runc/tty.go

137 lines
3.0 KiB
Go

// +build linux
package main
import (
"fmt"
"io"
"os"
"sync"
"github.com/docker/docker/pkg/term"
"github.com/opencontainers/runc/libcontainer"
)
// newTty creates a new tty for use with the container. If a tty is not to be
// created for the process, pipes are created so that the TTY of the parent
// process are not inherited by the container.
func newTty(create bool, p *libcontainer.Process, rootuid int, console string) (*tty, error) {
if create {
return createTty(p, rootuid, console)
}
return createStdioPipes(p, rootuid)
}
// setup standard pipes so that the TTY of the calling runc process
// is not inherited by the container.
func createStdioPipes(p *libcontainer.Process, rootuid int) (*tty, error) {
i, err := p.InitializeIO(rootuid)
if err != nil {
return nil, err
}
t := &tty{
closers: []io.Closer{
i.Stdin,
i.Stdout,
i.Stderr,
},
}
// add the process's io to the post start closers if they support close
for _, cc := range []interface{}{
p.Stdin,
p.Stdout,
p.Stderr,
} {
if c, ok := cc.(io.Closer); ok {
t.postStart = append(t.postStart, c)
}
}
go func() {
io.Copy(i.Stdin, os.Stdin)
i.Stdin.Close()
}()
t.wg.Add(2)
go t.copyIO(os.Stdout, i.Stdout)
go t.copyIO(os.Stderr, i.Stderr)
return t, nil
}
func (t *tty) copyIO(w io.Writer, r io.ReadCloser) {
defer t.wg.Done()
io.Copy(w, r)
r.Close()
}
func createTty(p *libcontainer.Process, rootuid int, consolePath string) (*tty, error) {
if consolePath != "" {
if err := p.ConsoleFromPath(consolePath); err != nil {
return nil, err
}
return &tty{}, nil
}
console, err := p.NewConsole(rootuid)
if err != nil {
return nil, err
}
go io.Copy(console, os.Stdin)
go io.Copy(os.Stdout, console)
state, err := term.SetRawTerminal(os.Stdin.Fd())
if err != nil {
return nil, fmt.Errorf("failed to set the terminal from the stdin: %v", err)
}
return &tty{
console: console,
state: state,
closers: []io.Closer{
console,
},
}, nil
}
type tty struct {
console libcontainer.Console
state *term.State
closers []io.Closer
postStart []io.Closer
wg sync.WaitGroup
}
// ClosePostStart closes any fds that are provided to the container and dup2'd
// so that we no longer have copy in our process.
func (t *tty) ClosePostStart() error {
for _, c := range t.postStart {
c.Close()
}
return nil
}
// Close closes all open fds for the tty and/or restores the orignal
// stdin state to what it was prior to the container execution
func (t *tty) Close() error {
// ensure that our side of the fds are always closed
for _, c := range t.postStart {
c.Close()
}
// wait for the copy routines to finish before closing the fds
t.wg.Wait()
for _, c := range t.closers {
c.Close()
}
if t.state != nil {
term.RestoreTerminal(os.Stdin.Fd(), t.state)
}
return nil
}
func (t *tty) resize() error {
if t.console == nil {
return nil
}
ws, err := term.GetWinsize(os.Stdin.Fd())
if err != nil {
return err
}
return term.SetWinsize(t.console.Fd(), ws)
}