@@ -13,6 +13,7 @@ import (

 	"path"

 	"strconv"

 	"strings"

+	"time"

 	syslog "github.com/RackSec/srslog"

@@ -64,6 +65,17 @@ func init() {

 	}

 }

+// rsyslog uses appname part of syslog message to fill in an %syslogtag% template

+// attribute in rsyslog.conf. In order to be backward compatible to rfc3164

+// tag will be also used as an appname

+func rfc5424formatterWithAppNameAsTag(p syslog.Priority, hostname, tag, content string) string {

+	timestamp := time.Now().Format(time.RFC3339)

+	pid := os.Getpid()

+	msg := fmt.Sprintf("<%d>%d %s %s %s %d %s %s",

+		p, 1, timestamp, hostname, tag, pid, tag, content)

+	return msg

+}

+

 // New creates a syslog logger using the configuration passed in on

 // the context. Supported context configuration variables are

 // syslog-address, syslog-facility, & syslog-tag.

@@ -83,6 +95,11 @@ func New(ctx logger.Context) (logger.Logger, error) {

 		return nil, err

 	}

+	syslogFormatter, syslogFramer, err := parseLogFormat(ctx.Config["syslog-format"])

+	if err != nil {

+		return nil, err

+	}

+

 	logTag := path.Base(os.Args[0]) + "/" + tag

 	var log *syslog.Writer

@@ -100,6 +117,9 @@ func New(ctx logger.Context) (logger.Logger, error) {

 		return nil, err

 	}

+	log.SetFormatter(syslogFormatter)

+	log.SetFramer(syslogFramer)

+

 	return &syslogger{

 		writer: log,

 	}, nil

@@ -165,6 +185,7 @@ func ValidateLogOpt(cfg map[string]string) error {

 		case "syslog-tls-key":

 		case "syslog-tls-skip-verify":

 		case "tag":

+		case "syslog-format":

 		default:

 			return fmt.Errorf("unknown log opt '%s' for syslog log driver", key)

 		}

@@ -175,6 +196,9 @@ func ValidateLogOpt(cfg map[string]string) error {

 	if _, err := parseFacility(cfg["syslog-facility"]); err != nil {

 		return err

 	}

+	if _, _, err := parseLogFormat(cfg["syslog-format"]); err != nil {

+		return err

+	}

 	return nil

 }

@@ -207,3 +231,17 @@ func parseTLSConfig(cfg map[string]string) (*tls.Config, error) {

 	return tlsconfig.Client(opts)

 }

+

+func parseLogFormat(logFormat string) (syslog.Formatter, syslog.Framer, error) {

+	switch logFormat {

+	case "":

+		return syslog.UnixFormatter, syslog.DefaultFramer, nil

+	case "rfc3164":

+		return syslog.RFC3164Formatter, syslog.DefaultFramer, nil

+	case "rfc5424":

+		return rfc5424formatterWithAppNameAsTag, syslog.RFC5425MessageLengthFramer, nil

+	default:

+		return nil, nil, errors.New("Invalid syslog format")

+	}

+

+}

new file mode 100644

@@ -0,0 +1,45 @@

+// +build linux

+

+package syslog

+

+import (

+	syslog "github.com/RackSec/srslog"

+	"reflect"

+	"testing"

+)

+

+func functionMatches(expectedFun interface{}, actualFun interface{}) bool {

+	return reflect.ValueOf(expectedFun).Pointer() == reflect.ValueOf(actualFun).Pointer()

+}

+

+func TestParseLogFormat(t *testing.T) {

+	formatter, framer, err := parseLogFormat("rfc5424")

+	if err != nil || !functionMatches(rfc5424formatterWithAppNameAsTag, formatter) ||

+		!functionMatches(syslog.RFC5425MessageLengthFramer, framer) {

+		t.Fatal("Failed to parse rfc5424 format", err, formatter, framer)

+	}

+

+	formatter, framer, err = parseLogFormat("rfc3164")

+	if err != nil || !functionMatches(syslog.RFC3164Formatter, formatter) ||

+		!functionMatches(syslog.DefaultFramer, framer) {

+		t.Fatal("Failed to parse rfc3164 format", err, formatter, framer)

+	}

+

+	formatter, framer, err = parseLogFormat("")

+	if err != nil || !functionMatches(syslog.UnixFormatter, formatter) ||

+		!functionMatches(syslog.DefaultFramer, framer) {

+		t.Fatal("Failed to parse empty format", err, formatter, framer)

+	}

+

+	formatter, framer, err = parseLogFormat("invalid")

+	if err == nil {

+		t.Fatal("Failed to parse invalid format", err, formatter, framer)

+	}

+}

+

+func TestValidateLogOptEmpty(t *testing.T) {

+	emptyConfig := make(map[string]string)

+	if err := ValidateLogOpt(emptyConfig); err != nil {

+		t.Fatal("Failed to parse empty config", err)

+	}

+}

@@ -80,6 +80,7 @@ The following logging options are supported for the `syslog` logging driver:

     --log-opt syslog-tls-key=/etc/ca-certificates/custom/key.pem

     --log-opt syslog-tls-skip-verify=true

     --log-opt tag="mailer"

+    --log-opt syslog-format=[rfc5424|rfc3164] 

 `syslog-address` specifies the remote syslog server address where the driver connects to.

 If not specified it defaults to the local unix socket of the running system.

@@ -131,6 +132,11 @@ By default, Docker uses the first 12 characters of the container ID to tag log m

 Refer to the [log tag option documentation](log_tags.md) for customizing

 the log tag format.

+`syslog-format` specifies syslog message format to use when logging.

+If not specified it defaults to the local unix syslog format without hostname specification.

+Specify rfc3164 to perform logging in RFC-3164 compatible format. Specify rfc5424 to perform 

+logging in RFC-5424 compatible format

+

 ## journald options