CLOUDP-62444: Adopt functional approach for StatefulSet construction

pkg/apis/mongodb/v1/mongodb_types.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"strings"
 
+	"k8s.io/apimachinery/pkg/types"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
@@ -95,6 +97,10 @@ func (m MongoDB) ConfigMapName() string {
 	return m.Name + "-config"
 }
 
+func (m MongoDB) NamespacedName() types.NamespacedName {
+	return types.NamespacedName{Name: m.Name, Namespace: m.Namespace}
+}
+
 // GetFCV returns the feature compatibility version. If no FeatureCompatibilityVersion is specified.
 // It uses the major and minor version for whichever version of MongoDB is configured.
 func (m MongoDB) GetFCV() string {

pkg/controller/mongodb/build_statefulset_test.go

@@ -0,0 +1,68 @@
+package mongodb
+
+import (
+	"os"
+	"reflect"
+	"testing"
+
+	"github.com/mongodb/mongodb-kubernetes-operator/pkg/kube/probes"
+
+	mdbv1 "github.com/mongodb/mongodb-kubernetes-operator/pkg/apis/mongodb/v1"
+
+	"github.com/stretchr/testify/assert"
+	appsv1 "k8s.io/api/apps/v1"
+)
+
+func init() {
+
+	os.Setenv(preStopHookImageEnv, "pre-stop-hook-image")
+}
+
+func TestMultipleCalls_DoNotCauseSideEffects(t *testing.T) {
+	mdb := newTestReplicaSet()
+	stsFunc := buildStatefulSetModificationFunction(mdb)
+	sts := &appsv1.StatefulSet{}
+
+	t.Run("1st Call", func(t *testing.T) {
+		stsFunc(sts)
+		assertStatefulSetIsBuiltCorrectly(t, mdb, sts)
+	})
+	t.Run("2nd Call", func(t *testing.T) {
+		stsFunc(sts)
+		assertStatefulSetIsBuiltCorrectly(t, mdb, sts)
+	})
+	t.Run("3rd Call", func(t *testing.T) {
+		stsFunc(sts)
+		assertStatefulSetIsBuiltCorrectly(t, mdb, sts)
+	})
+}
+
+func assertStatefulSetIsBuiltCorrectly(t *testing.T, mdb mdbv1.MongoDB, sts *appsv1.StatefulSet) {
+	assert.Len(t, sts.Spec.Template.Spec.Containers, 2)
+	assert.Len(t, sts.Spec.Template.Spec.InitContainers, 1)
+	assert.Equal(t, mdb.ServiceName(), sts.Spec.ServiceName)
+	assert.Equal(t, mdb.Name, sts.Name)
+	assert.Equal(t, mdb.Namespace, sts.Namespace)
+	assert.Equal(t, appsv1.RollingUpdateStatefulSetStrategyType, sts.Spec.UpdateStrategy.Type)
+	assert.Equal(t, operatorServiceAccountName, sts.Spec.Template.Spec.ServiceAccountName)
+	assert.Len(t, sts.Spec.Template.Spec.Containers[0].Env, 1)
+	assert.Len(t, sts.Spec.Template.Spec.Containers[1].Env, 2)
+
+	agentContainer := sts.Spec.Template.Spec.Containers[0]
+	assert.Equal(t, "agent-image", agentContainer.Image)
+	probe := agentContainer.ReadinessProbe
+	assert.True(t, reflect.DeepEqual(probes.New(defaultReadiness()), *probe))
+	assert.Equal(t, int32(240), probe.FailureThreshold)
+	assert.Equal(t, int32(5), probe.InitialDelaySeconds)
+	assert.Len(t, agentContainer.VolumeMounts, 3)
+
+	mongodContainer := sts.Spec.Template.Spec.Containers[1]
+	assert.Equal(t, "mongo:4.2.2", mongodContainer.Image)
+	assert.NotNil(t, sts.Spec.Template.Spec.Containers[0].ReadinessProbe)
+	assert.Len(t, mongodContainer.VolumeMounts, 3)
+
+	initContainer := sts.Spec.Template.Spec.InitContainers[0]
+	assert.Equal(t, preStopHookName, initContainer.Name)
+	assert.Equal(t, "pre-stop-hook-image", initContainer.Image)
+	assert.Len(t, initContainer.VolumeMounts, 1)
+}