Merge pull request #16961 from vdemeester/pr-15975-carry-for-docs

Carry #15975 - Add extra fields based on label and env for gelf/fluentd/json-file/journald log drivers

daemon/container.go

@@ -721,6 +721,8 @@ func (container *Container) getLogger() (logger.Logger, error) {
 		ContainerImageID:    container.ImageID,
 		ContainerImageName:  container.Config.Image,
 		ContainerCreated:    container.Created,
+		ContainerEnv:        container.Config.Env,
+		ContainerLabels:     container.Config.Labels,
 	}
 
 	// Set logging file for "json-logger"

daemon/logger/context.go

@@ -17,9 +17,49 @@ type Context struct {
 	ContainerImageID    string
 	ContainerImageName  string
 	ContainerCreated    time.Time
+	ContainerEnv        []string
+	ContainerLabels     map[string]string
 	LogPath             string
 }
 
+// ExtraAttributes returns the user-defined extra attributes (labels,
+// environment variables) in key-value format. This can be used by log drivers
+// that support metadata to add more context to a log.
+func (ctx *Context) ExtraAttributes(keyMod func(string) string) map[string]string {
+	extra := make(map[string]string)
+	labels, ok := ctx.Config["labels"]
+	if ok && len(labels) > 0 {
+		for _, l := range strings.Split(labels, ",") {
+			if v, ok := ctx.ContainerLabels[l]; ok {
+				if keyMod != nil {
+					l = keyMod(l)
+				}
+				extra[l] = v
+			}
+		}
+	}
+
+	env, ok := ctx.Config["env"]
+	if ok && len(env) > 0 {
+		envMapping := make(map[string]string)
+		for _, e := range ctx.ContainerEnv {
+			if kv := strings.SplitN(e, "=", 2); len(kv) == 2 {
+				envMapping[kv[0]] = kv[1]
+			}
+		}
+		for _, l := range strings.Split(env, ",") {
+			if v, ok := envMapping[l]; ok {
+				if keyMod != nil {
+					l = keyMod(l)
+				}
+				extra[l] = v
+			}
+		}
+	}
+
+	return extra
+}
+
 // Hostname returns the hostname from the underlying OS.
 func (ctx *Context) Hostname() (string, error) {
 	hostname, err := os.Hostname()

daemon/logger/fluentd/fluentd.go

@@ -20,6 +20,7 @@ type fluentd struct {
 	containerID   string
 	containerName string
 	writer        *fluent.Fluent
+	extra         map[string]string
 }
 
 const (
@@ -51,9 +52,8 @@ func New(ctx logger.Context) (logger.Logger, error) {
 	if err != nil {
 		return nil, err
 	}
-
-	logrus.Debugf("logging driver fluentd configured for container:%s, host:%s, port:%d, tag:%s.", ctx.ContainerID, host, port, tag)
-
+	extra := ctx.ExtraAttributes(nil)
+	logrus.Debugf("logging driver fluentd configured for container:%s, host:%s, port:%d, tag:%s, extra:%v.", ctx.ContainerID, host, port, tag, extra)
 	// logger tries to recoonect 2**32 - 1 times
 	// failed (and panic) after 204 years [ 1.5 ** (2**32 - 1) - 1 seconds]
 	log, err := fluent.New(fluent.Config{FluentPort: port, FluentHost: host, RetryWait: 1000, MaxRetry: math.MaxInt32})
@@ -65,6 +65,7 @@ func New(ctx logger.Context) (logger.Logger, error) {
 		containerID:   ctx.ContainerID,
 		containerName: ctx.ContainerName,
 		writer:        log,
+		extra:         extra,
 	}, nil
 }
 
@@ -75,6 +76,9 @@ func (f *fluentd) Log(msg *logger.Message) error {
 		"source":         msg.Source,
 		"log":            string(msg.Line),
 	}
+	for k, v := range f.extra {
+		data[k] = v
+	}
 	// fluent-logger-golang buffers logs from failures and disconnections,
 	// and these are transferred again automatically.
 	return f.writer.PostWithTime(f.tag, msg.Timestamp, data)
@@ -95,6 +99,8 @@ func ValidateLogOpt(cfg map[string]string) error {
 		case "fluentd-address":
 		case "fluentd-tag":
 		case "tag":
+		case "labels":
+		case "env":
 		default:
 			return fmt.Errorf("unknown log opt '%s' for fluentd log driver", key)
 		}

daemon/logger/gelf/gelf.go

@@ -21,20 +21,10 @@ import (
 const name = "gelf"
 
 type gelfLogger struct {
-	writer *gelf.Writer
-	ctx    logger.Context
-	fields gelfFields
-}
-
-type gelfFields struct {
-	hostname      string
-	containerID   string
-	containerName string
-	imageID       string
-	imageName     string
-	command       string
-	tag           string
-	created       time.Time
+	writer   *gelf.Writer
+	ctx      logger.Context
+	hostname string
+	extra    map[string]interface{}
 }
 
 func init() {
@@ -71,15 +61,24 @@ func New(ctx logger.Context) (logger.Logger, error) {
 		return nil, err
 	}
 
