package docker import ( "bufio" "bytes" "context" "encoding/json" "github.com/docker/docker/api/types" "github.com/pkg/errors" "github.com/pterodactyl/wings/environment" "strconv" ) type dockerLogLine struct { Log string `json:"log"` } var ErrNotAttached = errors.New("not attached to instance") func (e *Environment) setStream(s *types.HijackedResponse) { e.mu.Lock() e.stream = s e.mu.Unlock() } // Sends the specified command to the stdin of the running container instance. There is no // confirmation that this data is sent successfully, only that it gets pushed into the stdin. func (e *Environment) SendCommand(c string) error { if !e.IsAttached() { return ErrNotAttached } e.mu.RLock() defer e.mu.RUnlock() // If the command being processed is the same as the process stop command then we want to mark // the server as entering the stopping state otherwise the process will stop and Wings will think // it has crashed and attempt to restart it. if e.meta.Stop.Type == "command" && c == e.meta.Stop.Value { e.SetState(environment.ProcessStoppingState) } _, err := e.stream.Conn.Write([]byte(c + "\n")) return errors.WithStack(err) } // Reads the log file for the server. This does not care if the server is running or not, it will // simply try to read the last X bytes of the file and return them. func (e *Environment) Readlog(lines int) ([]string, error) { r, err := e.client.ContainerLogs(context.Background(), e.Id, types.ContainerLogsOptions{ ShowStdout: true, ShowStderr: true, Tail: strconv.Itoa(lines), }) if err != nil { return nil, errors.WithStack(err) } defer r.Close() var out []string scanner := bufio.NewScanner(r) for scanner.Scan() { out = append(out, scanner.Text()) } return out, nil } // Docker stores the logs for server output in a JSON format. This function will iterate over the JSON // that was read from the log file and parse it into a more human readable format. func (e *Environment) parseLogToStrings(b []byte) ([]string, error) { var hasError = false var out []string scanner := bufio.NewScanner(bytes.NewReader(b)) for scanner.Scan() { var l dockerLogLine // Unmarshal the contents and allow up to a single error before bailing out of the process. We // do this because if you're arbitrarily reading a length of the file you'll likely end up // with the first line in the output being improperly formatted JSON. In those cases we want to // just skip over it. However if we see another error we're going to bail out because that is an // abnormal situation. if err := json.Unmarshal([]byte(scanner.Text()), &l); err != nil { if hasError { return nil, err } hasError = true continue } out = append(out, l.Log) } return out, nil }