This sample application uses the Locust open source load testing tool to create a simple load generator for your applications. The sample test definition locustfile.py tests the root of an endpoint passed in as an environment variable (TARGET_URL). For more information on the format of the test definition file, see Writing a locustfile.

You can get started using the following steps:

1. Install the AWS Elastic Beanstalk Command Line Interface (CLI).
2. Create an IAM Instance Profile named aws-elasticbeanstalk-locust-role with the policy in policy.json. For more information on how to create an IAM Instance Profile, see Create an IAM Instance Profile for Your Amazon EC2 Instances.
3. Run eb init -r <region> -p "Java 8" to initialize the folder for use with the CLI. Replace <region> with a region identifier such as us-west-2 (see Regions and Endpoints for a full list of region identifiers). For interactive mode, run eb init then, 1. Pick a region of your choice. 2. Select the [ Create New Application ] option. 3. Enter the application name of your choice. 4. Answer no to It appears you are using Python. Is this correct?. 5. Select Java as the platform. 6. Select Java 8 as the platform version. 7. Choose whether you want SSH access to the Amazon EC2 instances.
   Note: If you choose to enable SSH and do not have an existing SSH key stored on AWS, the EB CLI requires ssh-keygen to be available on the path to generate SSH keys.
4. Run eb create -i c3.large --scale 1 --envvars TARGET_URL=<test URL> --instance_profile aws-elasticbeanstalk-locust-role to begin the creation of your load generation environment. Replace <test URL> with the URL of the web app that you want to test. 1. Enter the environment name of your choice. 2. Enter the CNAME prefix you want to use for this environment.
5. Once the environment creation process completes, run eb open to open the Locust dashboard and start your tests.
6. To make changes to the test definition, edit the locustfile.py, save and commit the changes, and run eb deploy.
7. If you'd like to scale out the environment to more than 1 EC2 instance, 1. Run eb config, it'll open the configuration file in the default editor. 2. Set the BatchSize option under the aws:elasticbeanstalk:command namespace to 100. 3. Save the configuration file and exit the editor. This will start the environment update. 4. After the update completes, run eb scale <number of instances>. Replace <number of instances> with the number of EC2 instances you would like the environment to scale out to. 5. After the additional instances have been added, run eb deploy to reselect the master instance. 6. Run eb open to open the Locust dashboard and start your tests.
8. When you are done with your tests, run eb terminate --all to clean up.

Note: Running Locust in distributed mode requires a master/slave architecture. The sample application selects a master on each deployment, which requires eb deploy to be run after you change the number of instances running in the environment. Also, this sample requires that the auto scaling minimum and maximum be set to the same value