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moby--moby/daemon/logs.go
Brian Goff 0c84604f54 Fix goroutine leak on logs -f with no output
Also noticed potential hang when only stdout or stderr are used with
follow=1

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
2015-06-04 13:56:40 -07:00

179 lines
4.1 KiB
Go

package daemon
import (
"bytes"
"encoding/json"
"fmt"
"io"
"net"
"os"
"strconv"
"syscall"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/daemon/logger/jsonfilelog"
"github.com/docker/docker/pkg/jsonlog"
"github.com/docker/docker/pkg/stdcopy"
"github.com/docker/docker/pkg/tailfile"
"github.com/docker/docker/pkg/timeutils"
)
type ContainerLogsConfig struct {
Follow, Timestamps bool
Tail string
Since time.Time
UseStdout, UseStderr bool
OutStream io.Writer
Stop <-chan bool
}
func (daemon *Daemon) ContainerLogs(name string, config *ContainerLogsConfig) error {
var (
lines = -1
format string
)
if !(config.UseStdout || config.UseStderr) {
return fmt.Errorf("You must choose at least one stream")
}
if config.Timestamps {
format = timeutils.RFC3339NanoFixed
}
if config.Tail == "" {
config.Tail = "all"
}
container, err := daemon.Get(name)
if err != nil {
return err
}
var (
outStream = config.OutStream
errStream io.Writer
)
if !container.Config.Tty {
errStream = stdcopy.NewStdWriter(outStream, stdcopy.Stderr)
outStream = stdcopy.NewStdWriter(outStream, stdcopy.Stdout)
} else {
errStream = outStream
}
if container.LogDriverType() != jsonfilelog.Name {
return fmt.Errorf("\"logs\" endpoint is supported only for \"json-file\" logging driver")
}
logDriver, err := container.getLogger()
cLog, err := logDriver.GetReader()
if err != nil {
logrus.Errorf("Error reading logs: %s", err)
} else {
// json-file driver
if config.Tail != "all" {
var err error
lines, err = strconv.Atoi(config.Tail)
if err != nil {
logrus.Errorf("Failed to parse tail %s, error: %v, show all logs", config.Tail, err)
lines = -1
}
}
if lines != 0 {
if lines > 0 {
f := cLog.(*os.File)
ls, err := tailfile.TailFile(f, lines)
if err != nil {
return err
}
tmp := bytes.NewBuffer([]byte{})
for _, l := range ls {
fmt.Fprintf(tmp, "%s\n", l)
}
cLog = tmp
}
dec := json.NewDecoder(cLog)
l := &jsonlog.JSONLog{}
for {
l.Reset()
if err := dec.Decode(l); err == io.EOF {
break
} else if err != nil {
logrus.Errorf("Error streaming logs: %s", err)
break
}
logLine := l.Log
if !config.Since.IsZero() && l.Created.Before(config.Since) {
continue
}
if config.Timestamps {
// format can be "" or time format, so here can't be error
logLine, _ = l.Format(format)
}
if l.Stream == "stdout" && config.UseStdout {
io.WriteString(outStream, logLine)
}
if l.Stream == "stderr" && config.UseStderr {
io.WriteString(errStream, logLine)
}
}
}
}
if config.Follow && container.IsRunning() {
chErrStderr := make(chan error)
chErrStdout := make(chan error)
var stdoutPipe, stderrPipe io.ReadCloser
// write an empty chunk of data (this is to ensure that the
// HTTP Response is sent immediatly, even if the container has
// not yet produced any data)
outStream.Write(nil)
if config.UseStdout {
stdoutPipe = container.StdoutLogPipe()
go func() {
logrus.Debug("logs: stdout stream begin")
chErrStdout <- jsonlog.WriteLog(stdoutPipe, outStream, format, config.Since)
logrus.Debug("logs: stdout stream end")
}()
}
if config.UseStderr {
stderrPipe = container.StderrLogPipe()
go func() {
logrus.Debug("logs: stderr stream begin")
chErrStderr <- jsonlog.WriteLog(stderrPipe, errStream, format, config.Since)
logrus.Debug("logs: stderr stream end")
}()
}
select {
case err = <-chErrStderr:
if stdoutPipe != nil {
stdoutPipe.Close()
<-chErrStdout
}
case err = <-chErrStdout:
if stderrPipe != nil {
stderrPipe.Close()
<-chErrStderr
}
case <-config.Stop:
if stdoutPipe != nil {
stdoutPipe.Close()
<-chErrStdout
}
if stderrPipe != nil {
stderrPipe.Close()
<-chErrStderr
}
return nil
}
if err != nil && err != io.EOF && err != io.ErrClosedPipe {
if e, ok := err.(*net.OpError); ok && e.Err != syscall.EPIPE {
logrus.Errorf("error streaming logs: %v", err)
}
}
}
return nil
}