Add custom sidecar containers pod extension

apis/mattermost/v1beta1/mattermost_types.go

@@ -286,11 +286,19 @@ type UpdateJob struct {
 
 // PodExtensions specify customized extensions for a pod.
 type PodExtensions struct {
-	// Additional InitContainers injected to pods.
+	// Additional InitContainers injected into pods.
 	// The setting does not override InitContainers defined by the Operator.
 	InitContainers []v1.Container `json:"initContainers,omitempty"`
 
-	// Additional Container Ports injected to pod's main container.
+	// Additional sidecar containers injected into pods.
+	// The setting does not override any sidecar containers defined by the Operator.
+	// Note that sidecars are injected as standard pod containers alongside the
+	// Mattermost application server. In the future, this may be migrated to
+	// use the currently-feature-gated init container method introduced in k8s v1.28:
+	// https://kubernetes.io/blog/2023/08/25/native-sidecar-containers/
+	SidecarContainers []v1.Container `json:"sidecarContainers,omitempty"`
+
+	// Additional Container Ports injected into pod's main container.
 	// The setting does not override ContainerPorts defined by the Operator.
 	ContainerPorts []v1.ContainerPort `json:"containerPorts,omitempty"`
 }

pkg/mattermost/mattermost_v1beta.go

@@ -366,6 +366,28 @@ func GenerateDeploymentV1Beta(mattermost *mmv1beta.Mattermost, db DatabaseConfig
 		revisionHistoryLimit = mattermost.Spec.DeploymentTemplate.RevisionHistoryLimit
 	}
 
+	containers := []corev1.Container{
+		{
+			Name:                     mattermostv1alpha1.MattermostAppContainerName,
+			Image:                    containerImage,
+			ImagePullPolicy:          mattermost.Spec.ImagePullPolicy,
+			TerminationMessagePolicy: corev1.TerminationMessageFallbackToLogsOnError,
+			Command:                  []string{"mattermost"},
+			Env:                      envVars,
+			Ports:                    containerPorts,
+			ReadinessProbe:           readiness,
+			LivenessProbe:            liveness,
+			VolumeMounts:             volumeMounts,
+			Resources:                mattermost.Spec.Scheduling.Resources,
+			SecurityContext:          containerSecurityContext,
+		},
+	}
+
+	// Final container extensions
+	if mattermost.Spec.PodExtensions.SidecarContainers != nil {
+		containers = append(containers, mattermost.Spec.PodExtensions.SidecarContainers...)
+	}
+
 	return &appsv1.Deployment{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:            deploymentName,
@@ -394,30 +416,15 @@ func GenerateDeploymentV1Beta(mattermost *mmv1beta.Mattermost, db DatabaseConfig
 				Spec: corev1.PodSpec{
 					ServiceAccountName: serviceAccountName,
 					InitContainers:     initContainers,
-					Containers: []corev1.Container{
-						{
-							Name:                     mattermostv1alpha1.MattermostAppContainerName,
-							Image:                    containerImage,
-							ImagePullPolicy:          mattermost.Spec.ImagePullPolicy,
-							TerminationMessagePolicy: corev1.TerminationMessageFallbackToLogsOnError,
-							Command:                  []string{"mattermost"},
-							Env:                      envVars,
-							Ports:                    containerPorts,
-							ReadinessProbe:           readiness,
-							LivenessProbe:            liveness,
-							VolumeMounts:             volumeMounts,
-							Resources:                mattermost.Spec.Scheduling.Resources,
-							SecurityContext:          containerSecurityContext,
-						},
-					},
-					ImagePullSecrets: mattermost.Spec.ImagePullSecrets,
-					Volumes:          volumes,
-					DNSConfig:        mattermost.Spec.DNSConfig,
-					DNSPolicy:        mattermost.Spec.DNSPolicy,
-					Affinity:         mattermost.Spec.Scheduling.Affinity,
-					NodeSelector:     mattermost.Spec.Scheduling.NodeSelector,
-					Tolerations:      mattermost.Spec.Scheduling.Tolerations,
-					SecurityContext:  podSecurityContext,
+					Containers:         containers,
+					ImagePullSecrets:   mattermost.Spec.ImagePullSecrets,
+					Volumes:            volumes,
+					DNSConfig:          mattermost.Spec.DNSConfig,
+					DNSPolicy:          mattermost.Spec.DNSPolicy,
+					Affinity:           mattermost.Spec.Scheduling.Affinity,
+					NodeSelector:       mattermost.Spec.Scheduling.NodeSelector,
+					Tolerations:        mattermost.Spec.Scheduling.Tolerations,
+					SecurityContext:    podSecurityContext,
 				},
 			},
 		},

pkg/mattermost/mattermost_v1beta_test.go

@@ -804,7 +804,6 @@ func TestGenerateDeployment_V1Beta(t *testing.T) {
 			description            string
 			mmSpec                 mmv1beta.MattermostSpec
 			dbConfig               DatabaseConfig
-			fileStoreConfig        FileStoreConfig
 			expectedInitContainers []corev1.Container
 		}{
 			{
@@ -887,6 +886,50 @@ func TestGenerateDeployment_V1Beta(t *testing.T) {
 		}
 	})
 
+	t.Run("custom sidecar container pod extension", func(t *testing.T) {
+		dbConfig := &ExternalDBConfig{dbType: database.PostgreSQLDatabase, hasDBCheckURL: false}
+		customSideBarContainers := []corev1.Container{
+			{Image: "my-log-exporter-image", Name: "log-exporter"},
+			{Image: "my-audit-image", Name: "audit"},
+		}
+
+		for _, testCase := range []struct {
+			description               string
+			mmSpec                    mmv1beta.MattermostSpec
+			expectedSidecarContainers []corev1.Container
+		}{
+			{
+				description: "no custom sidebar containers",
+				mmSpec: mmv1beta.MattermostSpec{
+					PodExtensions: mmv1beta.PodExtensions{
+						SidecarContainers: nil,
+					},
+				},
+				expectedSidecarContainers: nil,
+			},
+			{
+				description: "custom sidebar containers",
+				mmSpec: mmv1beta.MattermostSpec{
+					PodExtensions: mmv1beta.PodExtensions{
+						SidecarContainers: customSideBarContainers,
+					},
+				},
+				expectedSidecarContainers: customSideBarContainers,
+			},
+		} {
+			t.Run(testCase.description, func(t *testing.T) {
+				mattermost := &mmv1beta.Mattermost{
+					Spec: testCase.mmSpec,
+				}
+				deployment := GenerateDeploymentV1Beta(mattermost, dbConfig, &ExternalFileStore{}, "", "", "", "image")
+				require.Equal(t, len(testCase.expectedSidecarContainers), len(deployment.Spec.Template.Spec.Containers)-1)
+				if testCase.mmSpec.PodExtensions.SidecarContainers != nil {
+					assert.Equal(t, testCase.expectedSidecarContainers, deployment.Spec.Template.Spec.Containers[1:])
+				}
+			})
+		}
+	})
+
 	t.Run("should set SiteURL env if ingress host provided", func(t *testing.T) {
 		mattermost := &mmv1beta.Mattermost{
 			Spec: mmv1beta.MattermostSpec{},