Fix logs, so now, old and followed logs has same format without []

Signed-off-by: Alexander Morozov <lk4d4@docker.com>

daemon/logs.go

@@ -99,7 +99,8 @@ func (daemon *Daemon) ContainerLogs(job *engine.Job) engine.Status {
 				}
 				logLine := l.Log
 				if times {
-					logLine = fmt.Sprintf("%s %s", l.Created.Format(format), logLine)
+					// format can be "" or time format, so here can't be error
+					logLine, _ = l.Format(format)
 				}
 				if l.Stream == "stdout" && stdout {
 					io.WriteString(job.Stdout, logLine)

pkg/jsonlog/jsonlog.go

@@ -23,7 +23,7 @@ func (jl *JSONLog) Format(format string) (string, error) {
 		m, err := json.Marshal(jl)
 		return string(m), err
 	}
-	return fmt.Sprintf("[%s] %s", jl.Created.Format(format), jl.Log), nil
+	return fmt.Sprintf("%s %s", jl.Created.Format(format), jl.Log), nil
 }
 
 func (jl *JSONLog) Reset() {

pkg/jsonlog/jsonlog_test.go

@@ -30,7 +30,8 @@ func TestWriteLog(t *testing.T) {
 	if len(lines) != 30 {
 		t.Fatalf("Must be 30 lines but got %d", len(lines))
 	}
-	logRe := regexp.MustCompile(`\[.*\] Line that thinks that it is log line from docker`)
+	// 30+ symbols, five more can come from system timezone
+	logRe := regexp.MustCompile(`.{30,} Line that thinks that it is log line from docker`)
 	for _, l := range lines {
 		if !logRe.MatchString(l) {
 			t.Fatalf("Log line not in expected format: %q", l)