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|
package runc
import (
"io"
"os"
"os/exec"
"github.com/pkg/errors"
"golang.org/x/sys/unix"
)
type IO interface {
io.Closer
Stdin() io.WriteCloser
Stdout() io.ReadCloser
Stderr() io.ReadCloser
Set(*exec.Cmd)
}
type StartCloser interface {
CloseAfterStart() error
}
// NewPipeIO creates pipe pairs to be used with runc
func NewPipeIO(uid, gid int) (i IO, err error) {
var pipes []*pipe
// cleanup in case of an error
defer func() {
if err != nil {
for _, p := range pipes {
p.Close()
}
}
}()
stdin, err := newPipe()
if err != nil {
return nil, err
}
pipes = append(pipes, stdin)
if err = unix.Fchown(int(stdin.r.Fd()), uid, gid); err != nil {
return nil, errors.Wrap(err, "failed to chown stdin")
}
stdout, err := newPipe()
if err != nil {
return nil, err
}
pipes = append(pipes, stdout)
if err = unix.Fchown(int(stdout.w.Fd()), uid, gid); err != nil {
return nil, errors.Wrap(err, "failed to chown stdout")
}
stderr, err := newPipe()
if err != nil {
return nil, err
}
pipes = append(pipes, stderr)
if err = unix.Fchown(int(stderr.w.Fd()), uid, gid); err != nil {
return nil, errors.Wrap(err, "failed to chown stderr")
}
return &pipeIO{
in: stdin,
out: stdout,
err: stderr,
}, nil
}
func newPipe() (*pipe, error) {
r, w, err := os.Pipe()
if err != nil {
return nil, err
}
return &pipe{
r: r,
w: w,
}, nil
}
type pipe struct {
r *os.File
w *os.File
}
func (p *pipe) Close() error {
err := p.r.Close()
if werr := p.w.Close(); err == nil {
err = werr
}
return err
}
type pipeIO struct {
in *pipe
out *pipe
err *pipe
}
func (i *pipeIO) Stdin() io.WriteCloser {
return i.in.w
}
func (i *pipeIO) Stdout() io.ReadCloser {
return i.out.r
}
func (i *pipeIO) Stderr() io.ReadCloser {
return i.err.r
}
func (i *pipeIO) Close() error {
var err error
for _, v := range []*pipe{
i.in,
i.out,
i.err,
} {
if cerr := v.Close(); err == nil {
err = cerr
}
}
return err
}
func (i *pipeIO) CloseAfterStart() error {
for _, f := range []*os.File{
i.out.w,
i.err.w,
} {
f.Close()
}
return nil
}
// Set sets the io to the exec.Cmd
func (i *pipeIO) Set(cmd *exec.Cmd) {
cmd.Stdin = i.in.r
cmd.Stdout = i.out.w
cmd.Stderr = i.err.w
}
func NewSTDIO() (IO, error) {
return &stdio{}, nil
}
type stdio struct {
}
func (s *stdio) Close() error {
return nil
}
func (s *stdio) Set(cmd *exec.Cmd) {
cmd.Stdin = os.Stdin
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
}
func (s *stdio) Stdin() io.WriteCloser {
return os.Stdin
}
func (s *stdio) Stdout() io.ReadCloser {
return os.Stdout
}
func (s *stdio) Stderr() io.ReadCloser {
return os.Stderr
}
// NewNullIO returns IO setup for /dev/null use with runc
func NewNullIO() (IO, error) {
f, err := os.Open(os.DevNull)
if err != nil {
return nil, err
}
return &nullIO{
devNull: f,
}, nil
}
type nullIO struct {
devNull *os.File
}
func (n *nullIO) Close() error {
// this should be closed after start but if not
// make sure we close the file but don't return the error
n.devNull.Close()
return nil
}
func (n *nullIO) Stdin() io.WriteCloser {
return nil
}
func (n *nullIO) Stdout() io.ReadCloser {
return nil
}
func (n *nullIO) Stderr() io.ReadCloser {
return nil
}
func (n *nullIO) Set(c *exec.Cmd) {
// don't set STDIN here
c.Stdout = n.devNull
c.Stderr = n.devNull
}
func (n *nullIO) CloseAfterStart() error {
return n.devNull.Close()
}
|
