fix(controller/pdb): set min available to zero replicas at least

controllers/controller.go

@@ -671,6 +671,10 @@ func newPDB(instance *v1alpha1.RpaasInstance, nginx *nginxv1alpha1.Nginx) (*poli
 		}
 	}
 
+	if minAvailable.IntValue() < 0 {
+		minAvailable = intstr.FromInt(0)
+	}
+
 	return &policyv1beta1.PodDisruptionBudget{
 		TypeMeta: metav1.TypeMeta{
 			APIVersion: "policy/v1beta1",

controllers/controller_test.go

@@ -1253,6 +1253,63 @@ func Test_reconcilePDB(t *testing.T) {
 				assert.True(t, k8serrors.IsNotFound(err))
 			},
 		},
+
+		"creating PDB when instance has 0 replicas": {
+			instance: &v1alpha1.RpaasInstance{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "my-instance",
+					Namespace: "rpaasv2",
+				},
+				Spec: v1alpha1.RpaasInstanceSpec{
+					EnablePodDisruptionBudget: func(b bool) *bool { return &b }(true),
+					Replicas:                  func(n int32) *int32 { return &n }(0),
+				},
+			},
+			nginx: &nginxv1alpha1.Nginx{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "my-instance",
+					Namespace: "rpaasv2",
+				},
+				Status: nginxv1alpha1.NginxStatus{
+					PodSelector: "nginx.tsuru.io/resource-name=my-instance",
+				},
+			},
+			assert: func(t *testing.T, c client.Client) {
+				var pdb policyv1beta1.PodDisruptionBudget
+				err := c.Get(context.TODO(), client.ObjectKey{Name: "my-instance", Namespace: "rpaasv2"}, &pdb)
+				require.NoError(t, err)
+				assert.Equal(t, policyv1beta1.PodDisruptionBudget{
+					TypeMeta: metav1.TypeMeta{
+						APIVersion: "policy/v1beta1",
+						Kind:       "PodDisruptionBudget",
+					},
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "my-instance",
+						Namespace: "rpaasv2",
+						Labels: map[string]string{
+							"rpaas.extensions.tsuru.io/instance-name": "my-instance",
+							"rpaas.extensions.tsuru.io/plan-name":     "",
+						},
+						ResourceVersion: "1",
+						OwnerReferences: []metav1.OwnerReference{
+							{
+								APIVersion:         "extensions.tsuru.io/v1alpha1",
+								Kind:               "RpaasInstance",
+								Name:               "my-instance",
+								Controller:         func(b bool) *bool { return &b }(true),
+								BlockOwnerDeletion: func(b bool) *bool { return &b }(true),
+							},
+						},
+					},
+					Spec: policyv1beta1.PodDisruptionBudgetSpec{
+						MinAvailable: func(n intstr.IntOrString) *intstr.IntOrString { return &n }(intstr.FromInt(0)),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{"nginx.tsuru.io/resource-name": "my-instance"},
+						},
+					},
+				}, pdb)
+			},
+		},
 	}
 
 	for name, tt := range tests {