Dartboard

A tool to run scalability and performance tests on the Rancher product family.

Supports deploying to AWS and Azure or a local Docker daemon (via k3d) for infrastructure; k3s, RKE2 and AKS as Kubernetes distributions; any recent version of Rancher.

Usage

• create a Definition of Alacritous and Repeatable Test (or dart) YAML file by adapting one of the examples in darts
• dartboard deploy --dart=./darts/my_dart.yaml will:
  • deploy (virtual) infrastructure via OpenTofu: the cluster Rancher runs on ("upstream"), clusters managed by Rancher ("downstream") and a special "tester" cluster where load generation and monitoring software runs
  • deploy and configure Rancher
  • execute load tests via k6
• dartboard destroy destroys all infrastructure

Special cases:

• dartboard apply only runs tofu apply without configuring any software (Rancher, load generation, monitoring...)
• dartboard load only runs k6 load tests assuming Rancher has already been deployed
• dartboard get-access returns details to access the created clusters and applications

To recreate environments:

• dartboard reapply runs destroy and then apply, tearing down and recreating test configuration infrastructure without any software (Rancher, load generation, moniroting...)
• dartboard redeploy runs destroy and then deploy, tearing down and recreating the full environment, infrastructure and software (use this if unsure)

"Bring Your Own" AWS VPC

There is some manual configuration required in order to use an existing AWS VPC instead of having the tofu modules create a full set of networking resources.

1. Have an existing VPC with a DHCP options set configured so that DNS = "AmazonProvidedDNS".
2. Create three subnets, requirements are as follows:
   1. One subnet should contain the substring "public" (case-sensitive), and should be tagged with Tier = Public (case-sensitive)
   2. One subnet should contain the substring "private" (case-sensitive), and should be tagged with Tier = Private (case-sensitive)
   3. One subnet should contain the substring "secondary-private" (case-sensitive), and should be tagged with Tier = SecondaryPrivate (case-sensitive)
   4. Each subnet should be assigned to the VPC you intend to use

Once these resources are manually setup, you can set the existing_vpc_name tofu variable in your Dart file and deploy as you normally would.

Installation

Download and unpack a release, it's a self-contained binary.

Test history

See the docs directory for a list of tests that were run with previous versions of this code and their results.

Common Troubleshooting

k3d: cluster not created

If you get this error from tofu apply:

Error: Failed Cluster Start: Failed to add one or more agents: Node k3d-... failed to get ready: error waiting for log line `successfully registered node` from node 'k3d-st-upstream-agent-0': stopped returning log lines: node k3d-... is running=true in status=restarting

And docker logs on the node container end with:

kubelet.go:1361] "Failed to start cAdvisor" err="inotify_init: too many open files"

Then you might need to increase inotify's maximum open file counts via:

echo 256 > /proc/sys/fs/inotify/max_user_instances
echo "fs.inotify.max_user_instances = 256" > /etc/sysctl.d/99-inotify-mui.conf

Kubernetes cluster unreachable

If you get this error from tofu apply:

│ Error: Kubernetes cluster unreachable: Get "https://upstream.local.gd:6443/version": dial tcp 127.0.0.1:6443: connect: connection refused

SSH tunnels might be broken. Reopen them via:

./config/open-tunnels-to-upstream-*.sh

OpenTofu extended logging

In case OpenTofu returns an error with little context about what happened, use the following to get more complete debugging output:

export TF_LOG=debug

Forcibly stopping all SSH tunnels

pkill -f 'ssh .*-o IgnoreUnknown=TofuCreatedThisTunnel.*'

Troubleshooting inaccessible Azure VMs

If an Azure VM is not accessible via SSH, try the following:

• add the boot_diagnostics = true option in inputs.tf
• apply or re-deploy
• in the Azure Portal, click on Home -> Virtual Machines -> -> Help -> Reset Password
• then Home -> Virtual Machines -> -> Help -> Serial Console

That should give you access to the VM's console, where you can log in with the new password and troubleshoot.

Tips

Use k3d targeting a remote machine running the Docker daemon

Use the following command to point to a remote Docker host:

export DOCKER_HOST=tcp://remotehost:remoteport

Note that the host has to have TCP socket enabled, in addition or replacing the default Unix socket.

Eg. on SUSE OSs edit the /etc/sysconfig/docker file as root and add or edit the following line:

DOCKER_OPTS="-H unix:///var/run/docker.sock -H tcp://127.0.0.1:2375"

If you access the Docker host via SSH, you might want to forward the Docker port along with any relevant ports to access Rancher and the clusters' Kubernetes APIs, for example:

ssh remotehost -L 2375:localhost:2375 -L 8443:localhost:8443 $(for KUBEPORT in $(seq 6445 1 6465); do echo " -L ${KUBEPORT}:localhost:${KUBEPORT}" ; done | tr -d "\n")

Use custom-built Rancher images on k3d

When using k3d, change RANCHER_IMAGE_TAG and if an image with the same tag is found it will be added to relevant clusters.

This is useful during Rancher development to test Rancher changes on k3d clusters.