fleet/infrastructure/loadtesting/terraform

Terraform for Loadtesting Environment

The interface into this code is designed to be minimal. If you require changes beyond whats described here, contact @zwinnerman-fleetdm.

Deploying your code to the loadtesting environment

1. Push your branch to https://github.com/fleetdm/fleet and wait for the build to complete (https://github.com/fleetdm/fleet/actions).
2. Initialize your terraform environment with terraform init.
3. Select a workspace for your test: terraform workspace new WORKSPACE-NAME; terraform workspace select WORKSPACE-NAME. Ensure your WORKSPACE-NAME contains only alphanumeric characters and hyphens, as it is used to generate names for AWS resources.
4. Apply terraform with your branch name with terraform apply -var tag=BRANCH_NAME and type yes to approve execution of the plan. This takes a while to complete (many minutes).
5. Run database migrations (see Running migrations). You will get 500 errors and your containers will not run if you do not do this.
6. Perform your tests (see Running a loadtest). Your deployment will be available at https://WORKSPACE-NAME.loadtest.fleetdm.com.
7. When you're done, clean up the environment with terraform destroy. If A destroy fails, see ECR Cleanup Troubleshooting for the most common reason.

Running migrations

After applying terraform with the commands above and before performing your tests, run the following command: aws ecs run-task --region us-east-2 --cluster fleet-"$(terraform workspace show)"-backend --task-definition fleet-"$(terraform workspace show)"-migrate:"$(terraform output -raw fleet_migration_revision)" --launch-type FARGATE --network-configuration "awsvpcConfiguration={subnets="$(terraform output -raw fleet_migration_subnets)",securityGroups="$(terraform output -raw fleet_migration_security_groups)"}"

Running a loadtest

We run simulated hosts in containers of 5,000 at a time. Once the infrastructure is running, you can run the following command:

terraform apply -var tag=BRANCH_NAME -var loadtest_containers=8

With the variable loadtest_containers you can specify how many containers of 5,000 hosts you want to start. In the example above, it will run 40,000. If the fleet instances need special configuration, you can pass them as environment variables to the fleet_config terraform variable, which is a map, using the following syntax (note the use of single quotes around the whole fleet_config variable assignment, and the use of double quotes inside its map value):

terraform apply -var tag=BRANCH_NAME -var loadtest_containers=8 -var='fleet_config={"FLEET_OSQUERY_ENABLE_ASYNC_HOST_PROCESSING":"host_last_seen=true","FLEET_OSQUERY_ASYNC_HOST_COLLECT_INTERVAL":"host_last_seen=10s"}'

Monitoring the infrastructure

There are a few main places of interest to monitor the load and resource usage:

• The Application Performance Monitoring (APM) dashboard: access it on your Fleet load-testing URL on port :5601 and path /app/apm, e.g. https://loadtest.fleetdm.com:5601/app/apm. Note to do this without the VPN you will need to add your public IP Address to the load balancer for TCP Port 5601. At the time of this writing, this will take you directly to the security group for the load balancer if logged into the Load Testing account.
• The APM dashboard can also be accessed via private IP over the VPN. Use the following one-liner to get the URL: aws ec2 describe-instances --region=us-east-2 | jq -r '.Reservations[].Instances[] | select(.State.Name == "running") | select(.Tags[] | select(.Key == "ansible_playbook_file") | .Value == "elasticsearch.yml") | "http://" + .PrivateIpAddress + ":5601/app/apm"'. This connects directly to the EC2 instance and doesn't use the load balancer.
• To monitor mysql database load, go to AWS RDS, select "Performance Insights" and the database instance to monitor (you may want to turn off auto-refresh).
• To monitor Redis load, go to Amazon ElastiCache, select the redis cluster to monitor, and go to "Metrics".

Troubleshooting

General Troubleshooting

If terraform fails for some reason, you can make it output extra information to stderr by setting the TF_LOG environment variable to "DEBUG" or "TRACE", e.g.:

TF_LOG=DEBUG terraform apply ...

See https://www.terraform.io/internals/debugging for more details.

ECR Cleanup Troubleshooting

In a few instances, it is possible for an ECR repository to still have images left, preventing a full terraform destroy of a Loadtesting instance. Use the following one-liner to clean these up before re-running terraform destroy:

REPOSITORY_NAME=fleet-$(terraform workspace show); aws ecr list-images --repository-name ${REPOSITORY_NAME} --query 'imageIds[*]' --output text | while read digest tag; do aws ecr batch-delete-image --repository-name ${REPOSITORY_NAME} --image-ids imageDigest=${digest}; done