Added support for tmpfs

fixes #436
This commit will add support for tmpfs, configEmptyVolumeSource
function is being modified as it have to work in two ways now.
(For emptyvols and tmpfs)
Added unit test for tmpfs too.

pkg/kobject/kobject.go

@@ -83,6 +83,7 @@ type ServiceConfig struct {
 	Stdin         bool                `compose:"stdin_open" bundle:""`
 	Tty           bool                `compose:"tty" bundle:""`
 	MemLimit      yaml.MemStringorInt `compose:"mem_limit" bundle:""`
+	TmpFs         []string            `compose:"tmpfs" bundle:""`
 }
 
 // EnvVar holds the environment variable struct of a container

pkg/loader/compose/compose.go

@@ -375,7 +375,7 @@ func (c *Compose) LoadFile(files []string) (kobject.KomposeObject, error) {
 		serviceConfig.Stdin = composeServiceConfig.StdinOpen
 		serviceConfig.Tty = composeServiceConfig.Tty
 		serviceConfig.MemLimit = composeServiceConfig.MemLimit
-
+		serviceConfig.TmpFs = composeServiceConfig.Tmpfs
 		komposeObject.ServiceConfigs[name] = serviceConfig
 	}
 

pkg/transformer/kubernetes/k8sutils.go

@@ -336,6 +336,18 @@ func (k *Kubernetes) UpdateKubernetesObjects(name string, service kobject.Servic
 	if err != nil {
 		return errors.Wrap(err, "k.ConfigVolumes failed")
 	}
+	// Configure Tmpfs
+	if len(service.TmpFs) > 0 {
+		TmpVolumesMount, TmpVolumes := k.ConfigTmpfs(name, service)
+
+		for _, volume := range TmpVolumes {
+			volumes = append(volumes, volume)
+		}
+		for _, vMount := range TmpVolumesMount {
+			volumesMount = append(volumesMount, vMount)
+		}
+
+	}
 
 	if pvc != nil {
 		// Looping on the slice pvc instead of `*objects = append(*objects, pvc...)`

pkg/transformer/kubernetes/kubernetes.go

@@ -324,6 +324,36 @@ func (k *Kubernetes) ConfigServicePorts(name string, service kobject.ServiceConf
 	return servicePorts
 }
 
+// ConfigTmpfs configure the tmpfs.
+func (k *Kubernetes) ConfigTmpfs(name string, service kobject.ServiceConfig) ([]api.VolumeMount, []api.Volume) {
+	//initializing volumemounts and volumes
+	volumeMounts := []api.VolumeMount{}
+	volumes := []api.Volume{}
+
+	for index, volume := range service.TmpFs {
+		//naming volumes if multiple tmpfs are provided
+		volumeName := fmt.Sprintf("%s-tmpfs%d", name, index)
+
+		// create a new volume mount object and append to list
+		volMount := api.VolumeMount{
+			Name:      volumeName,
+			MountPath: volume,
+		}
+		volumeMounts = append(volumeMounts, volMount)
+
+		//create tmpfs specific empty volumes
+		volSource := k.ConfigEmptyVolumeSource("tmpfs")
+
+		// create a new volume object using the volsource and add to list
+		vol := api.Volume{
+			Name:         volumeName,
+			VolumeSource: *volSource,
+		}
+		volumes = append(volumes, vol)
+	}
+	return volumeMounts, volumes
+}
+
 // ConfigVolumes configure the container volumes.
 func (k *Kubernetes) ConfigVolumes(name string, service kobject.ServiceConfig) ([]api.VolumeMount, []api.Volume, []*api.PersistentVolumeClaim, error) {
 	volumeMounts := []api.VolumeMount{}
@@ -369,7 +399,7 @@ func (k *Kubernetes) ConfigVolumes(name string, service kobject.ServiceConfig) (
 		// For PVC we will also create a PVC object and add to list
 		var volsource *api.VolumeSource
 		if useEmptyVolumes {
-			volsource = k.ConfigEmptyVolumeSource()
+			volsource = k.ConfigEmptyVolumeSource("volume")
 		} else {
 			volsource = k.ConfigPVCVolumeSource(volumeName, readonly)
 
@@ -396,10 +426,21 @@ func (k *Kubernetes) ConfigVolumes(name string, service kobject.ServiceConfig) (
 }
 
 // ConfigEmptyVolumeSource is helper function to create an EmptyDir api.VolumeSource
-func (k *Kubernetes) ConfigEmptyVolumeSource() *api.VolumeSource {
+//either for Tmpfs or for emptyvolumes
+func (k *Kubernetes) ConfigEmptyVolumeSource(key string) *api.VolumeSource {
+	//if key is tmpfs
+	if key == "tmpfs" {
+		return &api.VolumeSource{
+			EmptyDir: &api.EmptyDirVolumeSource{Medium: api.StorageMediumMemory},
+		}
+
+	}
+
+	//if key is volume
 	return &api.VolumeSource{
 		EmptyDir: &api.EmptyDirVolumeSource{},
 	}
+
 }
 
 // ConfigPVCVolumeSource is helper function to create an api.VolumeSource with a PVC

pkg/transformer/kubernetes/kubernetes_test.go

@@ -55,6 +55,7 @@ func newServiceConfig() kobject.ServiceConfig {
 		Restart:       "always",
 		Stdin:         true,
 		Tty:           true,
+		TmpFs:         []string{"/tmp"},
 	}
 }
 
@@ -499,3 +500,14 @@ func TestInitPodSpec(t *testing.T) {
 		t.Fatalf("Pod object not found")
 	}
 }
+
+func TestConfigTmpfs(t *testing.T) {
+	name := "foo"
+	k := Kubernetes{}
+	resultVolumeMount, resultVolume := k.ConfigTmpfs(name, newServiceConfig())
+
+	if resultVolumeMount[0].Name != "foo-tmpfs0" || resultVolume[0].EmptyDir.Medium != "Memory" {
+		t.Fatalf("Tmpfs not found")
+	}
+
+}