pdb.go

/*
Copyright 2020 The Kubermatic Kubernetes Platform contributors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package apiserver

import (
	"github.com/kubermatic/kubermatic/api/pkg/resources"
	"github.com/kubermatic/kubermatic/api/pkg/resources/reconciling"
	"k8s.io/apimachinery/pkg/util/intstr"

	policyv1beta1 "k8s.io/api/policy/v1beta1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

// PodDisruptionBudgetCreator returns a func to create/update the apiserver PodDisruptionBudget
func PodDisruptionBudgetCreator() reconciling.NamedPodDisruptionBudgetCreatorGetter {
	return func() (string, reconciling.PodDisruptionBudgetCreator) {
		return resources.ApiserverPodDisruptionBudgetName, func(pdb *policyv1beta1.PodDisruptionBudget) (*policyv1beta1.PodDisruptionBudget, error) {
			maxUnavailable := intstr.FromInt(1)
			pdb.Spec = policyv1beta1.PodDisruptionBudgetSpec{
				Selector: &metav1.LabelSelector{
					MatchLabels: resources.BaseAppLabels(name, nil),
				},
				// we can only specify maxUnavailable as minAvailable would block in case we have replicas=1. See https://github.com/kubernetes/kubernetes/issues/66811
				MaxUnavailable: &maxUnavailable,
			}

			return pdb, nil
		}
	}
}