Advanced StatefulSet
This is an Advanced StatefulSet CRD implementation based on official StatefulSet in Kubernetes 1.17.0.
This is an experimental project.
Features
In addition to official StatefulSet, it adds one feature:
- Scale in at an arbitrary position: https://github.com/kubernetes/kubernetes/issues/83224
Development
Verify
make verify
Unit Tests
make test
Integration Tests
make test-integration
E2E
make e2e
Test it out
start a cluster
kind v0.7.0+ is recommended.
curl -Lo ./kind https://github.com/kubernetes-sigs/kind/releases/download/v0.7.0/kind-$(uname)-amd64
chmod +x ./kind
./kind create cluster
run advanced statefulset controller locally
Open a new terminal and run controller:
hack/local-up.sh
deploy a statefulset
kubectl apply -f examples/statefulset.yaml
scale out
Note that --resource-version is required for CRD objects.
RESOURCE_VERSION=$(kubectl get statefulsets.pingcap.com web -ojsonpath='{.metadata.resourceVersion}')
kubectl scale --resource-version=$RESOURCE_VERSION --replicas=4 statefulsets.pingcap.com web
scale in
RESOURCE_VERSION=$(kubectl get statefulsets.pingcap.com web -ojsonpath='{.metadata.resourceVersion}')
kubectl scale --resource-version=$RESOURCE_VERSION --replicas=3 statefulsets.pingcap.com web
scale in at arbitrary position
We should set delete-slots annotations and decrement spec.replicas at the
same time.
kubectl apply -f examples/scale-in-statefulset.yaml