Add volume subpath option

Only supported in the long syntax.

Signed-off-by: Paweł Gronowski <[email protected]>

Author: vvoland

format/volume_test.go

@@ -177,6 +177,14 @@ func TestParseVolumeWithVolumeOptions(t *testing.T) {
 	assert.Check(t, is.DeepEqual(expected, volume))
 }
 
+func TestParseVolumeWithVolumeOptionsSubpath(t *testing.T) {
+	volume, err := ParseVolume("name:/target:nocopy,subpath=etc")
+	assert.NilError(t, err)
+
+	// subpath option is not supported in the short syntax
+	assert.Check(t, is.Equal(volume.Volume.Subpath, ""))
+}
+
 func TestParseVolumeWithReadOnly(t *testing.T) {
 	for _, path := range []string{"./foo", "/home/user"} {
 		volume, err := ParseVolume(path + ":/target:ro")

loader/loader_test.go

@@ -1390,6 +1390,23 @@ networks:
 	assert.Check(t, is.DeepEqual(expected, config.Networks))
 }
 
+func TestLoadVolumeSubpath(t *testing.T) {
+	config, err := loadYAML(`
+name: load-volume-subpath
+services:
+  test:
+    image: alpine:latest
+    volumes:
+      - type: volume
+        source: asdf
+        target: /app
+        volume:
+          subpath: etc/settings
+`)
+	assert.Check(t, err)
+	assert.Check(t, is.Equal(config.Services["test"].Volumes[0].Volume.Subpath, "etc/settings"))
+}
+
 func TestLoadExpandedPortFormat(t *testing.T) {
 	config, err := loadYAML(`
 name: load-expanded-port-format

schema/compose-spec.json

@@ -389,7 +389,8 @@
                   "volume": {
                     "type": "object",
                     "properties": {
-                      "nocopy": {"type": "boolean"}
+                      "nocopy": {"type": "boolean"},
+                      "subpath": {"type": "string"}
                     },
                     "additionalProperties": false,
                     "patternProperties": {"^x-": {}}

types/types.go

@@ -511,6 +511,9 @@ func (s ServiceVolumeConfig) String() string {
 	if s.Volume != nil && s.Volume.NoCopy {
 		options = append(options, "nocopy")
 	}
+	if s.Volume != nil && s.Volume.Subpath != "" {
+		options = append(options, s.Volume.Subpath)
+	}
 	return fmt.Sprintf("%s:%s:%s", s.Source, s.Target, strings.Join(options, ","))
 }
 
@@ -567,7 +570,8 @@ const (
 
 // ServiceVolumeVolume are options for a service volume of type volume
 type ServiceVolumeVolume struct {
-	NoCopy bool `yaml:"nocopy,omitempty" json:"nocopy,omitempty"`
+	NoCopy  bool   `yaml:"nocopy,omitempty" json:"nocopy,omitempty"`
+	Subpath string `yaml:"subpath,omitempty" json:"subpath,omitempty"`
 
 	Extensions Extensions `yaml:"#extensions,inline,omitempty" json:"-"`
 }