func handleSingle(path string) error {
// Open a socket.
ln, err := net.Listen("unix", path)
if err != nil {
return err
}
defer ln.Close()
// We only accept a single connection, since we can only really have
// one reader for os.Stdin. Plus this is all a PoC.
conn, err := ln.Accept()
if err != nil {
return err
}
defer conn.Close()
// Close ln, to allow for other instances to take over.
ln.Close()
// Get the fd of the connection.
unixconn, ok := conn.(*net.UnixConn)
if !ok {
return fmt.Errorf("failed to cast to unixconn")
}
socket, err := unixconn.File()
if err != nil {
return err
}
defer socket.Close()
// Get the master file descriptor from runC.
master, err := utils.RecvFd(socket)
if err != nil {
return err
}
// Print the file descriptor tag.
ti, err := libcontainer.GetTerminalInfo(master.Name())
if err != nil {
return err
}
fmt.Printf("[recvtty] received masterfd: container '%s'\n", ti.ContainerID)
// Copy from our stdio to the master fd.
quitChan := make(chan struct{})
go func() {
io.Copy(os.Stdout, master)
quitChan <- struct{}{}
}()
go func() {
io.Copy(master, os.Stdin)
quitChan <- struct{}{}
}()
// Only close the master fd once we've stopped copying.
<-quitChan
master.Close()
return nil
}
func handleNull(path string) error {
// Open a socket.
ln, err := net.Listen("unix", path)
if err != nil {
return err
}
defer ln.Close()
// As opposed to handleSingle we accept as many connections as we get, but
// we don't interact with Stdin at all (and we copy stdout to /dev/null).
for {
conn, err := ln.Accept()
if err != nil {
return err
}
go func(conn net.Conn) {
// Don't leave references lying around.
defer conn.Close()
// Get the fd of the connection.
unixconn, ok := conn.(*net.UnixConn)
if !ok {
return
}
socket, err := unixconn.File()
if err != nil {
return
}
defer socket.Close()
// Get the master file descriptor from runC.
master, err := utils.RecvFd(socket)
if err != nil {
return
}
// Print the file descriptor tag.
ti, err := libcontainer.GetTerminalInfo(master.Name())
if err != nil {
bail(err)
}
fmt.Printf("[recvtty] received masterfd: container '%s'\n", ti.ContainerID)
// Just do a dumb copy to /dev/null.
devnull, err := os.OpenFile("/dev/null", os.O_RDWR, 0)
if err != nil {
// TODO: Handle this nicely.
return
}
io.Copy(devnull, master)
devnull.Close()
}(conn)
}
}