traefik/vendor/github.com/docker/go-connections/sockets/unix_socket.go

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2017-02-07 21:33:23 +00:00
// +build linux freebsd solaris
package sockets
import (
"fmt"
"net"
"os"
"strconv"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/opencontainers/runc/libcontainer/user"
)
// NewUnixSocket creates a unix socket with the specified path and group.
func NewUnixSocket(path, group string) (net.Listener, error) {
if err := syscall.Unlink(path); err != nil && !os.IsNotExist(err) {
return nil, err
}
mask := syscall.Umask(0777)
defer syscall.Umask(mask)
l, err := net.Listen("unix", path)
if err != nil {
return nil, err
}
if err := setSocketGroup(path, group); err != nil {
l.Close()
return nil, err
}
if err := os.Chmod(path, 0660); err != nil {
l.Close()
return nil, err
}
return l, nil
}
func setSocketGroup(path, group string) error {
if group == "" {
return nil
}
if err := changeGroup(path, group); err != nil {
if group != "docker" {
return err
}
logrus.Debugf("Warning: could not change group %s to docker: %v", path, err)
}
return nil
}
func changeGroup(path string, nameOrGid string) error {
gid, err := lookupGidByName(nameOrGid)
if err != nil {
return err
}
logrus.Debugf("%s group found. gid: %d", nameOrGid, gid)
return os.Chown(path, 0, gid)
}
func lookupGidByName(nameOrGid string) (int, error) {
groupFile, err := user.GetGroupPath()
if err != nil {
return -1, err
}
groups, err := user.ParseGroupFileFilter(groupFile, func(g user.Group) bool {
return g.Name == nameOrGid || strconv.Itoa(g.Gid) == nameOrGid
})
if err != nil {
return -1, err
}
if groups != nil && len(groups) > 0 {
return groups[0].Gid, nil
}
gid, err := strconv.Atoi(nameOrGid)
if err == nil {
logrus.Warnf("Could not find GID %d", gid)
return gid, nil
}
return -1, fmt.Errorf("Group %s not found", nameOrGid)
}