feat: Add label_file support to service

loader/example1.label

@@ -0,0 +1,10 @@
+# passed through
+FOO=foo_from_label_file
+LABEL.WITH.DOT=ok
+LABEL_WITH_UNDERSCORE=ok
+
+# overridden in example2.label
+BAR=bar_from_label_file
+
+# overridden in full-example.yml
+BAZ=baz_from_label_file

loader/example2.label

@@ -0,0 +1,4 @@
+BAR=bar_from_label_file_2
+
+# overridden in configDetails.Labels
+QUX=quz_from_label_file_2

loader/full-example.yml

@@ -210,6 +210,10 @@ services:
     #   - "com.example.number=42"
     #   - "com.example.empty-label"
 
+    label_file:
+      - ./example1.label
+      - ./example2.label
+
     links:
      - db
      - db:database

loader/full-struct_test.go

@@ -217,10 +217,24 @@ func services(workingDir, homeDir string) types.Services {
 			Ipc:      "host",
 			Uts:      "host",
 			Labels: map[string]string{
+				"FOO":                     "foo_from_label_file",
+				"BAR":                     "bar_from_label_file_2",
+				"BAZ":                     "baz_from_label_file",
+				"QUX":                     "quz_from_label_file_2",
+				"LABEL.WITH.DOT":          "ok",
+				"LABEL_WITH_UNDERSCORE":   "ok",
 				"com.example.description": "Accounting webapp",
 				"com.example.number":      "42",
 				"com.example.empty-label": "",
 			},
+			LabelFiles: []types.LabelFile{
+				{
+					Path: filepath.Join(workingDir, "example1.label"),
+				},
+				{
+					Path: filepath.Join(workingDir, "example2.label"),
+				},
+			},
 			Links: []string{
 				"db",
 				"db:database",
@@ -770,9 +784,18 @@ services:
     image: redis
     ipc: host
     labels:
+      BAR: bar_from_label_file_2
+      BAZ: baz_from_label_file
+      FOO: foo_from_label_file
+      LABEL.WITH.DOT: ok
+      LABEL_WITH_UNDERSCORE: ok
+      QUX: quz_from_label_file_2
       com.example.description: Accounting webapp
       com.example.empty-label: ""
       com.example.number: "42"
+    label_file:
+      - %s
+      - %s
     links:
       - db
       - db:database
@@ -1058,6 +1081,8 @@ x-nested:
 		filepath.Join(workingDir, "bar"),
 		filepath.Join(workingDir, "example1.env"),
 		filepath.Join(workingDir, "example2.env"),
+		filepath.Join(workingDir, "example1.label"),
+		filepath.Join(workingDir, "example2.label"),
 		workingDir,
 		filepath.Join(workingDir, "static"),
 		filepath.Join(homeDir, "configs"),
@@ -1382,10 +1407,20 @@ func fullExampleJSON(workingDir, homeDir string) string {
       "image": "redis",
       "ipc": "host",
       "labels": {
+        "BAR": "bar_from_label_file_2",
+        "BAZ": "baz_from_label_file",
+        "FOO": "foo_from_label_file",
+        "LABEL.WITH.DOT": "ok",
+        "LABEL_WITH_UNDERSCORE": "ok",
+        "QUX": "quz_from_label_file_2",
         "com.example.description": "Accounting webapp",
         "com.example.empty-label": "",
         "com.example.number": "42"
       },
+      "label_file": [
+        "%s",
+        "%s"
+      ],
       "links": [
         "db",
         "db:database",
@@ -1707,6 +1742,8 @@ func fullExampleJSON(workingDir, homeDir string) string {
 		toPath(workingDir, "bar"),
 		toPath(workingDir, "example1.env"),
 		toPath(workingDir, "example2.env"),
+		toPath(workingDir, "example1.label"),
+		toPath(workingDir, "example2.label"),
 		toPath(workingDir),
 		toPath(workingDir, "static"),
 		toPath(homeDir, "configs"),

loader/loader.go

@@ -637,6 +637,12 @@ func modelToProject(dict map[string]interface{}, opts *Options, configDetails ty
 			return nil, err
 		}
 	}
+
+	project, err = project.WithServicesLabelsResolved(opts.discardEnvFiles)
+	if err != nil {
+		return nil, err
+	}
+
 	return project, nil
 }
 

loader/loader_test.go

@@ -2319,6 +2319,46 @@ func TestLoadServiceWithEnvFile(t *testing.T) {
 	assert.Equal(t, "YES", *service.Environment["HALLO"])
 }
 
+func TestLoadServiceWithLabelFile(t *testing.T) {
+	file, err := os.CreateTemp("", "test-compose-go")
+	assert.NilError(t, err)
+	defer os.Remove(file.Name())
+
+	_, err = file.Write([]byte("MY_LABEL=MY_VALUE"))
+	assert.NilError(t, err)
+
+	p := &types.Project{
+		Services: types.Services{
+			"test": {
+				Name: "test",
+				LabelFiles: []types.LabelFile{
+					{Path: file.Name()},
+				},
+			},
+		},
+	}
+	p, err = p.WithServicesLabelsResolved(false)
+	assert.NilError(t, err)
+	service, err := p.GetService("test")
+	assert.NilError(t, err)
+	assert.Equal(t, "MY_VALUE", service.Labels["MY_LABEL"])
+}
+
+func TestLoadServiceWithLabelFile_NotExists(t *testing.T) {
+	p := &types.Project{
+		Services: types.Services{
+			"test": {
+				Name: "test",
+				LabelFiles: []types.LabelFile{
+					{Path: "test"},
+				},
+			},
+		},
+	}
+	p, err := p.WithServicesLabelsResolved(false)
+	assert.ErrorContains(t, err, "label file test not found")
+}
+
 func TestLoadNoSSHInBuildConfig(t *testing.T) {
 	actual, err := loadYAML(`
 name: load-no-ssh-in-build-config

