Add support for pod disruption budget

Author: aledbf

install/installer/pkg/common/pod_disruption_budget.go

@@ -0,0 +1,28 @@
+// Copyright (c) 2021 Gitpod GmbH. All rights reserved.
+// Licensed under the GNU Affero General Public License (AGPL).
+// See License.AGPL.txt in the project root for license information.
+
+package common
+
+import (
+	"fmt"
+
+	policy "k8s.io/api/policy/v1"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/intstr"
+)
+
+func PodDisruptionBudget(context *RenderContext, component string, maxUnavailable int, selector *v1.LabelSelector) *policy.PodDisruptionBudget {
+	muCount := intstr.FromInt(maxUnavailable)
+
+	return &policy.PodDisruptionBudget{
+		ObjectMeta: v1.ObjectMeta{
+			Name:      fmt.Sprintf("%v-pdb", component),
+			Namespace: context.Namespace,
+		},
+		Spec: policy.PodDisruptionBudgetSpec{
+			MaxUnavailable: &muCount,
+			Selector:       selector,
+		},
+	}
+}

install/installer/pkg/components/ws-manager-mk2/objects.go

@@ -15,6 +15,7 @@ var Objects common.RenderFunc = func(cfg *common.RenderContext) ([]runtime.Objec
 		crd,
 		configmap,
 		deployment,
+		pdb,
 		networkpolicy,
 		role,
 		rolebinding,

install/installer/pkg/components/ws-manager-mk2/pdb.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2021 Gitpod GmbH. All rights reserved.
+// Licensed under the GNU Affero General Public License (AGPL).
+// See License-AGPL.txt in the project root for license information.
+
+package wsmanagermk2
+
+import (
+	"github.com/gitpod-io/gitpod/installer/pkg/common"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+func pdb(ctx *common.RenderContext) ([]runtime.Object, error) {
+	return []runtime.Object{
+		common.PodDisruptionBudget(ctx, Component, 1, &metav1.LabelSelector{
+			MatchLabels: common.DefaultLabels(Component),
+		}),
+	}, nil
+}