add scheme to fluentd-address

Signed-off-by: Akira Koyasu <mail@akirakoyasu.net>

- add scheme to fluentd-address
- define a new type `location`
- use `errors.Wrapf`

daemon/logger/fluentd/fluentd.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"math"
 	"net"
+	"net/url"
 	"strconv"
 	"strings"
 	"time"
@@ -13,8 +14,10 @@ import (
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/daemon/logger"
 	"github.com/docker/docker/daemon/logger/loggerutils"
+	"github.com/docker/docker/pkg/urlutil"
 	"github.com/docker/go-units"
 	"github.com/fluent/fluent-logger-golang/fluent"
+	"github.com/pkg/errors"
 )
 
 type fluentd struct {
@@ -25,9 +28,17 @@ type fluentd struct {
 	extra         map[string]string
 }
 
+type location struct {
+	protocol string
+	host     string
+	port     int
+	path     string
+}
+
 const (
 	name = "fluentd"
 
+	defaultProtocol    = "tcp"
 	defaultHost        = "127.0.0.1"
 	defaultPort        = 24224
 	defaultBufferLimit = 1024 * 1024
@@ -60,7 +71,7 @@ func init() {
 // the context. The supported context configuration variable is
 // fluentd-address.
 func New(ctx logger.Context) (logger.Logger, error) {
-	host, port, err := parseAddress(ctx.Config[addressKey])
+	loc, err := parseAddress(ctx.Config[addressKey])
 	if err != nil {
 		return nil, err
 	}
@@ -107,8 +118,10 @@ func New(ctx logger.Context) (logger.Logger, error) {
 	}
 
 	fluentConfig := fluent.Config{
-		FluentPort:   port,
-		FluentHost:   host,
+		FluentPort:       loc.port,
+		FluentHost:       loc.host,
+		FluentNetwork:    loc.protocol,
+		FluentSocketPath: loc.path,
 		BufferLimit:      bufferLimit,
 		RetryWait:        retryWait,
 		MaxRetry:         maxRetries,
@@ -172,29 +185,65 @@ func ValidateLogOpt(cfg map[string]string) error {
 		}
 	}
 
-	if _, _, err := parseAddress(cfg["fluentd-address"]); err != nil {
+	if _, err := parseAddress(cfg["fluentd-address"]); err != nil {
 		return err
 	}
 
 	return nil
 }
 
-func parseAddress(address string) (string, int, error) {
+func parseAddress(address string) (*location, error) {
 	if address == "" {
-		return defaultHost, defaultPort, nil
+		return &location{
+			protocol: defaultProtocol,
+			host:     defaultHost,
+			port:     defaultPort,
+			path:     "",
+		}, nil
+	}
+
+	protocol := defaultProtocol
+	givenAddress := address
+	if urlutil.IsTransportURL(address) {
+		url, err := url.Parse(address)
+		if err != nil {
+			return nil, errors.Wrapf(err, "invalid fluentd-address %s", givenAddress)
+		}
+		// unix and unixgram socket
+		if url.Scheme == "unix" || url.Scheme == "unixgram" {
+			return &location{
+				protocol: url.Scheme,
+				host:     "",
+				port:     0,
+				path:     url.Path,
+			}, nil
+		}
+		// tcp|udp
+		protocol = url.Scheme
+		address = url.Host
 	}
 
 	host, port, err := net.SplitHostPort(address)
 	if err != nil {
 		if !strings.Contains(err.Error(), "missing port in address") {
-			return "", 0, fmt.Errorf("invalid fluentd-address %s: %s", address, err)
+			return nil, errors.Wrapf(err, "invalid fluentd-address %s", givenAddress)
 		}
-		return host, defaultPort, nil
+		return &location{
+			protocol: protocol,
+			host:     host,
+			port:     defaultPort,
+			path:     "",
+		}, nil
 	}
 
 	portnum, err := strconv.Atoi(port)
 	if err != nil {
-		return "", 0, fmt.Errorf("invalid fluentd-address %s: %s", address, err)
+		return nil, errors.Wrapf(err, "invalid fluentd-address %s", givenAddress)
 	}
-	return host, portnum, nil
+	return &location{
+		protocol: protocol,
+		host:     host,
+		port:     portnum,
+		path:     "",
+	}, nil
 }