Add lua package search path for better module folder structure organize.

server/config.go

@@ -825,6 +825,7 @@ type RuntimeConfig struct {
 	LuaReadOnlyGlobals bool              `yaml:"lua_read_only_globals" json:"lua_read_only_globals" usage:"When enabled marks all Lua runtime global tables as read-only to reduce memory footprint. Default true."`
 	JsReadOnlyGlobals  bool              `yaml:"js_read_only_globals" json:"js_read_only_globals" usage:"When enabled marks all Javascript runtime globals as read-only to reduce memory footprint. Default true."`
 	LuaApiStacktrace   bool              `yaml:"lua_api_stacktrace" json:"lua_api_stacktrace" usage:"Include the Lua stacktrace in error responses returned to the client. Default false."`
+	LuaPaths           []string          `yaml:"lua_path" json:"lua_path" usage:"Lua default path directories."`
 	JsEntrypoint       string            `yaml:"js_entrypoint" json:"js_entrypoint" usage:"Specifies the location of the bundled JavaScript runtime source code."`
 }
 
@@ -886,6 +887,7 @@ func NewRuntimeConfig() *RuntimeConfig {
 		LuaReadOnlyGlobals: true,
 		JsReadOnlyGlobals:  true,
 		LuaApiStacktrace:   false,
+		LuaPaths:           make([]string, 0),
 	}
 }
 

server/runtime_lua.go

@@ -113,7 +113,8 @@ func NewRuntimeProviderLua(logger, startupLogger *zap.Logger, db *sql.DB, protoj
 	startupLogger.Info("Initialising Lua runtime provider", zap.String("path", rootPath))
 
 	// Load Lua modules into memory by reading the file contents. No evaluation/execution at this stage.
-	moduleCache, modulePaths, stdLibs, err := openLuaModules(startupLogger, rootPath, paths)
+	moduleCache, modulePaths, stdLibs, err := openLuaModules(startupLogger,
+		append([]string{rootPath}, config.GetRuntime().LuaPaths...), paths)
 	if err != nil {
 		// Errors already logged in the function call above.
 		return nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, err
@@ -1215,7 +1216,8 @@ func NewRuntimeProviderLua(logger, startupLogger *zap.Logger, db *sql.DB, protoj
 
 func CheckRuntimeProviderLua(logger *zap.Logger, config Config, version string, paths []string) error {
 	// Load Lua modules into memory by reading the file contents. No evaluation/execution at this stage.
-	moduleCache, _, stdLibs, err := openLuaModules(logger, config.GetRuntime().Path, paths)
+	moduleCache, _, stdLibs, err := openLuaModules(logger,
+		append([]string{config.GetRuntime().Path}, config.GetRuntime().LuaPaths...), paths)
 	if err != nil {
 		// Errors already logged in the function call above.
 		return err
@@ -1231,16 +1233,20 @@ func CheckRuntimeProviderLua(logger *zap.Logger, config Config, version string,
 	return nil
 }
 
-func openLuaModules(logger *zap.Logger, rootPath string, paths []string) (*RuntimeLuaModuleCache, []string, map[string]lua.LGFunction, error) {
+func openLuaModules(logger *zap.Logger, rootPaths []string, paths []string) (*RuntimeLuaModuleCache, []string, map[string]lua.LGFunction, error) {
 	moduleCache := &RuntimeLuaModuleCache{
 		Names:   make([]string, 0),
 		Modules: make(map[string]*RuntimeLuaModule, 0),
 	}
 	modulePaths := make([]string, 0)
 
 	// Override before Package library is invoked.
-	lua.LuaLDir = rootPath
-	lua.LuaPathDefault = lua.LuaLDir + string(os.PathSeparator) + "?.lua;" + lua.LuaLDir + string(os.PathSeparator) + "?" + string(os.PathSeparator) + "init.lua"
+	lua.LuaLDir = rootPaths[0]
+	lua.LuaPathDefault = lua.LuaLDir + lua.LuaDirSep + "?.lua;"
+	lua.LuaPathDefault += lua.LuaLDir + lua.LuaDirSep + "?" + lua.LuaDirSep + "init.lua;"
+	for i := 1; i < len(rootPaths); i++ {
+		lua.LuaPathDefault += filepath.Join(lua.LuaLDir, rootPaths[i]) + ";"
+	}
 	if err := os.Setenv(lua.LuaPath, lua.LuaPathDefault); err != nil {
 		logger.Error("Could not set Lua module path", zap.Error(err))
 		return nil, nil, nil, err
@@ -1259,7 +1265,7 @@ func openLuaModules(logger *zap.Logger, rootPath string, paths []string) (*Runti
 			return nil, nil, nil, err
 		}
 
-		relPath, _ := filepath.Rel(rootPath, path)
+		relPath, _ := filepath.Rel(rootPaths[0], path)
 		name := strings.TrimSuffix(relPath, filepath.Ext(relPath))
 		// Make paths Lua friendly.
 		name = strings.Replace(name, string(os.PathSeparator), ".", -1)

server/runtime_lua_loadlib.go

@@ -54,7 +54,18 @@ func OpenPackage(moduleCache *RuntimeLuaModuleCache) func(L *lua.LState) int {
 	return func(L *lua.LState) int {
 		loLoaderCache := func(L *lua.LState) int {
 			name := L.CheckString(1)
-			module, ok := moduleCache.Modules[name]
+			var ok bool
+			var module *RuntimeLuaModule
+			dir := lua.LuaLDir + lua.LuaDirSep
+			for _, path := range strings.Split(lua.LuaPathDefault, ";") {
+				path = strings.TrimPrefix(path, dir)
+				path = strings.TrimSuffix(path, ".lua")
+				path = strings.ReplaceAll(path, "?", name)
+				path = strings.ReplaceAll(path, lua.LuaDirSep, ".")
+				if module, ok = moduleCache.Modules[path]; ok {
+					break
+				}
+			}
 			if !ok {
 				L.Push(lua.LString(fmt.Sprintf("no cached module '%s'", name)))
 				return 1