@@ -33,9 +33,11 @@ import (
 var (
 	defaultTestConfig = Config{
 		ReloaderConfig: operator.ReloaderConfig{
-			Image:  "quay.io/prometheus-operator/prometheus-config-reloader:latest",
-			CPU:    "100m",
-			Memory: "25Mi",
+			Image:         "quay.io/prometheus-operator/prometheus-config-reloader:latest",
+			CPURequest:    "100m",
+			CPULimit:      "100m",
+			MemoryRequest: "50Mi",
+			MemoryLimit:   "50Mi",
 		},
 		AlertmanagerDefaultBaseImage: "quay.io/prometheus/alertmanager",
 	}
// Copyright 2016 The prometheus-operator Authors
//
// 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 alertmanager

import (
	"fmt"
	"reflect"
	"strings"
	"testing"

	monitoringv1 "github.com/prometheus-operator/prometheus-operator/pkg/apis/monitoring/v1"
	"github.com/prometheus-operator/prometheus-operator/pkg/operator"
	"github.com/stretchr/testify/require"
	v1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"github.com/kylelemons/godebug/pretty"
)

var (
	defaultTestConfig = Config{
		ReloaderConfig: operator.ReloaderConfig{
			Image:  "quay.io/prometheus-operator/prometheus-config-reloader:latest",
			CPU:    "100m",
			Memory: "25Mi",
		},
		AlertmanagerDefaultBaseImage: "quay.io/prometheus/alertmanager",
	}
)

func TestStatefulSetLabelingAndAnnotations(t *testing.T) {
	labels := map[string]string{
		"testlabel": "testlabelvalue",
	}
	annotations := map[string]string{
		"testannotation": "testannotationvalue",
		"kubectl.kubernetes.io/last-applied-configuration": "something",
		"kubectl.kubernetes.io/something":                  "something",
	}
	// kubectl annotations must not be on the statefulset so kubectl does
	// not manage the generated object
	expectedAnnotations := map[string]string{
		"testannotation": "testannotationvalue",
	}

	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{
			Labels:      labels,
			Annotations: annotations,
		},
	}, nil, defaultTestConfig)

	require.NoError(t, err)

	if !reflect.DeepEqual(labels, sset.Labels) {
		t.Log(pretty.Compare(labels, sset.Labels))
		t.Fatal("Labels are not properly being propagated to the StatefulSet")
	}

	if !reflect.DeepEqual(expectedAnnotations, sset.Annotations) {
		t.Log(pretty.Compare(expectedAnnotations, sset.Annotations))
		t.Fatal("Annotations are not properly being propagated to the StatefulSet")
	}
}

func TestStatefulSetStoragePath(t *testing.T) {
	labels := map[string]string{
		"testlabel": "testlabelvalue",
	}
	annotations := map[string]string{
		"testannotation": "testannotationvalue",
	}
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{
			Labels:      labels,
			Annotations: annotations,
		},
	}, nil, defaultTestConfig)

	require.NoError(t, err)

	reg := strings.Join(sset.Spec.Template.Spec.Containers[0].Args, " ")
	for _, k := range sset.Spec.Template.Spec.Containers[0].VolumeMounts {
		if k.Name == "config-volume" {
			if !strings.Contains(reg, k.MountPath) {
				t.Fatal("config-volume Path not configured correctly")
			} else {
				return
			}

		}
	}
	t.Fatal("config-volume not set")
}

func TestPodLabelsAnnotations(t *testing.T) {
	annotations := map[string]string{
		"testannotation": "testvalue",
	}
	labels := map[string]string{
		"testlabel": "testvalue",
	}
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{},
		Spec: monitoringv1.AlertmanagerSpec{
			PodMetadata: &monitoringv1.EmbeddedObjectMetadata{
				Annotations: annotations,
				Labels:      labels,
			},
		},
	}, nil, defaultTestConfig)
	require.NoError(t, err)
	if _, ok := sset.Spec.Template.ObjectMeta.Labels["testlabel"]; !ok {
		t.Fatal("Pod labes are not properly propagated")
	}
	if !reflect.DeepEqual(annotations, sset.Spec.Template.ObjectMeta.Annotations) {
		t.Fatal("Pod annotaitons are not properly propagated")
	}
}

