feat: additional containers and volumes support (#345)

* feat: additional containers and volumes

add support for providing additional containers and volumes for dragonfly cluster pods

* feat: additional containers and volumes support

Author: iyuroch

api/v1alpha1/dragonfly_types.go

@@ -72,6 +72,16 @@ type DragonflySpec struct {
 	// +kubebuilder:validation:Optional
 	Env []corev1.EnvVar `json:"env,omitempty"`
 
+	// (Optional) Additional containers to add to dragonflycluster. Replace container on name collision.
+	// +optional
+	// +kubebuilder:validation:Optional
+	AdditionalContainers []corev1.Container `json:"additionalContainers,omitempty"`
+
+	// (Optional) Additional volumes to add to dragonflycluster. Replace volume on name collision.
+	// +optional
+	// +kubebuilder:validation:Optional
+	AdditionalVolumes []corev1.Volume `json:"additionalVolumes,omitempty"`
+
 	// (Optional) Dragonfly container resource limits. Any container limits
 	// can be specified.
 	// +optional

api/v1alpha1/zz_generated.deepcopy.go

@@ -25,6 +25,7 @@ import (
 	"encoding/pem"
 	"fmt"
 	"math/big"
+	"strings"
 	"time"
 
 	resourcesv1 "github.com/dragonflydb/dragonfly-operator/api/v1alpha1"
@@ -892,6 +893,114 @@ var _ = Describe("Dragonfly PVC Test with single replica", Ordered, FlakeAttempt
 	})
 })
 
+var _ = Describe("Dragonfly with additional container and volume", Ordered, FlakeAttempts(3), func() {
+	ctx := context.Background()
+	const (
+		name      = "df-addons"
+		namespace = "default"
+
+		sidecarName   = "helper"
+		sidecarImage  = "busybox:1.36"
+		volumeName    = "extra-storage"
+		volumeMountPt = "/opt/data"
+	)
+
+	Context("Create DF and verify additional resources are merged", func() {
+		It("Should create Dragonfly with an extra container and volume", func() {
+			df := &resourcesv1.Dragonfly{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      name,
+					Namespace: namespace,
+				},
+				Spec: resourcesv1.DragonflySpec{
+					Replicas: 1,
+					AdditionalContainers: []corev1.Container{
+						{
+							Name:    sidecarName,
+							Image:   sidecarImage,
+							Command: []string{"sh", "-c", "sleep 3600"},
+							VolumeMounts: []corev1.VolumeMount{
+								{Name: volumeName, MountPath: volumeMountPt},
+							},
+						},
+					},
+					AdditionalVolumes: []corev1.Volume{
+						{
+							Name: volumeName,
+							VolumeSource: corev1.VolumeSource{
+								EmptyDir: &corev1.EmptyDirVolumeSource{},
+							},
+						},
+					},
+				},
+			}
+			Expect(k8sClient.Create(ctx, df)).To(Succeed())
+		})
+
+		It("Resources should include the additional container and volume", func() {
+			// Wait for reconciliation to create SS and mark DF resources created
+			waitForDragonflyPhase(ctx, k8sClient, name, namespace, controller.PhaseResourcesCreated, 2*time.Minute)
+			waitForStatefulSetReady(ctx, k8sClient, name, namespace, 2*time.Minute)
+
+			// Fetch StatefulSet
+			var ss appsv1.StatefulSet
+			Expect(k8sClient.Get(ctx, types.NamespacedName{
+				Name:      name,
+				Namespace: namespace,
+			}, &ss)).To(Succeed())
+
+			// --- Verify additional container exists
+			containers := ss.Spec.Template.Spec.Containers
+			var helperIdx = -1
+			containerNames := make([]string, 0, len(containers))
+			for i, c := range containers {
+				containerNames = append(containerNames, c.Name)
+				if c.Name == sidecarName {
+					helperIdx = i
+				}
+			}
+			By("Listing containers: " + strings.Join(containerNames, ", "))
+			Expect(helperIdx).To(BeNumerically(">=", 0), "expected sidecar container %q to exist", sidecarName)
+
+			helper := containers[helperIdx]
+			Expect(helper.Image).To(Equal(sidecarImage))
+			// Check the volume mount by name + path (avoid brittle deep equality)
+			var hasMount bool
+			for _, vm := range helper.VolumeMounts {
+				if vm.Name == volumeName && vm.MountPath == volumeMountPt {
+					hasMount = true
+					break
+				}
+			}
+			Expect(hasMount).To(BeTrue(), "expected sidecar to mount %q at %q", volumeName, volumeMountPt)
+
+			// --- Verify additional volume exists
+			vols := ss.Spec.Template.Spec.Volumes
+			var volIdx = -1
+			volNames := make([]string, 0, len(vols))
+			for i, v := range vols {
+				volNames = append(volNames, v.Name)
+				if v.Name == volumeName {
+					volIdx = i
+				}
+			}
+			By("Listing volumes: " + strings.Join(volNames, ", "))
+			Expect(volIdx).To(BeNumerically(">=", 0), "expected volume %q to exist", volumeName)
+
+			Expect(vols[volIdx].EmptyDir).ToNot(BeNil(), "expected %q to be an EmptyDir", volumeName)
+		})
+
+		It("Cleanup", func() {
+			var df resourcesv1.Dragonfly
+			Expect(k8sClient.Get(ctx, types.NamespacedName{
+				Name:      name,
+				Namespace: namespace,
+			}, &df)).To(Succeed())
+			Expect(k8sClient.Delete(ctx, &df)).To(Succeed())
+		})
+	})
+})
+
 var _ = Describe("Dragonfly Server TLS tests", Ordered, FlakeAttempts(3), func() {
 	ctx := context.Background()
 	name := "df-tls"

