feat: support container volume mount subpath (#1628)

* feat: support volumes subpath

Signed-off-by: AhmedGrati <ahmedgrati1999@gmail.com>

* docs: add the kompose.volume.sub-path label

Signed-off-by: AhmedGrati <ahmedgrati1999@gmail.com>

* fix: update e2e tests

Signed-off-by: AhmedGrati <ahmedgrati1999@gmail.com>

---------

Signed-off-by: AhmedGrati <ahmedgrati1999@gmail.com>

pkg/transformer/kubernetes/kubernetes.go

@@ -887,6 +887,7 @@ func (k *Kubernetes) ConfigVolumes(name string, service kobject.ServiceConfig) (
 	var PVCs []*api.PersistentVolumeClaim
 	var cms []*api.ConfigMap
 	var volumeName string
+	var subpathName string
 
 	// Set a var based on if the user wants to use empty volumes
 	// as opposed to persistent volumes and volume claims
@@ -897,6 +898,10 @@ func (k *Kubernetes) ConfigVolumes(name string, service kobject.ServiceConfig) (
 		useEmptyVolumes = true
 	}
 
+	if subpath, ok := service.Labels["kompose.volume.subpath"]; ok {
+		subpathName = subpath
+	}
+
 	// Override volume type if specified in service labels.
 	if vt, ok := service.Labels["kompose.volume.type"]; ok {
 		if _, okk := ValidVolumeSet[vt]; !okk {
@@ -993,6 +998,9 @@ func (k *Kubernetes) ConfigVolumes(name string, service kobject.ServiceConfig) (
 				PVCs = append(PVCs, createdPVC)
 			}
 		}
+		if subpathName != "" {
+			volMount.SubPath = subpathName
+		}
 		volumeMounts = append(volumeMounts, volMount)
 
 		// create a new volume object using the volsource and add to list

pkg/transformer/kubernetes/kubernetes_test.go

@@ -104,6 +104,13 @@ func newServiceConfigWithExternalTrafficPolicy() kobject.ServiceConfig {
 	}
 }
 
+func newServiceConfigWithServiceVolumeMount(volumeMountSubPathValue string) kobject.ServiceConfig {
+	return kobject.ServiceConfig{
+		Name:               "app",
+		VolumeMountSubPath: volumeMountSubPathValue,
+	}
+}
+
 func equalStringSlice(s1, s2 []string) bool {
 	if len(s1) != len(s2) {
 		return false
@@ -1023,3 +1030,24 @@ func TestServiceExternalTrafficPolicy(t *testing.T) {
 		}
 	}
 }
+
+func TestVolumeMountSubPath(t *testing.T) {
+	groupName := "pod_group"
+	expectedSubPathValue := "test-subpath"
+	komposeObject := kobject.KomposeObject{
+		ServiceConfigs: map[string]kobject.ServiceConfig{"app": newServiceConfigWithServiceVolumeMount(expectedSubPathValue)},
+	}
+	k := Kubernetes{}
+	objs, err := k.Transform(komposeObject, kobject.ConvertOptions{ServiceGroupMode: groupName})
+	if err != nil {
+		t.Error(errors.Wrap(err, "k.Transform failed"))
+	}
+	for _, obj := range objs {
+		if deployment, ok := obj.(*appsv1.Deployment); ok {
+			volMountSubPath := deployment.Spec.Template.Spec.Containers[0].VolumeMounts[0].SubPath
+			if volMountSubPath != expectedSubPathValue {
+				t.Errorf("Expected VolumeMount Subpath %v, got %v", expectedSubPathValue, volMountSubPath)
+			}
+		}
+	}
+}