-	fields := gelfFields{
-		hostname:      hostname,
-		containerID:   ctx.ContainerID,
-		containerName: string(containerName),
-		imageID:       ctx.ContainerImageID,
-		imageName:     ctx.ContainerImageName,
-		command:       ctx.Command(),
-		tag:           tag,
-		created:       ctx.ContainerCreated,
+	extra := map[string]interface{}{
+		"_container_id":   ctx.ContainerID,
+		"_container_name": string(containerName),
+		"_image_id":       ctx.ContainerImageID,
+		"_image_name":     ctx.ContainerImageName,
+		"_command":        ctx.Command(),
+		"_tag":            tag,
+		"_created":        ctx.ContainerCreated,
+	}
+
+	extraAttrs := ctx.ExtraAttributes(func(key string) string {
+		if key[0] == '_' {
+			return key
+		}
+		return "_" + key
+	})
+	for k, v := range extraAttrs {
+		extra[k] = v
 	}
 
 	// create new gelfWriter
@@ -89,9 +88,10 @@ func New(ctx logger.Context) (logger.Logger, error) {
 	}
 
 	return &gelfLogger{
-		writer: gelfWriter,
-		ctx:    ctx,
-		fields: fields,
+		writer:   gelfWriter,
+		ctx:      ctx,
+		hostname: hostname,
+		extra:    extra,
 	}, nil
 }
 
@@ -106,19 +106,11 @@ func (s *gelfLogger) Log(msg *logger.Message) error {
 
 	m := gelf.Message{
 		Version:  "1.1",
-		Host:     s.fields.hostname,
+		Host:     s.hostname,
 		Short:    string(short),
 		TimeUnix: float64(msg.Timestamp.UnixNano()/int64(time.Millisecond)) / 1000.0,
 		Level:    level,
-		Extra: map[string]interface{}{
-			"_container_id":   s.fields.containerID,
-			"_container_name": s.fields.containerName,
-			"_image_id":       s.fields.imageID,
-			"_image_name":     s.fields.imageName,
-			"_command":        s.fields.command,
-			"_tag":            s.fields.tag,
-			"_created":        s.fields.created,
-		},
+		Extra:    s.extra,
 	}
 
 	if err := s.writer.WriteMessage(&m); err != nil {
@@ -143,6 +135,8 @@ func ValidateLogOpt(cfg map[string]string) error {
 		case "gelf-address":
 		case "gelf-tag":
 		case "tag":
+		case "labels":
+		case "env":
 		default:
 			return fmt.Errorf("unknown log opt '%s' for gelf log driver", key)
 		}

daemon/logger/journald/journald.go

@@ -6,6 +6,7 @@ package journald
 
 import (
 	"fmt"
+	"strings"
 	"sync"
 
 	"github.com/Sirupsen/logrus"
@@ -46,10 +47,16 @@ func New(ctx logger.Context) (logger.Logger, error) {
 	if name[0] == '/' {
 		name = name[1:]
 	}
+
 	vars := map[string]string{
 		"CONTAINER_ID":      ctx.ContainerID[:12],
 		"CONTAINER_ID_FULL": ctx.ContainerID,
-		"CONTAINER_NAME":    name}
+		"CONTAINER_NAME":    name,
+	}
+	extraAttrs := ctx.ExtraAttributes(strings.ToTitle)
+	for k, v := range extraAttrs {
+		vars[k] = v
+	}
 	return &journald{vars: vars, readers: readerList{readers: make(map[*logger.LogWatcher]*logger.LogWatcher)}}, nil
 }
 