func TestPodLabelsShouldNotBeSelectorLabels(t *testing.T) {
	labels := map[string]string{
		"testlabel": "testvalue",
	}
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{},
		Spec: monitoringv1.AlertmanagerSpec{
			PodMetadata: &monitoringv1.EmbeddedObjectMetadata{
				Labels: labels,
			},
		},
	}, nil, defaultTestConfig)

	require.NoError(t, err)

	if sset.Spec.Selector.MatchLabels["testlabel"] == "testvalue" {
		t.Fatal("Pod Selector are not properly propagated")
	}
}

func TestStatefulSetPVC(t *testing.T) {
	labels := map[string]string{
		"testlabel": "testlabelvalue",
	}
	annotations := map[string]string{
		"testannotation": "testannotationvalue",
	}

	storageClass := "storageclass"

	pvc := monitoringv1.EmbeddedPersistentVolumeClaim{
		EmbeddedObjectMetadata: monitoringv1.EmbeddedObjectMetadata{
			Annotations: annotations,
		},
		Spec: v1.PersistentVolumeClaimSpec{
			AccessModes:      []v1.PersistentVolumeAccessMode{v1.ReadWriteOnce},
			StorageClassName: &storageClass,
		},
	}

	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{
			Labels:      labels,
			Annotations: annotations,
		},
		Spec: monitoringv1.AlertmanagerSpec{
			Storage: &monitoringv1.StorageSpec{
				VolumeClaimTemplate: pvc,
			},
		},
	}, nil, defaultTestConfig)

	require.NoError(t, err)
	ssetPvc := sset.Spec.VolumeClaimTemplates[0]
	if !reflect.DeepEqual(*pvc.Spec.StorageClassName, *ssetPvc.Spec.StorageClassName) {
		t.Fatal("Error adding PVC Spec to StatefulSetSpec")
	}
}

func TestStatefulEmptyDir(t *testing.T) {
	labels := map[string]string{
		"testlabel": "testlabelvalue",
	}
	annotations := map[string]string{
		"testannotation": "testannotationvalue",
	}

	emptyDir := v1.EmptyDirVolumeSource{
		Medium: v1.StorageMediumMemory,
	}

	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{
			Labels:      labels,
			Annotations: annotations,
		},
		Spec: monitoringv1.AlertmanagerSpec{
			Storage: &monitoringv1.StorageSpec{
				EmptyDir: &emptyDir,
			},
		},
	}, nil, defaultTestConfig)

	require.NoError(t, err)
	ssetVolumes := sset.Spec.Template.Spec.Volumes
	if ssetVolumes[len(ssetVolumes)-1].VolumeSource.EmptyDir != nil && !reflect.DeepEqual(emptyDir.Medium, ssetVolumes[len(ssetVolumes)-1].VolumeSource.EmptyDir.Medium) {
		t.Fatal("Error adding EmptyDir Spec to StatefulSetSpec")
	}
}
func TestListenLocal(t *testing.T) {
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		Spec: monitoringv1.AlertmanagerSpec{
			ListenLocal: true,
		},
	}, nil, defaultTestConfig)
	if err != nil {
		t.Fatalf("Unexpected error while making StatefulSet: %v", err)
	}

	found := false
	for _, flag := range sset.Spec.Template.Spec.Containers[0].Args {
		if flag == "--web.listen-address=127.0.0.1:9093" {
			found = true
		}
	}

	if !found {
		t.Fatal("Alertmanager not listening on loopback when it should.")
	}

	if sset.Spec.Template.Spec.Containers[0].ReadinessProbe != nil {
		t.Fatal("Alertmanager readiness probe expected to be empty")
	}

	if sset.Spec.Template.Spec.Containers[0].LivenessProbe != nil {
		t.Fatal("Alertmanager readiness probe expected to be empty")
	}

	if len(sset.Spec.Template.Spec.Containers[0].Ports) != 2 {
		t.Fatal("Alertmanager container should only have one port defined")
	}
}

