package config import ( "io" "os" "github.com/cloudflare/cloudflared/watcher" "github.com/pkg/errors" "github.com/rs/zerolog" "gopkg.in/yaml.v2" ) // Notifier sends out config updates type Notifier interface { ConfigDidUpdate(Root) } // Manager is the base functions of the config manager type Manager interface { Start(Notifier) error Shutdown() } // FileManager watches the yaml config for changes // sends updates to the service to reconfigure to match the updated config type FileManager struct { watcher watcher.Notifier notifier Notifier configPath string log *zerolog.Logger ReadConfig func(string, *zerolog.Logger) (Root, error) } // NewFileManager creates a config manager func NewFileManager(watcher watcher.Notifier, configPath string, log *zerolog.Logger) (*FileManager, error) { m := &FileManager{ watcher: watcher, configPath: configPath, log: log, ReadConfig: readConfigFromPath, } err := watcher.Add(configPath) return m, err } // Start starts the runloop to watch for config changes func (m *FileManager) Start(notifier Notifier) error { m.notifier = notifier // update the notifier with a fresh config on start config, err := m.GetConfig() if err != nil { return err } notifier.ConfigDidUpdate(config) m.watcher.Start(m) return nil } // GetConfig reads the yaml file from the disk func (m *FileManager) GetConfig() (Root, error) { return m.ReadConfig(m.configPath, m.log) } // Shutdown stops the watcher func (m *FileManager) Shutdown() { m.watcher.Shutdown() } func readConfigFromPath(configPath string, log *zerolog.Logger) (Root, error) { if configPath == "" { return Root{}, errors.New("unable to find config file") } file, err := os.Open(configPath) if err != nil { return Root{}, err } defer file.Close() var config Root if err := yaml.NewDecoder(file).Decode(&config); err != nil { if err == io.EOF { log.Error().Msgf("Configuration file %s was empty", configPath) return Root{}, nil } return Root{}, errors.Wrap(err, "error parsing YAML in config file at "+configPath) } return config, nil } // File change notifications from the watcher // WatcherItemDidChange triggers when the yaml config is updated // sends the updated config to the service to reload its state func (m *FileManager) WatcherItemDidChange(filepath string) { config, err := m.GetConfig() if err != nil { m.log.Error().Msgf("Failed to read new config: %s", err) return } m.log.Info().Msg("Config file has been updated") m.notifier.ConfigDidUpdate(config) } // WatcherDidError notifies of errors with the file watcher func (m *FileManager) WatcherDidError(err error) { m.log.Error().Msgf("Config watcher encountered an error: %s", err) }