fleet/infrastructure/loadtesting/terraform/readme.md

## 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).
1. arm64 (M1/M2/etc) Mac Only: run `helpers/setup-darwin_arm64.sh` to build terraform plugins that lack arm64 builds in the registry.  Alternatively, you can use the amd64 terraform binary, which works with Rosetta 2.
1. Log into AWS SSO on `loadtesting` via `aws sso login`. (If you have multiple profiles, export the `AWS_PROFILE` variable.) For configuration, see `infrastructure/sso` folder's readme in the `confidential` private repo.
1. Initialize your terraform environment with `terraform init`.
1. Select a workspace for your test: `terraform workspace new WORKSPACE-NAME; terraform workspace select WORKSPACE-NAME`. Ensure your `WORKSPACE-NAME` is less than or equal to 17 characters and contains only alphanumeric characters and hyphens, as it is used to generate names for AWS resources.
1. 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, > ~30m). You should always use a branch other than `main` (Branch `main` changes often and it might trigger rebuilts of the images.) Note that for a few minutes after `terraform apply`, the Fleet instances may be failing to start with a permission issue (to read a database secret), but this should resolve automatically after a bit and ECS will begin to start the Fleet instances, but they may still fail due to missing database migrations (this will show up in the instances' logs). At this point you can move on to the next step.
1. Run database migrations (see [Running migrations](#running-migrations)). You will get 500 errors and your containers will not run if you do not do this. After running this step, you might need to wait a few minutes until the environment is up and running.
1. Perform your tests (see [Running a loadtest](#running-a-loadtest)). Your deployment will be available at `https://WORKSPACE-NAME.loadtest.fleetdm.com`. Reach out to the infrastructure team to get the credentials to log in.
1. When you're done, clean up the environment with `terraform destroy` (it will prompt for the branch name). If A destroy fails, see [ECR Cleanup Troubleshooting](#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)"}"`

### MDM

If you need to run a load test with MDM enabled and configured you will need to set MDM certificates, keys and tokens to the Fleet configuration.

1. Place the files in a known location:
```sh
/Users/foobar/mdm/fleet-mdm-apple-scep.crt
/Users/foobar/mdm/fleet-mdm-apple-scep.key

/Users/foobar/mdm/mdmcert.download.push.pem
/Users/foobar/mdm/mdmcert.download.push.key

/Users/foobar/mdm/downloadtoken.p7m

/Users/foobar/mdm/fleet-apple-mdm-bm-public-key.crt
/Users/foobar/mdm/fleet-apple-mdm-bm-private.key
```

2. Then set the `fleet_config` terraform var the following way (make sure to add any extra configuration you need to this JSON):
```sh
export TF_VAR_fleet_config='{"FLEET_DEV_MDM_APPLE_DISABLE_PUSH":"1","FLEET_MDM_APPLE_SCEP_CHALLENGE":"foobar","FLEET_MDM_APPLE_SCEP_CERT_BYTES":"'$(cat /Users/foobar/mdm/fleet-mdm-apple-scep.crt | gsed -z 's/\n/\\n/g')'","FLEET_MDM_APPLE_SCEP_KEY_BYTES":"'$(cat /Users/foobar/mdm/fleet-mdm-apple-scep.key | gsed -z 's/\n/\\n/g')'","FLEET_MDM_APPLE_APNS_CERT_BYTES":"'$(cat /Users/foobar/mdm/mdmcert.download.push.pem | gsed -z 's/\n/\\n/g')'","FLEET_MDM_APPLE_APNS_KEY_BYTES":"'$(cat /Users/foobar/mdm/mdmcert.download.push.key | gsed -z 's/\n/\\n/g')'","FLEET_MDM_APPLE_BM_SERVER_TOKEN_BYTES":"'$(cat /Users/foobar/mdm/downloadtoken.p7m | gsed -z 's/\n/\\n/g' | gsed 's/"smime\.p7m"/\\"smime.p7m\\"/g' | tr -d '\r\n')'","FLEET_MDM_APPLE_BM_CERT_BYTES":"'$(cat /Users/foobar/mdm/fleet-apple-mdm-bm-public-key.crt | gsed -z 's/\n/\\n/g')'","FLEET_MDM_APPLE_BM_KEY_BYTES":"'$(cat /Users/foobar/mdm/fleet-apple-mdm-bm-private.key | gsed -z 's/\n/\\n/g')'"}'
```

- The above is needed because the newline characters in the certificate/key/token files.
- The value set in `FLEET_MDM_APPLE_SCEP_CHALLENGE` must match whatever you set in `osquery-perf`'s `mdm_scep_challenge` argument. 
- The above `export TF_VAR_fleet_config=...` command was tested on `bash`. It did not work in `zsh`.
- Note that we are also setting `FLEET_DEV_MDM_APPLE_DISABLE_PUSH=1`. We don't want to generate push notifications against fake UUIDs (otherwise it may cause Apple to rate limit due to invalid requests).
This has an impact on real devices because they will not be notified of any command to execute (it may take a reboot for them to reach out to Fleet for more commands).

3. Add the following `osquery-perf` arguments to [loadtesting.tf](./loadtesting.tf)
- `-mdm_prob 1.0`
- `-mdm_scep_challenge` set to the same value as `FLEET_MDM_APPLE_SCEP_CHALLENGE` above.

### Running a loadtest

We run simulated hosts in containers of 500 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 500 hosts you want to start. In the example above, it will run 4000. 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](https://us-east-2.console.aws.amazon.com/vpc/home?region=us-east-2#SecurityGroup:groupId=sg-0e67d910a662720f8) 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

#### Using a release tag instead of a branch

Since the tag name on Dockerhub doesn't match the tag name on GitHub, this presents a special use case when wanting to deploy a release tag.  In this case, you can use the optional `-var github_branch` in order to specify the separate tag.  For example, you would use the following to deploy a loadtest of version 4.28.0:

`terraform apply -var tag=v4.28.0 -var github_branch=fleet-v4.28.0 -var loadtest_containers=8`

#### 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`