// below Alertmanager v0.13.0 all flags are with single dash.
func TestMakeStatefulSetSpecSingleDoubleDashedArgs(t *testing.T) {
	tests := []struct {
		version string
		prefix  string
		amount  int
	}{
		{"v0.12.0", "-", 1},
		{"v0.13.0", "--", 2},
	}

	for _, test := range tests {
		a := monitoringv1.Alertmanager{}
		a.Spec.Version = test.version
		replicas := int32(3)
		a.Spec.Replicas = &replicas

		statefulSet, err := makeStatefulSetSpec(&a, defaultTestConfig)
		if err != nil {
			t.Fatal(err)
		}

		amArgs := statefulSet.Template.Spec.Containers[0].Args

		for _, arg := range amArgs {
			if arg[:test.amount] != test.prefix {
				t.Fatalf("expected all args to start with %v but got %v", test.prefix, arg)
			}
		}
	}
}

func TestMakeStatefulSetSpecWebRoutePrefix(t *testing.T) {
	a := monitoringv1.Alertmanager{}
	replicas := int32(1)
	a.Spec.Version = operator.DefaultAlertmanagerVersion
	a.Spec.Replicas = &replicas

	statefulSet, err := makeStatefulSetSpec(&a, defaultTestConfig)
	if err != nil {
		t.Fatal(err)
	}

	amArgs := statefulSet.Template.Spec.Containers[0].Args

	containsWebRoutePrefix := false

	for _, arg := range amArgs {
		if strings.Contains(arg, "-web.route-prefix") {
			containsWebRoutePrefix = true
		}
	}

	if !containsWebRoutePrefix {
		t.Fatal("expected stateful set to contain arg '-web.route-prefix'")
	}
}

func TestMakeStatefulSetSpecPeersWithoutClusterDomain(t *testing.T) {
	replicas := int32(1)
	a := monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "alertmanager",
			Namespace: "monitoring",
		},
		Spec: monitoringv1.AlertmanagerSpec{
			Version:  "v0.15.3",
			Replicas: &replicas,
		},
	}

	statefulSet, err := makeStatefulSetSpec(&a, defaultTestConfig)
	if err != nil {
		t.Fatal(err)
	}

	found := false
	amArgs := statefulSet.Template.Spec.Containers[0].Args
	expectedArg := "--cluster.peer=alertmanager-alertmanager-0.alertmanager-operated:9094"
	for _, arg := range amArgs {
		if arg == expectedArg {
			found = true
		}
	}

	if !found {
		t.Fatalf("Cluster peer argument %v was not found in %v.", expectedArg, amArgs)
	}
}

func TestMakeStatefulSetSpecPeersWithClusterDomain(t *testing.T) {
	replicas := int32(1)
	a := monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "alertmanager",
			Namespace: "monitoring",
		},
		Spec: monitoringv1.AlertmanagerSpec{
			Version:  "v0.15.3",
			Replicas: &replicas,
		},
	}

	configWithClusterDomain := defaultTestConfig
	configWithClusterDomain.ClusterDomain = "custom.cluster"

	statefulSet, err := makeStatefulSetSpec(&a, configWithClusterDomain)
	if err != nil {
		t.Fatal(err)
	}

	found := false
	amArgs := statefulSet.Template.Spec.Containers[0].Args
	expectedArg := "--cluster.peer=alertmanager-alertmanager-0.alertmanager-operated.monitoring.svc.custom.cluster.:9094"
	for _, arg := range amArgs {
		if arg == expectedArg {
			found = true
		}
	}

	if !found {
		t.Fatalf("Cluster peer argument %v was not found in %v.", expectedArg, amArgs)
	}
}

func TestMakeStatefulSetSpecAdditionalPeers(t *testing.T) {
	a := monitoringv1.Alertmanager{}
	a.Spec.Version = "v0.15.3"
	replicas := int32(1)
	a.Spec.Replicas = &replicas
	a.Spec.AdditionalPeers = []string{"example.com"}

	statefulSet, err := makeStatefulSetSpec(&a, defaultTestConfig)
	if err != nil {
		t.Fatal(err)
	}

	peerFound := false
	amArgs := statefulSet.Template.Spec.Containers[0].Args
	for _, arg := range amArgs {
		if strings.Contains(arg, "example.com") {
			peerFound = true
		}
	}

