Return error if app bundle contains settings.yml but not parameters.yml

Signed-off-by: Christopher Crone <christopher.crone@docker.com>

Author: chris-crone

internal/names.go

@@ -18,6 +18,9 @@ const (
 	ComposeFileName = "docker-compose.yml"
 	// ParametersFileName is parameters file name
 	ParametersFileName = "parameters.yml"
+
+	// DeprecatedSettingsFileName is the deprecated settings file name (replaced by ParametersFileName)
+	DeprecatedSettingsFileName = "settings.yml"
 )
 
 var (

loader/loader.go

@@ -5,8 +5,10 @@ import (
 	"io/ioutil"
 	"net/http"
 	"os"
+	"path/filepath"
 	"strings"
 
+	"github.com/docker/app/internal"
 	"github.com/docker/app/types"
 	"github.com/docker/docker/pkg/archive"
 	"github.com/pkg/errors"
@@ -53,6 +55,11 @@ func LoadFromSingleFile(path string, r io.Reader, ops ...func(*types.App) error)
 
 // LoadFromDirectory loads a docker app from a directory
 func LoadFromDirectory(path string, ops ...func(*types.App) error) (*types.App, error) {
+	if _, err := os.Stat(filepath.Join(path, internal.ParametersFileName)); os.IsNotExist(err) {
+		if _, err := os.Stat(filepath.Join(path, internal.DeprecatedSettingsFileName)); err == nil {
+			return nil, errors.Errorf("\"settings.yml\" has been deprecated in favor of \"parameters.yml\"; please rename \"settings.yml\" to \"parameters.yml\"")
+		}
+	}
 	return types.NewAppFromDefaultFiles(path, ops...)
 }
 

loader/loader_test.go

@@ -66,6 +66,18 @@ func TestLoadFromDirectory(t *testing.T) {
 	assertAppContent(t, app)
 }
 
+func TestLoadFromDirectoryDeprecatedSettings(t *testing.T) {
+	dir := fs.NewDir(t, "my-app",
+		fs.WithFile(internal.MetadataFileName, metadata),
+		fs.WithFile(internal.DeprecatedSettingsFileName, parameters),
+		fs.WithFile(internal.ComposeFileName, yaml),
+	)
+	defer dir.Remove()
+	app, err := LoadFromDirectory(dir.Path())
+	assert.Assert(t, app == nil)
+	assert.ErrorContains(t, err, "\"settings.yml\" has been deprecated in favor of \"parameters.yml\"; please rename \"settings.yml\" to \"parameters.yml\"")
+}
+
 func TestLoadFromTarInexistent(t *testing.T) {
 	_, err := LoadFromTar("any-tar.tar")
 	assert.ErrorContains(t, err, "open any-tar.tar")