feat: allow overriding kine container image via additionalContainers (#1254)

* feat: allow overriding kine container image via additionalContainers

Modify buildKine to preserve custom image if set, enabling per-tenant
kine image overrides using additionalContainers with name 'kine'.

* docs: add documentation for custom kine image override

* test: add kine container image override tests

* fix(docs): minor suggestion

---------

Co-authored-by: Dario Tranchitella <dario@tranchitella.eu>

docs/content/guides/alternative-datastore.md

@@ -12,6 +12,29 @@ The following `make` recipes help you to setup alternative `Datastore` resources
 
 - **NATS**: `$ make -C deploy/kine/nats nats`
 
+## Using a Custom Kine Image
+
+The default kine image can be overridden per-tenant by specifying a custom container image in the `additionalContainers` field:
+
+```yaml
+apiVersion: kamaji.clastix.io/v1alpha1
+kind: TenantControlPlane
+metadata:
+  name: tenant-name
+  namespace: kamaji-system
+spec:
+  controlPlane:
+    deployment:
+      additionalContainers:
+        - name: kine
+          image: custom-kine-image:tag
+```
+
+This is useful for:
+- Different database backends (postgresql, mysql, sqlite)
+- Custom kine builds with specific features
+- More granular control on a `TenantControlPlane` basis
+
 !!! warning "Not for production"
     The default settings are not production grade: the following scripts are just used to test the Kamaji usage of different drivers.
 

internal/builders/controlplane/deployment.go

@@ -960,7 +960,9 @@ func (d Deployment) buildKine(podSpec *corev1.PodSpec, tcp kamajiv1alpha1.Tenant
 		}
 
 		podSpec.InitContainers[index].Name = kineInitContainerName
-		podSpec.InitContainers[index].Image = d.KineContainerImage
+		if podSpec.InitContainers[index].Image == "" {
+			podSpec.InitContainers[index].Image = d.KineContainerImage
+		}
 		podSpec.InitContainers[index].Command = []string{"sh"}
 
 		podSpec.InitContainers[index].Args = []string{
@@ -1019,7 +1021,9 @@ func (d Deployment) buildKine(podSpec *corev1.PodSpec, tcp kamajiv1alpha1.Tenant
 	}
 
 	podSpec.Containers[index].Name = kineContainerName
-	podSpec.Containers[index].Image = d.KineContainerImage
+	if podSpec.Containers[index].Image == "" {
+		podSpec.Containers[index].Image = d.KineContainerImage
+	}
 	podSpec.Containers[index].Command = []string{"/bin/kine"}
 	podSpec.Containers[index].Args = utilities.ArgsFromMapToSlice(args)
 	podSpec.Containers[index].VolumeMounts = []corev1.VolumeMount{

internal/builders/controlplane/deployment_test.go

@@ -12,6 +12,7 @@ import (
 	pointer "k8s.io/utils/ptr"
 
 	kamajiv1alpha1 "github.com/clastix/kamaji/api/v1alpha1"
+	"github.com/clastix/kamaji/internal/utilities"
 )
 
 func TestControlplaneDeployment(t *testing.T) {
@@ -324,4 +325,68 @@ var _ = Describe("Controlplane Deployment", func() {
 			Expect(*podSpec.AutomountServiceAccountToken).To(BeFalse())
 		})
 	})
+
+	Describe("Kine container image override", func() {
+		var tcp kamajiv1alpha1.TenantControlPlane
+		BeforeEach(func() {
+			d.KineContainerImage = "rancher/kine:v0.11.0"
+			d.DataStore = kamajiv1alpha1.DataStore{
+				Spec: kamajiv1alpha1.DataStoreSpec{
+					Driver: kamajiv1alpha1.KinePostgreSQLDriver,
+				},
+			}
+			tcp = kamajiv1alpha1.TenantControlPlane{}
+			tcp.Status.Storage = kamajiv1alpha1.StorageStatus{
+				Config: kamajiv1alpha1.DataStoreConfigStatus{
+					SecretName: "test-secret",
+				},
+			}
+		})
+
+		It("should use default kine image when not overridden", func() {
+			podSpec := &corev1.PodSpec{}
+			tcp.Spec.ControlPlane.Deployment.AdditionalContainers = []corev1.Container{}
+
+			d.setAdditionalContainers(podSpec, tcp)
+			d.buildKine(podSpec, tcp)
+
+			found, index := utilities.HasNamedContainer(podSpec.Containers, "kine")
+			Expect(found).To(BeTrue())
+			Expect(podSpec.Containers[index].Image).To(Equal("rancher/kine:v0.11.0"))
+		})
+
+		It("should use custom kine image when overridden via additionalContainers", func() {
+			podSpec := &corev1.PodSpec{}
+			tcp.Spec.ControlPlane.Deployment.AdditionalContainers = []corev1.Container{
+				{
+					Name:  "kine",
+					Image: "my-custom-kine:v1.0.0",
+				},
+			}
+
+			d.setAdditionalContainers(podSpec, tcp)
+			d.buildKine(podSpec, tcp)
+
+			found, index := utilities.HasNamedContainer(podSpec.Containers, "kine")
+			Expect(found).To(BeTrue())
+			Expect(podSpec.Containers[index].Image).To(Equal("my-custom-kine:v1.0.0"))
+		})
+
+		It("should preserve custom kine container image when set via additionalContainers", func() {
+			podSpec := &corev1.PodSpec{}
+			tcp.Spec.ControlPlane.Deployment.AdditionalContainers = []corev1.Container{
+				{
+					Name:  "kine",
+					Image: "custom-kine:latest",
+				},
+			}
+
+			d.setAdditionalContainers(podSpec, tcp)
+			d.buildKine(podSpec, tcp)
+
+			found, index := utilities.HasNamedContainer(podSpec.Containers, "kine")
+			Expect(found).To(BeTrue())
+			Expect(podSpec.Containers[index].Image).To(Equal("custom-kine:latest"))
+		})
+	})
 })