	if !peerFound {
		t.Fatal("Additional peers were not found.")
	}
}

func TestAdditionalSecretsMounted(t *testing.T) {
	secrets := []string{"secret1", "secret2"}
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{},
		Spec: monitoringv1.AlertmanagerSpec{
			Secrets: secrets,
		},
	}, nil, defaultTestConfig)
	require.NoError(t, err)

	secret1Found := false
	secret2Found := false
	for _, v := range sset.Spec.Template.Spec.Volumes {
		if v.Secret != nil {
			if v.Secret.SecretName == "secret1" {
				secret1Found = true
			}
			if v.Secret.SecretName == "secret2" {
				secret2Found = true
			}
		}
	}

	if !(secret1Found && secret2Found) {
		t.Fatal("Additional secrets were not found.")
	}

	secret1Found = false
	secret2Found = false
	for _, v := range sset.Spec.Template.Spec.Containers[0].VolumeMounts {
		if v.Name == "secret-secret1" && v.MountPath == "/etc/alertmanager/secrets/secret1" {
			secret1Found = true
		}
		if v.Name == "secret-secret2" && v.MountPath == "/etc/alertmanager/secrets/secret2" {
			secret2Found = true
		}
	}

	if !(secret1Found && secret2Found) {
		t.Fatal("Additional secrets were not found.")
	}
}

func TestAlertManagerDefaultBaseImageFlag(t *testing.T) {
	alertManagerBaseImageConfig := Config{
		ReloaderConfig: operator.ReloaderConfig{
			Image:  "quay.io/prometheus-operator/prometheus-config-reloader:latest",
			CPU:    "100m",
			Memory: "25Mi",
		},
		AlertmanagerDefaultBaseImage: "nondefaultuseflag/quay.io/prometheus/alertmanager",
	}

	labels := map[string]string{
		"testlabel": "testlabelvalue",
	}
	annotations := map[string]string{
		"testannotation": "testannotationvalue",
	}

	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		ObjectMeta: metav1.ObjectMeta{
			Labels:      labels,
			Annotations: annotations,
		},
	}, nil, alertManagerBaseImageConfig)

	require.NoError(t, err)

	image := sset.Spec.Template.Spec.Containers[0].Image
	expected := "nondefaultuseflag/quay.io/prometheus/alertmanager" + ":" + operator.DefaultAlertmanagerVersion
	if image != expected {
		t.Fatalf("Unexpected container image.\n\nExpected: %s\n\nGot: %s", expected, image)
	}
}

func TestSHAAndTagAndVersion(t *testing.T) {
	{
		sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
			Spec: monitoringv1.AlertmanagerSpec{
				Tag:     "my-unrelated-tag",
				Version: "v0.15.3",
			},
		}, nil, defaultTestConfig)
		if err != nil {
			t.Fatalf("Unexpected error while making StatefulSet: %v", err)
		}

		image := sset.Spec.Template.Spec.Containers[0].Image
		expected := "quay.io/prometheus/alertmanager:my-unrelated-tag"
		if image != expected {
			t.Fatalf("Unexpected container image.\n\nExpected: %s\n\nGot: %s", expected, image)
		}
	}
	{
		sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
			Spec: monitoringv1.AlertmanagerSpec{
				SHA:     "7384a79f4b4991bf8269e7452390249b7c70bcdd10509c8c1c6c6e30e32fb324",
				Tag:     "my-unrelated-tag",
				Version: "v0.15.3",
			},
		}, nil, defaultTestConfig)
		if err != nil {
			t.Fatalf("Unexpected error while making StatefulSet: %v", err)
		}

		image := sset.Spec.Template.Spec.Containers[0].Image
		expected := "quay.io/prometheus/alertmanager@sha256:7384a79f4b4991bf8269e7452390249b7c70bcdd10509c8c1c6c6e30e32fb324"
		if image != expected {
			t.Fatalf("Unexpected container image.\n\nExpected: %s\n\nGot: %s", expected, image)
		}
	}
	{
		image := "my-registry/alertmanager:latest"
		sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
			Spec: monitoringv1.AlertmanagerSpec{
				SHA:     "7384a79f4b4991bf8269e7452390249b7c70bcdd10509c8c1c6c6e30e32fb324",
				Tag:     "my-unrelated-tag",
				Version: "v0.15.3",
				Image:   &image,
			},
		}, nil, defaultTestConfig)
		if err != nil {
			t.Fatalf("Unexpected error while making StatefulSet: %v", err)
		}