override/merge.go

@@ -57,6 +57,7 @@ func init() {
 	mergeSpecials["services.*.dns_search"] = mergeToSequence
 	mergeSpecials["services.*.entrypoint"] = override
 	mergeSpecials["services.*.env_file"] = mergeToSequence
+	mergeSpecials["services.*.label_file"] = mergeToSequence
 	mergeSpecials["services.*.environment"] = mergeToSequence
 	mergeSpecials["services.*.extra_hosts"] = mergeExtraHosts
 	mergeSpecials["services.*.healthcheck.test"] = override

override/uncity.go

@@ -51,6 +51,7 @@ func init() {
 	unique["services.*.env_file"] = envFileIndexer
 	unique["services.*.expose"] = exposeIndexer
 	unique["services.*.labels"] = keyValueIndexer
+	unique["services.*.label_file"] = labelFileIndexer
 	unique["services.*.links"] = keyValueIndexer
 	unique["services.*.networks.*.aliases"] = keyValueIndexer
 	unique["services.*.networks.*.link_local_ips"] = keyValueIndexer
@@ -227,3 +228,16 @@ func envFileIndexer(y any, p tree.Path) (string, error) {
 	}
 	return "", nil
 }
+
+func labelFileIndexer(y any, p tree.Path) (string, error) {
+	switch value := y.(type) {
+	case string:
+		return value, nil
+	case map[string]any:
+		if pathValue, ok := value["path"]; ok {
+			return pathValue.(string), nil
+		}
+		return "", fmt.Errorf("label path attribute %s is missing", p)
+	}
+	return "", nil
+}

paths/resolve.go

@@ -37,6 +37,7 @@ func ResolveRelativePaths(project map[string]any, base string, remotes []RemoteR
 		"services.*.build.context":               r.absContextPath,
 		"services.*.build.additional_contexts.*": r.absContextPath,
 		"services.*.env_file.*.path":             r.absPath,
+		"services.*.label_file.*.path":           r.absPath,
 		"services.*.extends.file":                r.absExtendsPath,
 		"services.*.develop.watch.*.path":        r.absSymbolicLink,
 		"services.*.volumes.*":                   r.absVolumeMount,

schema/compose-spec.json

@@ -240,6 +240,7 @@
         "domainname": {"type": "string"},
         "entrypoint": {"$ref": "#/definitions/command"},
         "env_file": {"$ref": "#/definitions/env_file"},
+        "label_file": {"$ref": "#/definitions/label_file"},
         "environment": {"$ref": "#/definitions/list_or_dict"},
 
         "expose": {
@@ -866,9 +867,6 @@
                   "path": {
                     "type": "string"
                   },
-                  "format": {
-                    "type": "string"
-                  },
                   "required": {
                     "type": ["boolean", "string"],
                     "default": true
@@ -884,6 +882,16 @@
       ]
     },
 
+    "label_file": {
+      "oneOf": [
+        {"type": "string"},
+        {
+          "type": "array",
+          "items": {"type": "string"}
+        }
+      ]
+    },
+
     "string_or_list": {
       "oneOf": [
         {"type": "string"},

transform/canonical.go

@@ -30,6 +30,7 @@ func init() {
 	transformers["services.*.build.additional_contexts"] = transformKeyValue
 	transformers["services.*.depends_on"] = transformDependsOn
 	transformers["services.*.env_file"] = transformEnvFile
+	transformers["services.*.label_file"] = transformLabelFile
 	transformers["services.*.extends"] = transformExtends
 	transformers["services.*.networks"] = transformServiceNetworks
 	transformers["services.*.volumes.*"] = transformVolumeMount

transform/labelfile.go

@@ -0,0 +1,55 @@
+/*
+   Copyright 2020 The Compose Specification Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package transform
+
+import (
+	"fmt"
+
+	"github.com/compose-spec/compose-go/v2/tree"
+)
+
+func transformLabelFile(data any, p tree.Path, _ bool) (any, error) {
+	switch v := data.(type) {
+	case string:
+		return []any{
+			transformLabelFileValue(v),
+		}, nil
+	case []any:
+		for i, e := range v {
+			v[i] = transformLabelFileValue(e)
+		}
+		return v, nil
+	default:
+		return nil, fmt.Errorf("%s: invalid type %T for label_file", p, v)
+	}
+}
+
+func transformLabelFileValue(data any) any {
+	switch v := data.(type) {
+	case string:
+		return map[string]any{
+			"path":     v,
+			"required": true,
+		}
+	case map[string]any:
+		if _, ok := v["required"]; !ok {
+			v["required"] = true
+		}
+		return v
+	}
+	return nil
+}

types/labelfile.go

@@ -0,0 +1,36 @@
+/*
+   Copyright 2020 The Compose Specification Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package types
+
+import (
+	"encoding/json"
+)
+
+type LabelFile struct {
+	Path   string `yaml:"path,omitempty" json:"path,omitempty"`
+	Format string `yaml:"format,omitempty" json:"format,omitempty"`
+}
+
+// MarshalYAML makes LabelFile implement yaml.Marshaler
+func (e LabelFile) MarshalYAML() (interface{}, error) {
+	return e.Path, nil
+}
+
+// MarshalJSON makes LabelFile implement json.Marshaler
+func (e *LabelFile) MarshalJSON() ([]byte, error) {
+	return json.Marshal(e.Path)
+}