Add config option to change prefix for Content-Disposition filename. Defaults to backup.

internal/backer/loadConfig.go

@@ -128,6 +128,13 @@ func LoadConfig(path string) error {
 		return errors.New("Option password is not set")
 	}
 
+	// FilenamePrefix: default.
+	if C.FilenamePrefix == "" {
+		C.FilenamePrefix = "backup"
+
+		log.Warnf("Config option filename_prefix is not set, fallback to %s", C.FilenamePrefix)
+	}
+
 	// Compile exclude patterns.
 	excludePatterns = make([]*regexp.Regexp, 0, len(C.ExcludePatterns))
 

internal/backer/loadConfig_test.go

@@ -170,6 +170,27 @@ func TestLoadConfigNoHTTPS(t *testing.T) {
 	}
 }
 
+// TestLoadConfigFilenamePrefixCustom tests custom filename prefix.
+func TestLoadConfigFilenamePrefixCustom(t *testing.T) {
+	config := `{
+		"user": "test",
+		"password": "test",
+		"directories": ["../../test_data/test1/foo"],
+		"nohttps": true,
+		"filename_prefix": "mybackup"
+	}`
+	tmpFile := writeTempConfig(t, config)
+
+	err := LoadConfig(tmpFile)
+	if err != nil {
+		t.Errorf("Expected no error, got %v", err)
+	}
+
+	if C.FilenamePrefix != "mybackup" {
+		t.Errorf("C.FilenamePrefix should be mybackup, got %s", C.FilenamePrefix)
+	}
+}
+
 // TestLoadConfigDefaultValues tests default values are set correctly.
 func TestLoadConfigDefaultValues(t *testing.T) {
 	config := `{
@@ -201,6 +222,10 @@ func TestLoadConfigDefaultValues(t *testing.T) {
 	if C.LogLevel != "info" {
 		t.Errorf("C.LogLevel should default to info, got %s", C.LogLevel)
 	}
+
+	if C.FilenamePrefix != "backup" {
+		t.Errorf("C.FilenamePrefix should default to backup, got %s", C.FilenamePrefix)
+	}
 }
 
 // writeTempConfig is a helper to write a temp config file for testing.

internal/backer/newServer.go

@@ -82,7 +82,7 @@ func NewServer(configPath string) (*http.Server, error) {
 		}()
 
 		timestamp := time.Now().Format("20060102-150405")
-		filename := fmt.Sprintf("backup-%s.tar.gz", timestamp)
+		filename := fmt.Sprintf("%s-%s.tar.gz", C.FilenamePrefix, timestamp)
 
 		w.Header().Set("Content-Disposition", "attachment; filename="+filename)
 		w.Header().Set("Content-Type", "application/octet-stream")

internal/backer/types.go

@@ -17,6 +17,7 @@ type (
 		BackupTimeout    int      `json:"backup_timeout"`    // Timeout in minutes for backup streaming.
 		CompressionLevel int      `json:"compression_level"` // Gzip compression level (1-9, default 9).
 		ExcludePatterns  []string `json:"exclude_patterns"`  // Regex patterns to exclude from backup.
+		FilenamePrefix   string   `json:"filename_prefix"`   // Prefix for backup filename (default: "backup").
 	}
 )