package daemon import ( "bytes" "encoding/json" "fmt" "io" "os" "strconv" "time" "github.com/docker/docker/pkg/log" "github.com/docker/docker/pkg/tailfile" "github.com/docker/docker/engine" "github.com/docker/docker/pkg/jsonlog" ) func (daemon *Daemon) ContainerLogs(job *engine.Job) engine.Status { if len(job.Args) != 1 { return job.Errorf("Usage: %s CONTAINER\n", job.Name) } var ( name = job.Args[0] stdout = job.GetenvBool("stdout") stderr = job.GetenvBool("stderr") tail = job.Getenv("tail") follow = job.GetenvBool("follow") times = job.GetenvBool("timestamps") lines = -1 format string ) if !(stdout || stderr) { return job.Errorf("You must choose at least one stream") } if times { format = time.RFC3339Nano } if tail == "" { tail = "all" } container := daemon.Get(name) if container == nil { return job.Errorf("No such container: %s", name) } cLog, err := container.ReadLog("json") if err != nil && os.IsNotExist(err) { // Legacy logs log.Debugf("Old logs format") if stdout { cLog, err := container.ReadLog("stdout") if err != nil { log.Errorf("Error reading logs (stdout): %s", err) } else if _, err := io.Copy(job.Stdout, cLog); err != nil { log.Errorf("Error streaming logs (stdout): %s", err) } } if stderr { cLog, err := container.ReadLog("stderr") if err != nil { log.Errorf("Error reading logs (stderr): %s", err) } else if _, err := io.Copy(job.Stderr, cLog); err != nil { log.Errorf("Error streaming logs (stderr): %s", err) } } } else if err != nil { log.Errorf("Error reading logs (json): %s", err) } else { if tail != "all" { var err error lines, err = strconv.Atoi(tail) if err != nil { log.Errorf("Failed to parse tail %s, error: %v, show all logs", tail, err) lines = -1 } } if lines != 0 { if lines > 0 { f := cLog.(*os.File) ls, err := tailfile.TailFile(f, lines) if err != nil { return job.Error(err) } tmp := bytes.NewBuffer([]byte{}) for _, l := range ls { fmt.Fprintf(tmp, "%s\n", l) } cLog = tmp } dec := json.NewDecoder(cLog) for { l := &jsonlog.JSONLog{} if err := dec.Decode(l); err == io.EOF { break } else if err != nil { log.Errorf("Error streaming logs: %s", err) break } logLine := l.Log if times { logLine = fmt.Sprintf("%s %s", l.Created.Format(format), logLine) } if l.Stream == "stdout" && stdout { fmt.Fprintf(job.Stdout, "%s", logLine) } if l.Stream == "stderr" && stderr { fmt.Fprintf(job.Stderr, "%s", logLine) } } } } if follow && container.IsRunning() { errors := make(chan error, 2) if stdout { stdoutPipe := container.StdoutLogPipe() go func() { errors <- jsonlog.WriteLog(stdoutPipe, job.Stdout, format) }() } if stderr { stderrPipe := container.StderrLogPipe() go func() { errors <- jsonlog.WriteLog(stderrPipe, job.Stderr, format) }() } err := <-errors if err != nil { log.Errorf("%s", err) } } return engine.StatusOK }