feat: introduce config file

cmd/config.go

@@ -1,16 +1,58 @@
 package cmd
 
+import (
+	"encoding/json"
+	"github.com/pion/ice/v2"
+	"github.com/wiretrustee/wiretrustee/connection"
+	"io/ioutil"
+	"os"
+)
+
 type Config struct {
 	// Wireguard private key of local peer
 	PrivateKey string
 	// configured remote peers (Wireguard public keys)
-	Peers    string
-	StunURL  string
-	TurnURL  string
-	TurnUser string
-	TurnPwd  string
+	Peers        []connection.Peer
+	StunTurnURLs []*ice.URL
 	// host:port of the signal server
 	SignalAddr string
 	WgAddr     string
 	WgIface    string
 }
+
+//Write writes configPath to a file
+func (cfg *Config) Write(path string) error {
+	bs, err := json.Marshal(cfg)
+	if err != nil {
+		return err
+	}
+
+	err = ioutil.WriteFile(path, bs, 0600)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+//Read reads configPath from a file
+func Read(path string) (*Config, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	bs, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+
+	var cfg Config
+	err = json.Unmarshal(bs, &cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	return &cfg, nil
+}