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>

docs/user-guide.md

@@ -200,8 +200,9 @@ The currently supported options are:
 | kompose.service.healthcheck.liveness.http_get_path  | kubernetes liveness httpGet path                                                     |
 | kompose.service.healthcheck.liveness.http_get_port  | kubernetes liveness httpGet port                                                     |
 | kompose.service.healthcheck.liveness.tcp_port       | kubernetes liveness tcpSocket port                                                   |
-| kompose.service.external-traffic-policy             | 'cluster', 'local', ''                                                               |
+| kompose.service.external-traffic-policy       | 'cluster', 'local', ''                                                   |                                                |
-| kompose.security-context.fsgroup                    | kubernetes pod security group fsgroup                                                |
+| kompose.security-context.fsgroup       |  kubernetes pod security group fsgroup                                                  |                                                |
+| kompose.volume.sub-path                        | kubernetes volume mount subpath                                                   |                                                |
 
 **Note**: `kompose.service.type` label should be defined with `ports` only (except for headless service), otherwise `kompose` will fail.
 
@@ -446,6 +447,20 @@ services:
     labels:
       kompose.security-context.fsgroup: 1001
 ```
+
+- `kompose.volume.sub-path` defines Kubernetes Container [VolumeMounts Subpath](https://kubernetes.io/docs/concepts/storage/volumes/#using-subpath).
+
+For example:
+
+```yaml
+version: '3.8'
+
+services:
+  pgadmin:
+    image: postgres
+    labels:
+      kompose.volume.sub-path: pg-data
+```
 ## Restart
 
 If you want to create normal pods without controller you can use `restart` construct of docker-compose to define that. Follow table below to see what happens on the `restart` value.

pkg/kobject/kobject.go

@@ -142,6 +142,7 @@ type ServiceConfig struct {
 	MemLimit                      types.UnitBytes    `compose:"mem_limit"`
 	MemReservation                types.UnitBytes    `compose:""`
 	DeployMode                    string             `compose:""`
+	VolumeMountSubPath            string             `compose:"kompose.volume.subpath"`
 	// DeployLabels mapping to kubernetes labels
 	DeployLabels       map[string]string  `compose:""`
 	DeployUpdateConfig types.UpdateConfig `compose:""`

pkg/loader/compose/compose.go

@@ -719,6 +719,8 @@ func parseKomposeLabels(labels map[string]string, serviceConfig *kobject.Service
 			serviceConfig.ImagePullSecret = value
 		case LabelImagePullPolicy:
 			serviceConfig.ImagePullPolicy = value
+		case LabelContainerVolumeSubpath:
+			serviceConfig.VolumeMountSubPath = value
 		default:
 			serviceConfig.Labels[key] = value
 		}

pkg/loader/compose/utils.go

@@ -81,6 +81,9 @@ const (
 	ServiceTypeHeadless = "Headless"
 	// LabelSecurityContextFsGroup defines the pod FsGroup
 	LabelSecurityContextFsGroup = "kompose.security-context.fsgroup"
+
+	// LabelContainerVolumeSubpath defines the volume mount subpath inside container
+	LabelContainerVolumeSubpath = "kompose.volume.subpath"
 )
 
 // load environment variables from compose file

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)
+			}
+		}
+	}
+}

script/test/cmd/tests_new.sh

@@ -247,6 +247,7 @@ k8s_output="$KOMPOSE_ROOT/script/test/fixtures/fsgroup/output-k8s.yaml"
 os_cmd="kompose --provider=openshift -f $KOMPOSE_ROOT/script/test/fixtures/fsgroup/docker-compose.yaml convert --stdout --with-kompose-annotation=false"
 os_output="$KOMPOSE_ROOT/script/test/fixtures/fsgroup/output-os.yaml"
 convert::expect_success_and_warning "$k8s_cmd" "$k8s_output"
+convert::expect_success_and_warning "$os_cmd" "$os_output"
 
 # Test support for compose.yaml file
 k8s_cmd="kompose -f $KOMPOSE_ROOT/script/test/fixtures/compose-file-support/docker-compose.yaml convert --stdout --with-kompose-annotation=false"
@@ -257,3 +258,12 @@ convert::expect_success "$k8s_cmd" "$k8s_output"
 k8s_cmd="kompose -f $KOMPOSE_ROOT/script/test/fixtures/compose-env-interpolation/docker-compose.yaml convert --stdout --with-kompose-annotation=false"
 k8s_output="$KOMPOSE_ROOT/script/test/fixtures/compose-env-interpolation/output-k8s.yaml"
 convert::expect_success "$k8s_cmd" "$k8s_output"
+convert::expect_success "$os_cmd" "$os_output"
+
+# Test support for subpath volume
+k8s_cmd="kompose -f $KOMPOSE_ROOT/script/test/fixtures/vols-subpath/docker-compose.yaml convert --stdout --with-kompose-annotation=false"
+k8s_output="$KOMPOSE_ROOT/script/test/fixtures/vols-subpath/output-k8s.yaml"
