♻️ Refactor synchronization service

internal/syncer/backend/git/auth.go

@@ -0,0 +1,60 @@
+package git
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/go-git/go-git/v5/plumbing/transport"
+	"github.com/go-git/go-git/v5/plumbing/transport/http"
+	"github.com/go-git/go-git/v5/plumbing/transport/ssh"
+)
+
+// AuthConfig 描述 Git 鉴权方式。
+type AuthConfig struct {
+	Method         string
+	Username       string
+	Password       string
+	Token          string
+	SSHKeyPath     string
+	SSHKeyPassword string
+}
+
+const (
+	// AuthMethodToken 使用 Token 鉴权。
+	AuthMethodToken = "token"
+	// AuthMethodSSHKey 使用 SSH Key 鉴权。
+	AuthMethodSSHKey = "ssh_key"
+	// AuthMethodUserPass 使用用户名密码鉴权。
+	AuthMethodUserPass = "user_pass"
+)
+
+// authMethod 根据配置构造 go-git 鉴权实例。
+func authMethod(config AuthConfig) (transport.AuthMethod, error) {
+	switch config.Method {
+	case AuthMethodToken:
+		if config.Token == "" {
+			return nil, errors.New("git token is required")
+		}
+		return &http.BasicAuth{
+			Username: "git",
+			Password: config.Token,
+		}, nil
+	case AuthMethodUserPass:
+		if config.Username == "" || config.Password == "" {
+			return nil, errors.New("git username and password are required")
+		}
+		return &http.BasicAuth{
+			Username: config.Username,
+			Password: config.Password,
+		}, nil
+	case AuthMethodSSHKey:
+		if config.SSHKeyPath == "" {
+			return nil, errors.New("git ssh key path is required")
+		}
+		return ssh.NewPublicKeysFromFile("git", config.SSHKeyPath, config.SSHKeyPassword)
+	case "":
+		return nil, nil
+	default:
+		return nil, fmt.Errorf("unsupported git auth method: %s", config.Method)
+	}
+}