config/crd/bases/dragonflydb.io_dragonflies.yaml

@@ -8,6 +8,7 @@ require (
 	github.com/onsi/gomega v1.36.1
 	github.com/pkg/errors v0.9.1
 	github.com/redis/go-redis/v9 v9.7.3
+	github.com/stretchr/testify v1.10.0
 	k8s.io/api v0.32.3
 	k8s.io/apimachinery v0.32.3
 	k8s.io/client-go v0.32.3
@@ -46,6 +47,7 @@ require (
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mxk/go-flowrate v0.0.0-20140419014527-cca7078d478f // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/prometheus/client_golang v1.21.1 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/common v0.63.0 // indirect

e2e/dragonfly_controller_test.go

@@ -369,6 +369,14 @@ func GenerateDragonflyResources(df *resourcesv1.Dragonfly) ([]client.Object, err
 		}
 	}
 
+	statefulset.Spec.Template.Spec.Containers = mergeNamedSlices(
+		statefulset.Spec.Template.Spec.Containers, df.Spec.AdditionalContainers,
+		func(c corev1.Container) string { return c.Name })
+
+	statefulset.Spec.Template.Spec.Volumes = mergeNamedSlices(
+		statefulset.Spec.Template.Spec.Volumes, df.Spec.AdditionalVolumes,
+		func(v corev1.Volume) string { return v.Name })
+
 	resources = append(resources, &statefulset)
 
 	serviceName := df.Name
@@ -458,6 +466,25 @@ func GenerateDragonflyResources(df *resourcesv1.Dragonfly) ([]client.Object, err
 	return resources, nil
 }
 
+// mergeNamedSlices will merge base into override, override takes precendence
+func mergeNamedSlices[T any](base, override []T, getName func(T) string) []T {
+	existing := make(map[string]bool, len(override))
+	for _, item := range override {
+		existing[getName(item)] = true
+	}
+
+	result := make([]T, len(override))
+	copy(result, override)
+
+	for _, item := range base {
+		if !existing[getName(item)] {
+			result = append(result, item)
+		}
+	}
+
+	return result
+}
+
 func generateResourceLabels(df *resourcesv1.Dragonfly) map[string]string {
 	return map[string]string{
 		KubernetesAppComponentLabelKey: KubernetesAppComponent,

go.mod

@@ -0,0 +1,69 @@
+package resources
+
+import (
+	"testing"
+
+	corev1 "k8s.io/api/core/v1"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMergeNamedSlices_Containers(t *testing.T) {
+	base := []corev1.Container{
+		{Name: "main", Image: "main:1"},
+		{Name: "sidecar", Image: "sidecar:1"},
+	}
+	override := []corev1.Container{
+		{Name: "main", Image: "main:custom"},
+		{Name: "metrics", Image: "metrics:1"},
+	}
+
+	result := mergeNamedSlices(base, override, func(c corev1.Container) string { return c.Name })
+
+	assert.Len(t, result, 3)
+	assert.Equal(t, "main:custom", result[0].Image)
+	assert.Equal(t, "metrics:1", result[1].Image)
+	assert.Equal(t, "sidecar:1", result[2].Image)
+}
+
+func TestMergeNamedSlices_Volumes(t *testing.T) {
+	base := []corev1.Volume{
+		{Name: "config"},
+		{Name: "data"},
+	}
+	override := []corev1.Volume{
+		{Name: "config"}, // override
+		{Name: "logs"},
+	}
+
+	result := mergeNamedSlices(base, override, func(v corev1.Volume) string { return v.Name })
+
+	assert.Len(t, result, 3)
+	assert.Equal(t, "config", result[0].Name)
+	assert.Equal(t, "logs", result[1].Name)
+	assert.Equal(t, "data", result[2].Name)
+}
+
+func TestMergeNamedSlices_EmptyOverride(t *testing.T) {
+	base := []corev1.Volume{
+		{Name: "default"},
+	}
+	override := []corev1.Volume{}
+
+	result := mergeNamedSlices(base, override, func(v corev1.Volume) string { return v.Name })
+
+	assert.Len(t, result, 1)
+	assert.Equal(t, "default", result[0].Name)
+}
+
+func TestMergeNamedSlices_EmptyBase(t *testing.T) {
+	base := []corev1.Container{}
+	override := []corev1.Container{
+		{Name: "user", Image: "user:1"},
+	}
+
+	result := mergeNamedSlices(base, override, func(c corev1.Container) string { return c.Name })
+
+	assert.Len(t, result, 1)
+	assert.Equal(t, "user", result[0].Name)
+}