@@ -62,17 +62,21 @@ func New(info logger.Info) (logger.Logger, error) {

 		}

 	}

-	// no default template. only use a tag if the user asked for it

-	tag, err := loggerutils.ParseLogTag(info, "")

+	attrs, err := info.ExtraAttributes(nil)

 	if err != nil {

 		return nil, err

 	}

-	var extra []byte

-	attrs, err := info.ExtraAttributes(nil)

+	// no default template. only use a tag if the user asked for it

+	tag, err := loggerutils.ParseLogTag(info, "")

 	if err != nil {

 		return nil, err

 	}

+	if tag != "" {

+		attrs["tag"] = tag

+	}

+

+	var extra []byte

 	if len(attrs) > 0 {

 		var err error

 		extra, err = json.Marshal(attrs)

@@ -83,7 +87,7 @@ func New(info logger.Info) (logger.Logger, error) {

 	buf := bytes.NewBuffer(nil)

 	marshalFunc := func(msg *logger.Message) ([]byte, error) {

-		if err := marshalMessage(msg, extra, buf, tag); err != nil {

+		if err := marshalMessage(msg, extra, buf); err != nil {

 			return nil, err

 		}

 		b := buf.Bytes()

@@ -111,7 +115,7 @@ func (l *JSONFileLogger) Log(msg *logger.Message) error {

 	return err

 }

-func marshalMessage(msg *logger.Message, extra json.RawMessage, buf *bytes.Buffer, tag string) error {

+func marshalMessage(msg *logger.Message, extra json.RawMessage, buf *bytes.Buffer) error {

 	logLine := msg.Line

 	if !msg.Partial {

 		logLine = append(msg.Line, '\n')

@@ -121,7 +125,6 @@ func marshalMessage(msg *logger.Message, extra json.RawMessage, buf *bytes.Buffe

 		Stream:   msg.Source,

 		Created:  msg.Timestamp,

 		RawAttrs: extra,

-		Tag:      tag,

 	}).MarshalJSONBuf(buf)

 	if err != nil {

 		return errors.Wrap(err, "error writing log message to buffer")

@@ -14,6 +14,7 @@ import (

 	"github.com/docker/docker/daemon/logger"

 	"github.com/docker/docker/daemon/logger/jsonfilelog/jsonlog"

 	"github.com/gotestyourself/gotestyourself/fs"

+	"github.com/stretchr/testify/assert"

 	"github.com/stretchr/testify/require"

 )

@@ -90,14 +91,11 @@ func TestJSONFileLoggerWithTags(t *testing.T) {

 	res, err := ioutil.ReadFile(filename)

 	require.NoError(t, err)

-	expected := `{"log":"line1\n","stream":"src1","tag":"a7317399f3f8/test-container","time":"0001-01-01T00:00:00Z"}

-{"log":"line2\n","stream":"src2","tag":"a7317399f3f8/test-container","time":"0001-01-01T00:00:00Z"}

-{"log":"line3\n","stream":"src3","tag":"a7317399f3f8/test-container","time":"0001-01-01T00:00:00Z"}

+	expected := `{"log":"line1\n","stream":"src1","attrs":{"tag":"a7317399f3f8/test-container"},"time":"0001-01-01T00:00:00Z"}

+{"log":"line2\n","stream":"src2","attrs":{"tag":"a7317399f3f8/test-container"},"time":"0001-01-01T00:00:00Z"}

+{"log":"line3\n","stream":"src3","attrs":{"tag":"a7317399f3f8/test-container"},"time":"0001-01-01T00:00:00Z"}

 `

-

-	if string(res) != expected {

-		t.Fatalf("Wrong log content: %q, expected %q", res, expected)

-	}

+	assert.Equal(t, expected, string(res))

 }

 func BenchmarkJSONFileLoggerLog(b *testing.B) {

@@ -125,7 +123,7 @@ func BenchmarkJSONFileLoggerLog(b *testing.B) {

 	}

 	buf := bytes.NewBuffer(nil)

-	require.NoError(b, marshalMessage(msg, nil, buf, ""))

+	require.NoError(b, marshalMessage(msg, nil, buf))

 	b.SetBytes(int64(buf.Len()))

 	b.ResetTimer()

@@ -14,8 +14,6 @@ type JSONLog struct {

 	Created time.Time `json:"time"`

 	// Attrs is the list of extra attributes provided by the user

 	Attrs map[string]string `json:"attrs,omitempty"`

-	// Tags requested the operator

-	Tag string `json:"tag,omitempty"`

 }

 // Reset all fields to their zero value.

@@ -24,5 +22,4 @@ func (jl *JSONLog) Reset() {

 	jl.Stream = ""

 	jl.Created = time.Time{}

 	jl.Attrs = make(map[string]string)

-	jl.Tag = ""

 }

@@ -12,7 +12,6 @@ type JSONLogs struct {

 	Log     []byte    `json:"log,omitempty"`

 	Stream  string    `json:"stream,omitempty"`

 	Created time.Time `json:"time"`

-	Tag     string    `json:"tag,omitempty"`

 	// json-encoded bytes

 	RawAttrs json.RawMessage `json:"attrs,omitempty"`

@@ -38,15 +37,6 @@ func (mj *JSONLogs) MarshalJSONBuf(buf *bytes.Buffer) error {

 		buf.WriteString(`"stream":`)

 		ffjsonWriteJSONBytesAsString(buf, []byte(mj.Stream))

 	}

-	if len(mj.Tag) > 0 {

-		if first {

-			first = false

-		} else {

-			buf.WriteString(`,`)

-		}

-		buf.WriteString(`"tag":`)

-		ffjsonWriteJSONBytesAsString(buf, []byte(mj.Tag))

-	}

 	if len(mj.RawAttrs) > 0 {

 		if first {

 			first = false

@@ -30,7 +30,7 @@ func TestJSONLogsMarshalJSONBuf(t *testing.T) {

 		// with raw attributes

 		{Log: []byte("A log line"), RawAttrs: []byte(`{"hello":"world","value":1234}`)}: `^{\"log\":\"A log line\",\"attrs\":{\"hello\":\"world\",\"value\":1234},\"time\":`,

 		// with Tag set

-		{Log: []byte("A log line with tag"), Tag: "test-tag"}: `^{\"log\":\"A log line with tag\",\"tag\":\"test-tag\",\"time\":`,

+		{Log: []byte("A log line with tag"), RawAttrs: []byte(`{"hello":"world","value":1234}`)}: `^{\"log\":\"A log line with tag\",\"attrs\":{\"hello\":\"world\",\"value\":1234},\"time\":`,

 	}

 	for jsonLog, expression := range logs {

 		var buf bytes.Buffer

@@ -35,7 +35,7 @@ func BenchmarkJSONFileLoggerReadLogs(b *testing.B) {

 	}

 	buf := bytes.NewBuffer(nil)

-	require.NoError(b, marshalMessage(msg, nil, buf, ""))

+	require.NoError(b, marshalMessage(msg, nil, buf))

 	b.SetBytes(int64(buf.Len()))

 	b.ResetTimer()