github.com/nguyentm83/docker@v1.5.0/daemon/logs.go (about)

     1  package daemon
     2  
     3  import (
     4  	"bytes"
     5  	"encoding/json"
     6  	"fmt"
     7  	"io"
     8  	"os"
     9  	"strconv"
    10  	"sync"
    11  
    12  	log "github.com/Sirupsen/logrus"
    13  	"github.com/docker/docker/engine"
    14  	"github.com/docker/docker/pkg/jsonlog"
    15  	"github.com/docker/docker/pkg/tailfile"
    16  	"github.com/docker/docker/pkg/timeutils"
    17  )
    18  
    19  func (daemon *Daemon) ContainerLogs(job *engine.Job) engine.Status {
    20  	if len(job.Args) != 1 {
    21  		return job.Errorf("Usage: %s CONTAINER\n", job.Name)
    22  	}
    23  
    24  	var (
    25  		name   = job.Args[0]
    26  		stdout = job.GetenvBool("stdout")
    27  		stderr = job.GetenvBool("stderr")
    28  		tail   = job.Getenv("tail")
    29  		follow = job.GetenvBool("follow")
    30  		times  = job.GetenvBool("timestamps")
    31  		lines  = -1
    32  		format string
    33  	)
    34  	if !(stdout || stderr) {
    35  		return job.Errorf("You must choose at least one stream")
    36  	}
    37  	if times {
    38  		format = timeutils.RFC3339NanoFixed
    39  	}
    40  	if tail == "" {
    41  		tail = "all"
    42  	}
    43  	container := daemon.Get(name)
    44  	if container == nil {
    45  		return job.Errorf("No such container: %s", name)
    46  	}
    47  	cLog, err := container.ReadLog("json")
    48  	if err != nil && os.IsNotExist(err) {
    49  		// Legacy logs
    50  		log.Debugf("Old logs format")
    51  		if stdout {
    52  			cLog, err := container.ReadLog("stdout")
    53  			if err != nil {
    54  				log.Errorf("Error reading logs (stdout): %s", err)
    55  			} else if _, err := io.Copy(job.Stdout, cLog); err != nil {
    56  				log.Errorf("Error streaming logs (stdout): %s", err)
    57  			}
    58  		}
    59  		if stderr {
    60  			cLog, err := container.ReadLog("stderr")
    61  			if err != nil {
    62  				log.Errorf("Error reading logs (stderr): %s", err)
    63  			} else if _, err := io.Copy(job.Stderr, cLog); err != nil {
    64  				log.Errorf("Error streaming logs (stderr): %s", err)
    65  			}
    66  		}
    67  	} else if err != nil {
    68  		log.Errorf("Error reading logs (json): %s", err)
    69  	} else {
    70  		if tail != "all" {
    71  			var err error
    72  			lines, err = strconv.Atoi(tail)
    73  			if err != nil {
    74  				log.Errorf("Failed to parse tail %s, error: %v, show all logs", tail, err)
    75  				lines = -1
    76  			}
    77  		}
    78  		if lines != 0 {
    79  			if lines > 0 {
    80  				f := cLog.(*os.File)
    81  				ls, err := tailfile.TailFile(f, lines)
    82  				if err != nil {
    83  					return job.Error(err)
    84  				}
    85  				tmp := bytes.NewBuffer([]byte{})
    86  				for _, l := range ls {
    87  					fmt.Fprintf(tmp, "%s\n", l)
    88  				}
    89  				cLog = tmp
    90  			}
    91  			dec := json.NewDecoder(cLog)
    92  			l := &jsonlog.JSONLog{}
    93  			for {
    94  				if err := dec.Decode(l); err == io.EOF {
    95  					break
    96  				} else if err != nil {
    97  					log.Errorf("Error streaming logs: %s", err)
    98  					break
    99  				}
   100  				logLine := l.Log
   101  				if times {
   102  					logLine = fmt.Sprintf("%s %s", l.Created.Format(format), logLine)
   103  				}
   104  				if l.Stream == "stdout" && stdout {
   105  					io.WriteString(job.Stdout, logLine)
   106  				}
   107  				if l.Stream == "stderr" && stderr {
   108  					io.WriteString(job.Stderr, logLine)
   109  				}
   110  				l.Reset()
   111  			}
   112  		}
   113  	}
   114  	if follow && container.IsRunning() {
   115  		errors := make(chan error, 2)
   116  		wg := sync.WaitGroup{}
   117  
   118  		if stdout {
   119  			wg.Add(1)
   120  			stdoutPipe := container.StdoutLogPipe()
   121  			defer stdoutPipe.Close()
   122  			go func() {
   123  				errors <- jsonlog.WriteLog(stdoutPipe, job.Stdout, format)
   124  				wg.Done()
   125  			}()
   126  		}
   127  		if stderr {
   128  			wg.Add(1)
   129  			stderrPipe := container.StderrLogPipe()
   130  			defer stderrPipe.Close()
   131  			go func() {
   132  				errors <- jsonlog.WriteLog(stderrPipe, job.Stderr, format)
   133  				wg.Done()
   134  			}()
   135  		}
   136  
   137  		wg.Wait()
   138  		close(errors)
   139  
   140  		for err := range errors {
   141  			if err != nil {
   142  				log.Errorf("%s", err)
   143  			}
   144  		}
   145  
   146  	}
   147  	return engine.StatusOK
   148  }