k3s/vendor/github.com/containerd/go-runc/io.go
Darren Shepherd fa08d6076c Update vendor
2019-01-11 21:58:27 -07:00

219 lines
3.4 KiB
Go

/*
Copyright The containerd Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package runc
import (
"io"
"os"
"os/exec"
)
type IO interface {
io.Closer
Stdin() io.WriteCloser
Stdout() io.ReadCloser
Stderr() io.ReadCloser
Set(*exec.Cmd)
}
type StartCloser interface {
CloseAfterStart() error
}
// IOOpt sets I/O creation options
type IOOpt func(*IOOption)
// IOOption holds I/O creation options
type IOOption struct {
OpenStdin bool
OpenStdout bool
OpenStderr bool
}
func defaultIOOption() *IOOption {
return &IOOption{
OpenStdin: true,
OpenStdout: true,
OpenStderr: true,
}
}
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.w.Close()
if rerr := p.r.Close(); err == nil {
err = rerr
}
return err
}
type pipeIO struct {
in *pipe
out *pipe
err *pipe
}
func (i *pipeIO) Stdin() io.WriteCloser {
if i.in == nil {
return nil
}
return i.in.w
}
func (i *pipeIO) Stdout() io.ReadCloser {
if i.out == nil {
return nil
}
return i.out.r
}
func (i *pipeIO) Stderr() io.ReadCloser {
if i.err == nil {
return nil
}
return i.err.r
}
func (i *pipeIO) Close() error {
var err error
for _, v := range []*pipe{
i.in,
i.out,
i.err,
} {
if v != nil {
if cerr := v.Close(); err == nil {
err = cerr
}
}
}
return err
}
func (i *pipeIO) CloseAfterStart() error {
for _, f := range []*pipe{
i.out,
i.err,
} {
if f != nil {
f.w.Close()
}
}
return nil
}
// Set sets the io to the exec.Cmd
func (i *pipeIO) Set(cmd *exec.Cmd) {
if i.in != nil {
cmd.Stdin = i.in.r
}
if i.out != nil {
cmd.Stdout = i.out.w
}
if i.err != nil {
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()
}