distribution/registry/listener/listener.go
Anton Tiurin ad80cbe1ea [Server] Listen and serve on a unix socket
Allow to use a unix socket as a listener.
To specify an endpoint type we use an optional configuration
field 'net', as there's no way to distinguish a relative
socket path from a hostname.

Signed-off-by: Anton Tiurin <noxiouz@yandex.ru>
2015-05-11 16:00:14 +03:00

74 lines
1.7 KiB
Go

package listener
import (
"fmt"
"net"
"os"
"time"
)
// tcpKeepAliveListener sets TCP keep-alive timeouts on accepted
// connections. It's used by ListenAndServe and ListenAndServeTLS so
// dead TCP connections (e.g. closing laptop mid-download) eventually
// go away.
// it is a plain copy-paste from net/http/server.go
type tcpKeepAliveListener struct {
*net.TCPListener
}
func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
tc, err := ln.AcceptTCP()
if err != nil {
return
}
tc.SetKeepAlive(true)
tc.SetKeepAlivePeriod(3 * time.Minute)
return tc, nil
}
// NewListener announces on laddr and net. Accepted values of the net are
// 'unix' and 'tcp'
func NewListener(net, laddr string) (net.Listener, error) {
switch net {
case "unix":
return newUnixListener(laddr)
case "tcp", "": // an empty net means tcp
return newTCPListener(laddr)
default:
return nil, fmt.Errorf("unknown address type %s", net)
}
}
func newUnixListener(laddr string) (net.Listener, error) {
fi, err := os.Stat(laddr)
if err == nil {
// the file exists.
// try to remove it if it's a socket
if !isSocket(fi.Mode()) {
return nil, fmt.Errorf("file %s exists and is not a socket", laddr)
}
if err := os.Remove(laddr); err != nil {
return nil, err
}
} else if !os.IsNotExist(err) {
// we can't do stat on the file.
// it means we can not remove it
return nil, err
}
return net.Listen("unix", laddr)
}
func isSocket(m os.FileMode) bool {
return m&os.ModeSocket != 0
}
func newTCPListener(laddr string) (net.Listener, error) {
ln, err := net.Listen("tcp", laddr)
if err != nil {
return nil, err
}
return tcpKeepAliveListener{ln.(*net.TCPListener)}, nil
}