation.scala

package mobilepackage

import io.gatling.core.Predef._
import io.gatling.core.session._
import io.gatling.http.Predef._
import scala.concurrent.duration._
import scala.util.parsing.json._
import general._

class LoginSimulation extends Simulation {
    // configure proxy
    var httpProxy = Proxy(DomainProxy.host, DomainProxy.port)

    // set headers
    val sentHeaders = Map(
        "User-Agent" -> "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:35.0) Gecko/20100101 Firefox/35.0",
        "Accept" -> "application/json, text/javascript, */*; q=0.01",
        "Accept-Language" -> "en-US,en;q=0.5",
        "DNT" -> "1",
        "Connection" -> "keep-alive",
        "Pragma" -> "no-cache",
        "Cache-Control" -> "no-cache",
        "Referer" -> "http://localhost/mobile/controlpanel/"
    )

    // configure basic http
    val httpConf = http
        .proxy(httpProxy)
        .baseURL("http://localhost")
        .headers(sentHeaders)

    object Actions {
        // fetch token key and number of iterations and store them back in session
        def retrieveAuthData(session: Session, datakey: String) : AuthData = {
            // get response as a string
            var t:String = session.get(datakey).as[String];
            // weird bug of the framework on a server that generates json with some strange symbol in the beginning
            // remove everything from the beginning of the string to reach first symbol "{"
            var altered:String = t.slice(t.indexOfSlice("{"), t.length);
            var a:Map[String, Any] = Util.mapFromJsonString(altered);
            // retrieve parameters from json
            var token:String = a("Token").asInstanceOf[String];
            var iterations:Int = a("KeyStrengtheningIterations").asInstanceOf[Double].toInt;
            var mobileEncryption:Boolean = a("MobileEncryption").asInstanceOf[Boolean];

            return new AuthData(token, iterations, mobileEncryption);
        }

        // action to prepare data to create a user
        def prepare(usertoken: UserToken, authdata: AuthData) : String = {
            var a:String = Util.randomName(10);
            var b:String = Util.randomName(10);
            var json:String = Util.jsonFromMap(Map(
                "DocumentType" -> "UserCreateData",
                "Username" -> a,
                "FirstName" -> a,
                "LastName" -> a,
                "CompanyName" -> "Cookies",
                "Password" -> b,
                "Image" -> Util.defaultImageBinaryData(),
                "Email" -> "cookiessupport@cookies.com",
                "Active" -> "true"
            ));
            return MobileEncryption.encryptString(json, usertoken, authdata);
        }
    }

    // create feeder with credentials
    val feeder = jsonFile("credentials.json").queue;
    // create scenario
    object Auth {
        var device = new DeviceData();
        // pick user from feeder
        // and set username, password, and deviceId
        var pickUser = feed(feeder)
        // init request with feeder
        val checkSessionIsOn = exec(
                http("check_session_is_on")
                    .get("http://localhost/mobile/webservices/mobile")
                    .check(status.is(200))
            )

        val checkSessionIsOff = exec(
                http("check_session_is_off")
                    .get("http://localhost/mobile/webservices/mobile")
                    .check(status.is(401))
            )

        // login chain of requests
        val login = tryMax(2) {
            exec(
                http("requesting_onetime_token")
                    .post("http://localhost/mobile/webservices/Mobile/core/oneTimeLoginToken")
                    .headers(Map(
                        "Accept" -> "application/json, text/javascript, */*; q=0.01",
                        "Content-Type" -> "application/x-www-form-urlencoded; charset=UTF-8"
                        )
                    )
                    .body(StringBody(
                        Util.jsonFromMap(Map(
                            "DocumentType" -> "OneTimeLoginTokenRequestDocument",
                            "Username" -> "${username}",
                            "DeviceId" -> "${deviceId}",
                            "DeviceType" -> device.getType()
                        ))
                    ))
                    .check(status.is(200))
                    .check(bodyString.saveAs("mobile_response"))
            )
            .exec{ session =>
                var userToken = new UserToken(
                    session("username").asOption[String],
                    session("password").asOption[String]
                );
                //println(session("username").as[String] + "->" + session("password").as[String])
                val authdata = Actions.retrieveAuthData(session, "mobile_response");
                val encToken = MobileEncryption.encryptUserToken(userToken, authdata);
                session.set("mobile_encryptedUserToken", encToken);
            }
            .exec(
                http("sending_login_token")
                    .post("http://localhost/mobile/webservices/Mobile/core/sessions")
                    .body(StringBody(
                        Util.jsonFromMap(Map(
                            "DocumentType" -> "SessionCreationDocument",
                            "Username" -> "${username}",
                            "UserToken" -> "${mobile_encryptedUserToken}",
                            "DeviceInformation" -> Map(
                                "AdditionalInformation" -> device.getAddInfo(),
                                "DeviceModel" -> device.getVersion().toString,
                                "DeviceType" -> device.getType(),
                                "DeviceId" -> "${deviceId}"
                            )
                        ))
                    ))
                    .check(status.is(200))
            )
            .exec(
                http("checking_login_success")
                    .get("http://localhost/mobile/webservices/mobile")
                    .check(status.is(200))
            )
        }.exitHereIfFailed

