add function handling (basic)

internal/config/config.go

@@ -13,8 +13,13 @@ type ServerConfig struct {
 	LogPath         string `mapstructure:"log_path"`
 }
 
+type FuncConfig struct {
+	FunctionDir string `mapstructure:"func_dir"`
+}
+
 type Config struct {
-	Server ServerConfig `mapstructure:"server"`
+	Server    ServerConfig `mapstructure:"server"`
+	Functions FuncConfig   `mapstructure:"functions"`
 }
 
 var configPath atomic.Value // string
@@ -22,6 +27,8 @@ var defaults = map[string]any{
 	"server.port":       8080,
 	"server.address":    "127.0.0.0",
 	"server.static_dir": "./static",
+
+	"functions.func_dir": "./functions",
 }
 
 func read(cfg *Config) error {