daemon/logger/gelf: remove uses of pkg/urlutil.IsTransportURL()

pkg/urlutil (despite its poorly chosen name) is not really intended as a generic
utility to handle URLs, and should only be used by the builder to handle (remote)
build contexts.

This patch:

- removes a redundant use of urlutil.IsTransportURL(); code further below already
  checked if the given scheme (protocol) was supported.
- renames some variables that collided with imported packages.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

daemon/logger/gelf/gelf.go

@@ -14,7 +14,6 @@ import (
 	"github.com/Graylog2/go-gelf/gelf"
 	"github.com/docker/docker/daemon/logger"
 	"github.com/docker/docker/daemon/logger/loggerutils"
-	"github.com/docker/docker/pkg/urlutil"
 	"github.com/sirupsen/logrus"
 )
 
@@ -251,23 +250,18 @@ func parseAddress(address string) (*url.URL, error) {
 	if address == "" {
 		return nil, fmt.Errorf("gelf-address is a required parameter")
 	}
-	if !urlutil.IsTransportURL(address) {
-		return nil, fmt.Errorf("gelf-address should be in form proto://address, got %v", address)
-	}
-	url, err := url.Parse(address)
+	addr, err := url.Parse(address)
 	if err != nil {
 		return nil, err
 	}
 
-	// we support only udp
-	if url.Scheme != "udp" && url.Scheme != "tcp" {
+	if addr.Scheme != "udp" && addr.Scheme != "tcp" {
 		return nil, fmt.Errorf("gelf: endpoint needs to be TCP or UDP")
 	}
 
-	// get host and port
-	if _, _, err = net.SplitHostPort(url.Host); err != nil {
+	if _, _, err = net.SplitHostPort(addr.Host); err != nil {
 		return nil, fmt.Errorf("gelf: please provide gelf-address as proto://host:port")
 	}
 
-	return url, nil
+	return addr, nil
 }

daemon/logger/gelf/gelf_test.go

@@ -223,12 +223,12 @@ func TestNewTCP(t *testing.T) {
 		ContainerID: "12345678901234567890",
 	}
 
-	logger, err := New(info)
+	gelfLogger, err := New(info)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = logger.Close()
+	err = gelfLogger.Close()
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -250,12 +250,12 @@ func TestNewUDP(t *testing.T) {
 		ContainerID: "12345678901234567890",
 	}
 
-	logger, err := New(info)
+	gelfLogger, err := New(info)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = logger.Close()
+	err = gelfLogger.Close()
 	if err != nil {
 		t.Fatal(err)
 	}