it just works

server/config/config_singleton.go

@@ -0,0 +1,60 @@
+package config
+
+import (
+	"os"
+	"sync"
+
+	"gopkg.in/yaml.v3"
+)
+
+var lock = &sync.Mutex{}
+
+type serverConfig struct {
+	Port           int    `yaml:"port"`
+	DownloadPath   string `yaml:"downloadPath"`
+	DownloaderPath string `yaml:"downloaderPath"`
+}
+
+type config struct {
+	cfg serverConfig
+}
+
+func (c *config) LoadFromFile(filename string) (serverConfig, error) {
+	bytes, err := os.ReadFile(filename)
+	if err != nil {
+		return serverConfig{}, err
+	}
+
+	yaml.Unmarshal(bytes, &c.cfg)
+
+	return c.cfg, nil
+}
+
+func (c *config) GetConfig() serverConfig {
+	return c.cfg
+}
+
+func (c *config) SetPort(port int) {
+	c.cfg.Port = port
+}
+
+func (c *config) DownloadPath(path string) {
+	c.cfg.DownloadPath = path
+}
+
+func (c *config) DownloaderPath(path string) {
+	c.cfg.DownloaderPath = path
+}
+
+var instance *config
+
+func Instance() *config {
+	if instance == nil {
+		lock.Lock()
+		defer lock.Unlock()
+		if instance == nil {
+			instance = &config{serverConfig{}}
+		}
+	}
+	return instance
+}