Always use APP_ROOT and add AppRoot helper

config/config.go

@@ -38,10 +38,10 @@ const (
 )
 
 const (
+	_appRoot     = "APP_ROOT"
 	_environment = "_ENVIRONMENT"
 	_datacenter  = "_DATACENTER"
 	_configDir   = "_CONFIG_DIR"
-	_root        = "_ROOT"
 	_configRoot  = "./config"
 	_baseFile    = "base"
 	_secretsFile = "secrets"
@@ -59,6 +59,21 @@ var (
 	_devEnv = "development"
 )
 
+// AppRoot returns the root directory of your application. UberFx developers
+// can edit this via the APP_ROOT environment variable. If the environment
+// variable is not set then it will fallback to the current working directory.
+// This is often used for resolving relative paths in your service.
+func AppRoot() string {
+	if appRoot := os.Getenv(_appRoot); appRoot != "" {
+		return appRoot
+	}
+	if cwd, err := os.Getwd(); err != nil {
+		panic(fmt.Sprintf("Unable to get the current working directory: %s", err.Error()))
+	} else {
+		return cwd
+	}
+}
+
 func getConfigFiles() []string {
 	env := Environment()
 	dc := os.Getenv(EnvironmentPrefix() + _datacenter)

config/file_resolver.go

@@ -42,13 +42,7 @@ func NewRelativeResolver(paths ...string) FileResolver {
 
 	copy(pathList, paths)
 
-	if appRoot := os.Getenv(EnvironmentPrefix() + _root); appRoot != "" {
-		// add the app root
-		pathList = append(pathList, appRoot)
-	} else if cwd, err := os.Getwd(); err == nil {
-		// add the current cwd
-		pathList = append(pathList, cwd)
-	}
+	pathList = append(pathList, AppRoot())
 
 	// add the exe dir
 	pathList = append(pathList, path.Dir(os.Args[0]))

config/yaml_test.go

@@ -102,7 +102,7 @@ func TestAppRoot(t *testing.T) {
 	cwd, err := os.Getwd()
 	assert.NoError(t, err)
 
-	defer env.Override(t, "TEST_ROOT", path.Join(cwd, "testdata"))()
+	defer env.Override(t, _appRoot, path.Join(cwd, "testdata"))()
 	provider := NewYAMLProviderFromFiles(false, NewRelativeResolver(), "base.yaml", "dev.yaml", "secrets.yaml")
 
 	baseValue := provider.Get("value").AsString()