package events import ( "context" "fmt" "os" "time" "github.com/containers/podman/v3/pkg/util" "github.com/containers/storage/pkg/lockfile" "github.com/pkg/errors" ) // EventLogFile is the structure for event writing to a logfile. It contains the eventer // options and the event itself. Methods for reading and writing are also defined from it. type EventLogFile struct { options EventerOptions } // Writes to the log file func (e EventLogFile) Write(ee Event) error { // We need to lock events file lock, err := lockfile.GetLockfile(e.options.LogFilePath + ".lock") if err != nil { return err } lock.Lock() defer lock.Unlock() f, err := os.OpenFile(e.options.LogFilePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0700) if err != nil { return err } defer f.Close() eventJSONString, err := ee.ToJSONString() if err != nil { return err } if _, err := f.WriteString(fmt.Sprintf("%s\n", eventJSONString)); err != nil { return err } return nil } // Reads from the log file func (e EventLogFile) Read(ctx context.Context, options ReadOptions) error { defer close(options.EventChannel) filterMap, err := generateEventFilters(options.Filters, options.Since, options.Until) if err != nil { return errors.Wrapf(err, "failed to parse event filters") } t, err := e.getTail(options) if err != nil { return err } if len(options.Until) > 0 { untilTime, err := util.ParseInputTime(options.Until) if err != nil { return err } go func() { time.Sleep(time.Until(untilTime)) t.Stop() }() } funcDone := make(chan bool) copy := true go func() { select { case <-funcDone: // Do nothing case <-ctx.Done(): copy = false t.Kill(errors.New("hangup by client")) } }() for line := range t.Lines { select { case <-ctx.Done(): // the consumer has cancelled return nil default: // fallthrough } event, err := newEventFromJSONString(line.Text) if err != nil { return err } switch event.Type { case Image, Volume, Pod, System, Container, Network: // no-op default: return errors.Errorf("event type %s is not valid in %s", event.Type.String(), e.options.LogFilePath) } if copy && applyFilters(event, filterMap) { options.EventChannel <- event } } funcDone <- true return nil } // String returns a string representation of the logger func (e EventLogFile) String() string { return LogFile.String() }