fix: default directory for the sqlite db

The default directory of the sqlite db has now been changed depending of
the user who executes flucky.

The place where the sqlite db will be stored is unchanged for the root
user, but for all other users the sqlite db will now be created to
~/.cache/flucky

cli/root.go

@@ -76,14 +76,21 @@ func preRunError(cmd *cobra.Command, args []string) error {
 		}
 		postgresTimeStamp = time.Date(postgresTimeStamp.Year(), postgresTimeStamp.Month(), postgresTimeStamp.Day(), postgresTimeStamp.Hour(), postgresTimeStamp.Minute(), postgresTimeStamp.Second(), int(math.Round(float64(postgresTimeStamp.Nanosecond())/1000000)*1000000), location)
 
+		// default cache directory
+		defaultCacheDir, err := getDefaultCacheDir()
+		if err != nil {
+			return err
+		}
+
 		// Default configuration
+		dsn := fmt.Sprintf("sqlite3://%v/sqlite.db?cache=shared&mode=memory&foreign_keys=on", defaultCacheDir)
 		cnf := config.Config{
 			Device: &types.Device{
 				ID:           uuid.NewV4().String(),
 				Name:         hostname,
 				CreationDate: postgresTimeStamp,
 			},
-			DSN: "sqlite3:///var/log/flucky/sqlite.db?cache=shared&mode=memory&foreign_keys=on",
+			DSN: dsn,
 		}
 
 		err = config.Write(&cnf, configFile)
@@ -95,8 +102,8 @@ func preRunError(cmd *cobra.Command, args []string) error {
 	return nil
 }
 
-// GetDefaultConfigPath returns the default path to the configuration of
-// rpm-distributor
+// getDefaultConfigFile returns the default path to the configuration file of
+// flucky
 func getDefaultConfigFile() (string, error) {
 	u, err := user.Current()
 	if err != nil {
@@ -110,3 +117,19 @@ func getDefaultConfigFile() (string, error) {
 		return filepath.Join(u.HomeDir, ".config/flucky/config.json"), nil
 	}
 }
+
+// getDefaultCacheDir returns the default path to the cache directory where
+// flucky stores his measured values.
+func getDefaultCacheDir() (string, error) {
+	u, err := user.Current()
+	if err != nil {
+		return "", fmt.Errorf("Can not read current user: %v", err)
+	}
+
+	switch u.Uid {
+	case "0":
+		return "/var/cache/flucky", nil
+	default:
+		return filepath.Join(u.HomeDir, ".cache/flucky"), nil
+	}
+}