admission-controller

README

G8S Admission Controller

Giant Swarm Control Plane admission controller that implements the following rules:

• In a G8sControlPlane resource, when the .spec.replicas is changed from 1 to 3, the Availability Zones of the according AWSControlPlane will be defaulted if needed.

• In a G8sControlPlane resource, the replicas attribute will be defaulted if it is not defined.

  • For HA-Versions, in case the matching AWSControlPlane already exists, the number of AZs determines the value of replicas. In case no such AWSControlPlane exists, the default number of AZs is assigned.
  • For pre-HA versions, replicas is always set to 1 for a single master cluster.

• In a G8sControlPlane resource, the infrastructure reference will be set to point to the matching AWSControlPlane resource if it already exists.

• In an AWSControlPlane resource, the Availability Zones will be defaulted if they are nil.

  • For HA-Versions, in case the matching G8sControlPlane already exists, the number of AZs is determined by the number of replicas defined there. In case no such G8sControlPlane exists, the default number of AZs is assigned.
  • For Pre-HA-Versions, in case the matching AWSCluster already exists, the AZ is taken from there.

• In an AWSControlPlane resource, the Instance Type will be defaulted if it is not defined.

  • For HA-Versions, the default Instance Type is chosen.
  • For Pre-HA-Versions, in case the matching AWSCluster already exists, the Instance Type is taken from there.

• On creation of an AWSControlPlane resource, the infrastructure reference of the according G8sControlPlane will be set if needed.

• When a new AWSMachineDeployment is created, details are logged.

The certificates for the webhook are created with CertManager and injected through the CA Injector.

Ownership

Firecracker Team

Local Development

Testing the admission-controller in a kind cluster on your local machine:

kind create cluster

# Build a linux image
CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build .
docker build . -t admission-controller:dev
kind load docker-image admission-controller:dev

# Make sure the Custom Resource Definitions are in place
opsctl ensure crds -k "$(kind get kubeconfig)" -p aws

# Insert the certificate
kubectl apply --context kind-kind -f local_dev/certmanager.yml

## Wait until certmanager is up

kubectl apply --context kind-kind -f local_dev/clusterissuer.yml
helm template admission-controller -f helm/admission-controller/ci/default-values.yaml helm/admission-controller > local_dev/deploy.yaml

## Replace image name with admission-controller:dev
kubectl apply --context kind-kind -f local_dev/deploy.yaml
kind delete cluster

Changelog

See Releases

Contact

• Bugs: issues
• Please visit https://www.giantswarm.io/responsible-disclosure for information on reporting security issues.

Contributing, reporting bugs

See CONTRIBUTING for details on submitting patches, the contribution workflow as well as reporting bugs.

Publishing a release

See docs/Release.md

Add a new webhook

See docs/webhook.md

Writing tests

See docs/tests.md