add PriorityClass (#148)

* add PriorityClass

* rename pc

* move to config

* extend retries

* add test for priorityClass in e2e-tests

* fix tests

* fix tests

* check for the right priorityClassName

config/manager/kustomization.yaml

@@ -11,6 +11,7 @@
 
 resources:
 - manager.yaml
+- priority-class.yaml
 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 images:

config/manager/priority-class.yaml

@@ -0,0 +1,7 @@
+apiVersion: scheduling.k8s.io/v1
+kind: PriorityClass
+metadata:
+  name: manager-priority-class
+value: 2000000
+globalDefault: false
+description: "Scheduling priority of the NATS-Manager module. Must not be blocked by unschedulable user workloads."

e2e/common/fixtures/fixtures.go

@@ -23,6 +23,7 @@ const (
 	FileStorageSize       = "1Gi"
 	MemStorageSize        = "1Gi"
 	True                  = "true"
+	PriorityClassName     = "nats-manager-priority-class"
 )
 
 func NATSCR() *natsv1alpha1.NATS {

e2e/setup/setup_test.go

@@ -33,8 +33,8 @@ import (
 
 // Constants for retries.
 const (
-	interval = 2 * time.Second
-	attempts = 60
+	interval = 3 * time.Second
+	attempts = 120
 )
 
 // clientSet is what is used to access K8s build-in resources like Pods, Namespaces and so on.
@@ -128,6 +128,34 @@ func Test_CR(t *testing.T) {
 	)
 }
 
+// Test_PriorityClass will get the PriorityClass name from the StatefulSet and checks if a PriorityClass with that
+// name exists in the cluster.
+func Test_PriorityClass(t *testing.T) {
+	ctx := context.TODO()
+
+	err := Retry(attempts, interval, func() error {
+		sts, stsErr := clientSet.AppsV1().StatefulSets(NamespaceName).Get(ctx, STSName, metav1.GetOptions{})
+		if stsErr != nil {
+			return stsErr
+		}
+
+		pcName := sts.Spec.Template.Spec.PriorityClassName
+		// todo remove this check after the next release.
+		if len(pcName) < 1 {
+			return nil
+		}
+
+		if pcName != PriorityClassName {
+			return fmt.Errorf("PriorityClassName was expected to be %s but was %s", PriorityClassName, pcName)
+		}
+
+		_, pcErr := clientSet.SchedulingV1().PriorityClasses().Get(ctx, pcName, metav1.GetOptions{})
+		return pcErr
+	})
+
+	require.NoError(t, err)
+}
+
 // Test_ConfigMap tests the ConfigMap that the NATS-Manger creates when we define a CR.
 func Test_ConfigMap(t *testing.T) {
 	ctx := context.TODO()

resources/nats/values.yaml

@@ -30,6 +30,8 @@ global:
     # when replacing pods on nodes, or when scaling down.
     podManagementPolicy: Parallel
 
+  priorityClassName: "nats-manager-priority-class"
+
 ####################################
 #                                  #
 #  Security Context Configuration  #