		resultImage := sset.Spec.Template.Spec.Containers[0].Image
		expected := "my-registry/alertmanager:latest"
		if resultImage != expected {
			t.Fatalf("Unexpected container image.\n\nExpected: %s\n\nGot: %s", expected, resultImage)
		}
	}
}

func TestRetention(t *testing.T) {
	tests := []struct {
		specRetention     string
		expectedRetention string
	}{
		{"", "120h"},
		{"1d", "1d"},
	}

	for _, test := range tests {
		sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
			Spec: monitoringv1.AlertmanagerSpec{
				Retention: test.specRetention,
			},
		}, nil, defaultTestConfig)
		if err != nil {
			t.Fatal(err)
		}

		amArgs := sset.Spec.Template.Spec.Containers[0].Args
		expectedRetentionArg := fmt.Sprintf("--data.retention=%s", test.expectedRetention)
		found := false
		for _, flag := range amArgs {
			if flag == expectedRetentionArg {
				found = true
				break
			}
		}

		if !found {
			t.Fatalf("expected Alertmanager args to contain %v, but got %v", expectedRetentionArg, amArgs)
		}
	}
}

func TestAdditionalConfigMap(t *testing.T) {
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		Spec: monitoringv1.AlertmanagerSpec{
			ConfigMaps: []string{"test-cm1"},
		},
	}, nil, defaultTestConfig)
	if err != nil {
		t.Fatalf("Unexpected error while making StatefulSet: %v", err)
	}

	cmVolumeFound := false
	for _, v := range sset.Spec.Template.Spec.Volumes {
		if v.Name == "configmap-test-cm1" {
			cmVolumeFound = true
		}
	}
	if !cmVolumeFound {
		t.Fatal("ConfigMap volume not found")
	}

	cmMounted := false
	for _, v := range sset.Spec.Template.Spec.Containers[0].VolumeMounts {
		if v.Name == "configmap-test-cm1" && v.MountPath == "/etc/alertmanager/configmaps/test-cm1" {
			cmMounted = true
		}
	}
	if !cmMounted {
		t.Fatal("ConfigMap volume not mounted")
	}
}

func TestSidecarsNoCPULimits(t *testing.T) {
	testConfig := Config{
		ReloaderConfig: operator.ReloaderConfig{
			Image:  "quay.io/prometheus-operator/prometheus-config-reloader:latest",
			CPU:    "0",
			Memory: "25Mi",
		},
		AlertmanagerDefaultBaseImage: "quay.io/prometheus/alertmanager",
	}
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		Spec: monitoringv1.AlertmanagerSpec{},
	}, nil, testConfig)
	if err != nil {
		t.Fatalf("Unexpected error while making StatefulSet: %v", err)
	}

	expectedResources := v1.ResourceRequirements{
		Limits: v1.ResourceList{
			v1.ResourceMemory: resource.MustParse("25Mi"),
		},
		Requests: v1.ResourceList{
			v1.ResourceMemory: resource.MustParse("25Mi"),
		},
	}
	for _, c := range sset.Spec.Template.Spec.Containers {
		if c.Name == "config-reloader" && !reflect.DeepEqual(c.Resources, expectedResources) {
			t.Fatalf("Expected resource requests/limits:\n\n%s\n\nGot:\n\n%s", expectedResources.String(), c.Resources.String())
		}
	}
}

func TestSidecarsNoMemoryLimits(t *testing.T) {
	testConfig := Config{
		ReloaderConfig: operator.ReloaderConfig{
			Image:  "quay.io/prometheus-operator/prometheus-config-reloader:latest",
			CPU:    "100m",
			Memory: "0",
		},
		AlertmanagerDefaultBaseImage: "quay.io/prometheus/alertmanager",
	}
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		Spec: monitoringv1.AlertmanagerSpec{},
	}, nil, testConfig)
	if err != nil {
		t.Fatalf("Unexpected error while making StatefulSet: %v", err)
	}

