new file mode 100644

@@ -0,0 +1,32 @@

+// +build !windows

+

+package listeners

+

+import (

+	"fmt"

+	"strconv"

+

+	"github.com/opencontainers/runc/libcontainer/user"

+	"github.com/pkg/errors"

+)

+

+func lookupGID(name string) (int, error) {

+	groupFile, err := user.GetGroupPath()

+	if err != nil {

+		return -1, errors.Wrap(err, "error looking up groups")

+	}

+	groups, err := user.ParseGroupFileFilter(groupFile, func(g user.Group) bool {

+		return g.Name == name || strconv.Itoa(g.Gid) == name

+	})

+	if err != nil {

+		return -1, errors.Wrapf(err, "error parsing groups for %s", name)

+	}

+	if groups != nil && len(groups) > 0 {

+		return groups[0].Gid, nil

+	}

+	gid, err := strconv.Atoi(name)

+	if err == nil {

+		return gid, nil

+	}

+	return -1, fmt.Errorf("group %s not found", name)

+}

@@ -18,7 +18,11 @@ func Init(proto, addr, socketGroup string, tlsConfig *tls.Config) (ls []net.List

 		}

 		ls = append(ls, l)

 	case "unix":

-		l, err := sockets.NewUnixSocket(addr, socketGroup)

+		gid, err := lookupGID(socketGroup)

+		if err != nil {

+			return nil, err

+		}

+		l, err := sockets.NewUnixSocket(addr, gid)

 		if err != nil {

 			return nil, fmt.Errorf("can't create unix socket %s: %v", addr, err)

 		}

@@ -31,10 +31,9 @@ func Init(proto, addr, socketGroup string, tlsConfig *tls.Config) ([]net.Listene

 		}

 		ls = append(ls, l)

 	case "unix":

-

-		gid, err := strconv.Atoi(socketGroup)

+		gid, err := lookupGID(socketGroup)

 		if err != nil {

-			return nil, fmt.Errorf("failed to parse socket group id: should be a number: %v", socketGroup)

+			return nil, err

 		}

 		l, err := sockets.NewUnixSocket(addr, gid)

 		if err != nil {