env: fix path resolution with extends

* Fix an issue with `WithEnvFile` helper to not pass empty values
* Rewrite `env_file` paths from `extends` file to be relative to
  the included file rather than parent (this was a regression)
* Normalize `extends.file` path to be absolute when doing the same
  for other paths

See docker/compose#10258.

Signed-off-by: Milas Bowman <[email protected]>

cli/options.go

@@ -190,7 +190,11 @@ func WithOsEnv(o *ProjectOptions) error {
 // WithEnvFile set an alternate env file
 // deprecated - use WithEnvFiles
 func WithEnvFile(file string) ProjectOptionsFn {
-	return WithEnvFiles(file)
+	var files []string
+	if file != "" {
+		files = []string{file}
+	}
+	return WithEnvFiles(files...)
 }
 
 // WithEnvFiles set alternate env files

loader/loader.go

@@ -583,6 +583,10 @@ func loadServiceWithExtends(filename, name string, servicesDict map[string]inter
 				}
 				baseService.Volumes[i].Source = resolveMaybeUnixPath(vol.Source, baseFileParent, lookupEnv)
 			}
+
+			for i, envFile := range baseService.EnvFile {
+				baseService.EnvFile[i] = resolveMaybeUnixPath(envFile, baseFileParent, lookupEnv)
+			}
 		}
 
 		serviceConfig, err = _merge(baseService, serviceConfig)

loader/loader_test.go

@@ -1853,16 +1853,29 @@ func TestLoadWithExtends(t *testing.T) {
 	actual, err := Load(configDetails)
 	assert.NilError(t, err)
 
+	extendsDir, err := filepath.Abs(filepath.Join("testdata", "subdir"))
+	assert.NilError(t, err)
+
+	expectedEnvFilePath := filepath.Join(extendsDir, "extra.env")
+
+	expectedExtendsPath := filepath.Join(
+		extendsDir,
+		"compose-test-extends-imported.yaml",
+	)
+
 	expServices := types.Services{
 		{
 			Name:  "importer",
 			Image: "nginx",
 			Extends: types.ExtendsConfig{
-				"file":    strPtr("compose-test-extends-imported.yaml"),
+				"file":    &expectedExtendsPath,
 				"service": strPtr("imported"),
 			},
-			Environment: types.MappingWithEquals{},
-			Networks:    map[string]*types.ServiceNetworkConfig{"default": nil},
+			Environment: types.MappingWithEquals{
+				"SOURCE": strPtr("extends"),
+			},
+			EnvFile:  []string{expectedEnvFilePath},
+			Networks: map[string]*types.ServiceNetworkConfig{"default": nil},
 			Volumes: []types.ServiceVolumeConfig{{
 				Type:   "bind",
 				Source: "/opt/data",
@@ -1889,6 +1902,12 @@ func TestLoadWithExtendsWithContextUrl(t *testing.T) {
 	actual, err := Load(configDetails)
 	assert.NilError(t, err)
 
+	expectedExtendsPath, err := filepath.Abs(
+		filepath.Join(
+			"testdata",
+			"compose-test-extends-with-context-url-imported.yaml",
+		),
+	)
 	expServices := types.Services{
 		{
 			Name: "importer-with-https-url",
@@ -1897,7 +1916,7 @@ func TestLoadWithExtendsWithContextUrl(t *testing.T) {
 				Dockerfile: "Dockerfile",
 			},
 			Extends: types.ExtendsConfig{
-				"file":    strPtr("compose-test-extends-with-context-url-imported.yaml"),
+				"file":    &expectedExtendsPath,
 				"service": strPtr("imported-with-https-url"),
 			},
 			Environment: types.MappingWithEquals{},

loader/normalize.go

@@ -90,6 +90,11 @@ func normalize(project *types.Project, resolvePaths bool) error {
 		}
 		s.Environment = s.Environment.Resolve(fn)
 
+		if extendFile := s.Extends["file"]; extendFile != nil && *extendFile != "" {
+			p := absPath(project.WorkingDir, *extendFile)
+			s.Extends["file"] = &p
+		}
+
 		err := relocateLogDriver(&s)
 		if err != nil {
 			return err

loader/testdata/compose-test-extends.yaml

@@ -1,5 +1,5 @@
 services:
   importer:
     extends:
-      file: compose-test-extends-imported.yaml
+      file: subdir/compose-test-extends-imported.yaml
       service: imported

loader/testdata/compose-test-extends-imported.yaml → loader/testdata/subdir/compose-test-extends-imported.yaml

@@ -1,5 +1,7 @@
 services:
   imported:
     image: nginx
+    env_file:
+      - extra.env
     volumes:
       - /opt/data:/var/lib/mysql

loader/testdata/subdir/extra.env

@@ -0,0 +1 @@
+SOURCE=extends