+os_cmd="kompose --provider=openshift -f $KOMPOSE_ROOT/script/test/fixtures/vols-subpath/docker-compose.yaml convert --stdout --with-kompose-annotation=false"
+os_output="$KOMPOSE_ROOT/script/test/fixtures/vols-subpath/output-os.yaml"
+convert::expect_success_and_warning "$k8s_cmd" "$k8s_output"
+convert::expect_success "$os_cmd" "$os_output"

script/test/fixtures/vols-subpath/docker-compose.yaml

@@ -0,0 +1,15 @@
+version: '3.8'
+volumes:
+  postgres-data:
+
+services:
+  postgres:
+    labels:
+      kompose.volume.subpath: test
+    image: postgres
+    environment:
+      POSTGRES_USER: dumb_postgres_user
+      POSTGRES_PASSWORD: postgres_password
+      POSTGRES_DB: dumb_db
+    volumes:
+      - postgres-data:/var/lib/postgresql/data

script/test/fixtures/vols-subpath/output-k8s.yaml

@@ -0,0 +1,80 @@
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  annotations:
+    kompose.volume.subpath: test
+  creationTimestamp: null
+  labels:
+    io.kompose.service: postgres
+  name: postgres
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      io.kompose.service: postgres
+  strategy:
+    type: Recreate
+  template:
+    metadata:
+      annotations:
+        kompose.volume.subpath: test
+      creationTimestamp: null
+      labels:
+        io.kompose.network/vols-subpath-default: "true"
+        io.kompose.service: postgres
+    spec:
+      containers:
+        - env:
+            - name: POSTGRES_DB
+              value: dumb_db
+            - name: POSTGRES_PASSWORD
+              value: postgres_password
+            - name: POSTGRES_USER
+              value: dumb_postgres_user
+          image: postgres
+          name: postgres
+          resources: {}
+          volumeMounts:
+            - mountPath: /var/lib/postgresql/data
+              name: postgres-data
+              subPath: test
+      restartPolicy: Always
+      volumes:
+        - name: postgres-data
+          persistentVolumeClaim:
+            claimName: postgres-data
+status: {}
+
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  creationTimestamp: null
+  labels:
+    io.kompose.service: postgres-data
+  name: postgres-data
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 100Mi
+status: {}
+
+---
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  creationTimestamp: null
+  name: vols-subpath-default
+spec:
+  ingress:
+    - from:
+        - podSelector:
+            matchLabels:
+              io.kompose.network/vols-subpath-default: "true"
+  podSelector:
+    matchLabels:
+      io.kompose.network/vols-subpath-default: "true"
+

script/test/fixtures/vols-subpath/output-os.yaml

@@ -0,0 +1,103 @@
+---
+apiVersion: apps.openshift.io/v1
+kind: DeploymentConfig
+metadata:
+  annotations:
+    kompose.volume.subpath: test
+  creationTimestamp: null
+  labels:
+    io.kompose.service: postgres
+  name: postgres
+spec:
+  replicas: 1
+  selector:
+    io.kompose.service: postgres
+  strategy:
+    resources: {}
+    type: Recreate
+  template:
+    metadata:
+      creationTimestamp: null
+      labels:
+        io.kompose.network/vols-subpath-default: "true"
+        io.kompose.service: postgres
+    spec:
+      containers:
+        - env:
+            - name: POSTGRES_DB
+              value: dumb_db
+            - name: POSTGRES_PASSWORD
+              value: postgres_password
+            - name: POSTGRES_USER
+              value: dumb_postgres_user
+          image: ' '
+          name: postgres
+          resources: {}
+          volumeMounts:
+            - mountPath: /var/lib/postgresql/data
+              name: postgres-data
+              subPath: test
+      restartPolicy: Always
+      volumes:
+        - name: postgres-data
+          persistentVolumeClaim:
+            claimName: postgres-data
+  test: false
+  triggers:
+    - type: ConfigChange
+    - imageChangeParams:
+        automatic: true
+        containerNames:
+          - postgres
+        from:
+          kind: ImageStreamTag
+          name: postgres:latest
+      type: ImageChange
+status:
+  availableReplicas: 0
+  latestVersion: 0
+  observedGeneration: 0
+  replicas: 0
+  unavailableReplicas: 0
+  updatedReplicas: 0
+
+---
+apiVersion: image.openshift.io/v1
+kind: ImageStream
+metadata:
+  creationTimestamp: null
+  labels:
+    io.kompose.service: postgres
+  name: postgres
+spec:
+  lookupPolicy:
+    local: false
+  tags:
+    - annotations: null
+      from:
+        kind: DockerImage
+        name: postgres
+      generation: null
+      importPolicy: {}
+      name: latest
+      referencePolicy:
+        type: ""
+status:
+  dockerImageRepository: ""
+
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  creationTimestamp: null
+  labels:
+    io.kompose.service: postgres-data
+  name: postgres-data
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 100Mi
+status: {}
+