        // logout - server side logging out + clearing all the cookies
        var logout = exec{ session =>
                var usertoken = new UserToken(
                    session("username").asOption[String],
                    session("password").asOption[String]
                );
                val authdata = new AuthData("");
                val encToken = MobileEncryption.encryptUserToken(usertoken, authdata);
                session.set("mobile_logoutToken", encToken);
            }
            .exec(
                http("logging_out")
                    .post("http://localhost/mobile/webservices/mobile/core/sessions/current")
                    .body(StringBody("${mobile_logoutToken}"))
                    .check(status.is(200))
            )
            .exec(flushSessionCookies)
    }

    object Browse {
        val serverPage = exec(
            http("server_page")
                .get("http://localhost/mobile/webservices/controlpanel/Server")
                .headers(Map(
                    "Accept" -> "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"
                    )
                )
                .check(status.is(200))
            )
            .pause(5, 15)

        val deviceManagement = exec(
            http("device_management")
                .get("http://localhost/mobile/webservices/controlpanel/DeviceManagement")
                .check(status.is(200))
            )
            .pause(5, 15)

        val analytics = exec(
            http("analytics")
                .get("http://localhost/mobile/webservices/controlpanel/Analytics")
                .check(status.is(200))
            )
            .pause(5, 15)

        val accessControl = exec(
            http("access_control")
                .get("http://localhost/mobile/webservices/controlpanel/AccessControl")
                .check(status.is(200))
            )
            .pause(5, 15)

        val userAdministration = exec(
            http("user_administration")
                .get("http://localhost/mobile/webservices/defaultuserplugin/users")
                .check(status.is(200))
            )
            .pause(5, 15)

        val createUser = exec { session =>
                var usertoken = new UserToken(session("username").asOption[String], session("password").asOption[String]);
                val authdata = Actions.retrieveAuthData(session, "mobile_response");
                session.set("mobile_createuser_msg", Actions.prepare(usertoken, authdata))
            }
            .exec(
                http("createUser")
                    .post("http://localhost/mobile/webservices/defaultuserplugin/users")
                    .body(StringBody("${mobile_createuser_msg}"))
                    .check(status.is(200))
            )
            .pause(5, 15)
    }

    val analyticsUsers = scenario("Analytics Users")
        .exec(Auth.pickUser)
        .repeat(8) {
            exec(
                Auth.checkSessionIsOff,
                Auth.login,
                Browse.analytics,
                Browse.accessControl,
                Browse.analytics,
                Browse.deviceManagement,
                Browse.analytics,
                Auth.logout
            )
        }

    val deviceManagementUsers = scenario("Device Management Users")
        .exec(Auth.pickUser)
        .repeat(8) {
            exec(
                Auth.checkSessionIsOff,
                Auth.login,
                Browse.accessControl,
                Browse.deviceManagement,
                Browse.serverPage,
                Browse.deviceManagement,
                Browse.userAdministration,
                Browse.deviceManagement,
                Auth.logout
            )
        }

    val adminUsers = scenario("Admin Users")
        .exec(Auth.pickUser)
        .repeat(8) {
            exec(
                Auth.checkSessionIsOff,
                Auth.login,
                Browse.serverPage,
                Browse.accessControl,
                Browse.userAdministration,
                Browse.deviceManagement,
                Browse.serverPage,
                Auth.logout
            )
        }
        .repeat(2) {
            exec(
                Auth.checkSessionIsOff,
                Auth.login,
                Browse.userAdministration,
                Browse.createUser,
                Auth.logout
            )
        }

    // set it all up
    setUp(
        analyticsUsers.inject(
            rampUsers(10) over (4 seconds)
        ),
        deviceManagementUsers.inject(
            rampUsers(8) over (3 seconds)
        ),
        adminUsers.inject(
            nothingFor(3 seconds),
            rampUsers(2) over (1 seconds)
        )
    ).protocols(httpConf)
}