@@ -58,6 +65,8 @@ func New(ctx logger.Context) (logger.Logger, error) {
 func validateLogOpt(cfg map[string]string) error {
 	for key := range cfg {
 		switch key {
+		case "labels":
+		case "env":
 		default:
 			return fmt.Errorf("unknown log opt '%s' for journald log driver", key)
 		}

daemon/logger/jsonfilelog/jsonfilelog.go

@@ -41,6 +41,7 @@ type JSONFileLogger struct {
 	ctx          logger.Context
 	readers      map[*logger.LogWatcher]struct{} // stores the active log followers
 	notifyRotate *pubsub.Publisher
+	extra        []byte // json-encoded extra attributes
 }
 
 func init() {
@@ -77,6 +78,16 @@ func New(ctx logger.Context) (logger.Logger, error) {
 			return nil, fmt.Errorf("max-file cannot be less than 1")
 		}
 	}
+
+	var extra []byte
+	if attrs := ctx.ExtraAttributes(nil); len(attrs) > 0 {
+		var err error
+		extra, err = json.Marshal(attrs)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	return &JSONFileLogger{
 		f:            log,
 		buf:          bytes.NewBuffer(nil),
@@ -85,6 +96,7 @@ func New(ctx logger.Context) (logger.Logger, error) {
 		n:            maxFiles,
 		readers:      make(map[*logger.LogWatcher]struct{}),
 		notifyRotate: pubsub.NewPublisher(0, 1),
+		extra:        extra,
 	}, nil
 }
 
@@ -97,7 +109,12 @@ func (l *JSONFileLogger) Log(msg *logger.Message) error {
 	if err != nil {
 		return err
 	}
-	err = (&jsonlog.JSONLogs{Log: append(msg.Line, '\n'), Stream: msg.Source, Created: timestamp}).MarshalJSONBuf(l.buf)
+	err = (&jsonlog.JSONLogs{
+		Log:      append(msg.Line, '\n'),
+		Stream:   msg.Source,
+		Created:  timestamp,
+		RawAttrs: l.extra,
+	}).MarshalJSONBuf(l.buf)
 	if err != nil {
 		return err
 	}
@@ -181,6 +198,8 @@ func ValidateLogOpt(cfg map[string]string) error {
 		switch key {
 		case "max-file":
 		case "max-size":
+		case "labels":
+		case "env":
 		default:
 			return fmt.Errorf("unknown log opt '%s' for json-file log driver", key)
 		}

daemon/logger/jsonfilelog/jsonfilelog_test.go

@@ -1,9 +1,11 @@
 package jsonfilelog
 
 import (
+	"encoding/json"
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"reflect"
 	"strconv"
 	"testing"
 	"time"
@@ -149,3 +151,51 @@ func TestJSONFileLoggerWithOpts(t *testing.T) {
 	}
 
 }
+
+func TestJSONFileLoggerWithLabelsEnv(t *testing.T) {
+	cid := "a7317399f3f857173c6179d44823594f8294678dea9999662e5c625b5a1c7657"
+	tmp, err := ioutil.TempDir("", "docker-logger-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmp)
+	filename := filepath.Join(tmp, "container.log")
+	config := map[string]string{"labels": "rack,dc", "env": "environ,debug,ssl"}
+	l, err := New(logger.Context{
+		ContainerID:     cid,
+		LogPath:         filename,
+		Config:          config,
+		ContainerLabels: map[string]string{"rack": "101", "dc": "lhr"},
+		ContainerEnv:    []string{"environ=production", "debug=false", "port=10001", "ssl=true"},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+	if err := l.Log(&logger.Message{ContainerID: cid, Line: []byte("line"), Source: "src1"}); err != nil {
+		t.Fatal(err)
+	}
+	res, err := ioutil.ReadFile(filename)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var jsonLog jsonlog.JSONLogs
+	if err := json.Unmarshal(res, &jsonLog); err != nil {
+		t.Fatal(err)
+	}
+	extra := make(map[string]string)
+	if err := json.Unmarshal(jsonLog.RawAttrs, &extra); err != nil {
+		t.Fatal(err)
+	}
+	expected := map[string]string{
+		"rack":    "101",
+		"dc":      "lhr",
+		"environ": "production",
+		"debug":   "false",
+		"ssl":     "true",
+	}
+	if !reflect.DeepEqual(extra, expected) {
+		t.Fatalf("Wrong log attrs: %q, expected %q", extra, expected)
+	}
+}

docs/reference/logging/fluentd.md

@@ -73,6 +73,24 @@ Refer to the [log tag option documentation](log_tags.md) for customizing
 the log tag format.
 
 
+### labels and env
+
+The `labels` and `env` options takes a comma-separated list of keys. If there is collision between `label` and `env` keys, the value of the `env` takes precedence.
+
+To use attributes, specify them when you start the Docker daemon.
+
+```
+docker daemon --log-driver=fluentd --log-opt labels=foo --log-opt env=foo,fizz
+```
+
+Then, run a container and specify values for the `labels` or `env`.  For example, you might use this:
+
+```
+docker run --label foo=bar -e fizz=buzz -d -P training/webapp python app.py
+````
+
+This adds additional fields to the extra attributes of a logging message.
+
 ## Fluentd daemon management with Docker
 
 About `Fluentd` itself, see [the project webpage](http://www.fluentd.org)