t4s

t4s

t4s is a simple tetris-like game implemented by Kubernetes controllers. Cluster users can play t****s in any time just by deploying a T4s resource.

Description

This is not a tetris-like application on the cluster, but the composite of CRDs and controllers interact each other to run t****s. All the information, such as the status of the game field and the descending block currently under control, are stored in custom resources and updated by reconciliation of the controllers.

Disclaimer

t4s may crush or slow down your cluster due to a heavy load on the control plane, especially if T4s resource is deployed on many namespaces. Do not deploy it to a production environment.

Quick start

1. Clone this repository
2. Create a kind cluster

$ make start

1. Deploy cert-manager

$ kubectl apply -f https://github.com/jetstack/cert-manager/releases/latest/download/cert-manager.yaml
$ kubectl -n cert-manager wait --for=condition=available --timeout=180s --all deployments

1. Deploy t4s controllers

$ kubectl apply -f https://github.com/tkna/t4s/releases/latest/download/t4s.yaml
$ kubectl -n t4s-system wait --for=condition=available --timeout=180s --all deployments

1. Deploy a T4s resource:

$ kubectl apply -f config/samples/t4s.yaml

1. Access http://localhost:18080/ with your web browser

Running on your cluster

1. Deploy cert-manager

$ kubectl apply -f https://github.com/jetstack/cert-manager/releases/latest/download/cert-manager.yaml
$ kubectl -n cert-manager wait --for=condition=available --timeout=180s --all deployments

2. Deploy t4s controllers

$ kubectl apply -f https://github.com/tkna/t4s/releases/latest/download/t4s.yaml
$ kubectl -n t4s-system wait --for=condition=available --timeout=180s --all deployments

3. Deploy T4s resource

Create and deploy a manifest like below:

• t4s.yaml

apiVersion: t4s.tkna.net/v1
kind: T4s
metadata:
  name: t4s-sample
spec:
  nodePort: 30080

$ kubectl apply -f t4s.yaml

By specifying nodePort, dedicated port will be exposed to the outside the cluster by the service t4s-app. If you are using a local kind cluster, extraPortMappings is required to be set in advance to access the nodeport from the localhost.

If you don't specify nodePort like below, an ephemeral port is automatically exposed by Kubernetes.

apiVersion: t4s.tkna.net/v1
kind: T4s
metadata:
  name: t4s-sample
spec: {}

If you are using a k8s cluster which has type: LoadBalancer for instance EKS/GKE, type: LoadBalancer is also available by specifying serviceType: LoadBalancer like below:

apiVersion: t4s.tkna.net/v1
kind: T4s
metadata:
  name: t4s-sample
spec:
  serviceType: LoadBalancer
  loadBalancerSourceRanges:           # loadBalancerSourceRanges is also available
  - XXX.XXX.XXX.XXX/YY                # range of your source IP

For EKS, only CLB(Classic Load Balancer) is supported at this point.

4. Look up the LoadBalancer IP or DNS name (if needed)

• EKS

Get the external-ip (DNS name) of the service "t4s-app".

$ kubectl get svc t4s-app
NAME      TYPE           CLUSTER-IP       EXTERNAL-IP                                              PORT(S)          AGE
t4s-app   LoadBalancer   10.100.195.228   xxxxxxxxxxxxxxxxxxxxx.ap-northeast-1.elb.amazonaws.com   8000:30949/TCP   20s

• GKE

Get the external-ip of service "t4s-app".

$ kubectl get svc t4s-app
NAME      TYPE           CLUSTER-IP     EXTERNAL-IP      PORT(S)          AGE
t4s-app   LoadBalancer   10.36.10.168   XXX.XXX.XXX.XXX   8000:32175/TCP   15m

5. Access with the browser

• Access http://<your-ip-or-DNS-name>:8000/
• Click "New Game"

Operation

Left arrow: left
Right arrow: right
Up arrow: rotate
Down arrow: down (soft drop)
Space key: drop (hard drop)

Limitation

• Only 1 T4s resource in a namespace
• No HTTPS support

Metrics

t4s outputs a custom metric called removed_rows_total_bucket in Prometheus histogram format. This metric allows you to monitor the counts per rows removed at once (normally 1...4) by namespace.

Development

• Create a kind cluster:

$ make start

• Launch tilt:

$ tilt up

• Tear down the kind cluster:

$ make stop

Testing

Test controllers

$ make test

E2E Test

$ cd e2e
$ make test

How it works

See docs directory.