	expectedResources := v1.ResourceRequirements{
		Limits: v1.ResourceList{
			v1.ResourceCPU: resource.MustParse("100m"),
		},
		Requests: v1.ResourceList{
			v1.ResourceCPU: resource.MustParse("100m"),
		},
	}
	for _, c := range sset.Spec.Template.Spec.Containers {
		if c.Name == "config-reloader" && !reflect.DeepEqual(c.Resources, expectedResources) {
			t.Fatalf("Expected resource requests/limits:\n\n%s\n\nGot:\n\n%s", expectedResources.String(), c.Resources.String())
		}
	}
}

func TestTerminationPolicy(t *testing.T) {
	sset, err := makeStatefulSet(&monitoringv1.Alertmanager{
		Spec: monitoringv1.AlertmanagerSpec{},
	}, nil, defaultTestConfig)
	if err != nil {
		t.Fatalf("Unexpected error while making StatefulSet: %v", err)
	}

	for _, c := range sset.Spec.Template.Spec.Containers {
		if c.TerminationMessagePolicy != v1.TerminationMessageFallbackToLogsOnError {
			t.Fatalf("Unexpected TermintationMessagePolicy. Expected %v got %v", v1.TerminationMessageFallbackToLogsOnError, c.TerminationMessagePolicy)
		}
	}
}

func TestClusterListenAddressForSingleReplica(t *testing.T) {
	a := monitoringv1.Alertmanager{}
	replicas := int32(1)
	a.Spec.Version = operator.DefaultAlertmanagerVersion
	a.Spec.Replicas = &replicas

	statefulSet, err := makeStatefulSetSpec(&a, defaultTestConfig)
	if err != nil {
		t.Fatal(err)
	}

	amArgs := statefulSet.Template.Spec.Containers[0].Args

	containsEmptyClusterListenAddress := false

	for _, arg := range amArgs {
		if arg == "--cluster.listen-address=" {
			containsEmptyClusterListenAddress = true
		}
	}

	if !containsEmptyClusterListenAddress {
		t.Fatal("expected stateful set to contain arg '--cluster.listen-address='")
	}
}

func TestClusterListenAddressForSingleReplicaWithForceEnableClusterMode(t *testing.T) {
	a := monitoringv1.Alertmanager{}
	replicas := int32(1)
	a.Spec.Version = operator.DefaultAlertmanagerVersion
	a.Spec.Replicas = &replicas
	a.Spec.ForceEnableClusterMode = true

	statefulSet, err := makeStatefulSetSpec(&a, defaultTestConfig)
	if err != nil {
		t.Fatal(err)
	}

	amArgs := statefulSet.Template.Spec.Containers[0].Args

	containsEmptyClusterListenAddress := false

	for _, arg := range amArgs {
		if arg == "--cluster.listen-address=" {
			containsEmptyClusterListenAddress = true
		}
	}

	if containsEmptyClusterListenAddress {
		t.Fatal("expected stateful set to not contain arg '--cluster.listen-address='")
	}
}

func TestClusterListenAddressForMultiReplica(t *testing.T) {
	a := monitoringv1.Alertmanager{}
	replicas := int32(3)
	a.Spec.Version = operator.DefaultAlertmanagerVersion
	a.Spec.Replicas = &replicas

	statefulSet, err := makeStatefulSetSpec(&a, defaultTestConfig)
	if err != nil {
		t.Fatal(err)
	}

	amArgs := statefulSet.Template.Spec.Containers[0].Args

	containsClusterListenAddress := false

	for _, arg := range amArgs {
		if arg == "--cluster.listen-address=[$(POD_IP)]:9094" {
			containsClusterListenAddress = true
		}
	}

	if !containsClusterListenAddress {
		t.Fatal("expected stateful set to contain arg '--cluster.listen-address=[$(POD_IP)]:9094'")
	}
}

All tests that specify resources utilize "50Mi" for memory so I've bumped the defaultTestConfig to match.